Adafruit ESP32 WiFi User manual

Adafruit AirLift Shield - ESP32 WiFi Co-Processor

Created by Brent Rubell

Last updated on 2021-03-29 01:04:51 PM EDT

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Guide Contents

Guide Contents Overview Pinouts

Power Pins SPI Interface Pins ESP32 Control Pins SD Card Interface LEDs Prototyping Area

Assembly Installing Standard Headers

Stack Alert!

CircuitPython WiFi

CircuitPython Microcontroller Pinout

CircuitPython Installation of ESP32SPI Library CircuitPython Usage Internet Connect! What's a secrets file? Connect to WiFi Requests

HTTP GET with Requests HTTP POST with Requests Advanced Requests Usage

WiFi Manager CircuitPython BLE CircuitPython BLE UART Example Adafruit AirLift ESP32 Shield Wiring Update the AirLift Firmware Install CircuitPython Libraries Install the Adafruit Bluefruit LE Connect App Copy and Adjust the Example Program Talk to the AirLift via the Bluefruit LE Connect App Arduino WiFi Library Install First Test

Arduino Microcontroller Pin Definition

WiFi Connection Test Secure Connection Example

JSON Parsing Example Adapting Other Examples

Upgrade External ESP32 Airlift Firmware External AirLift FeatherWing, Shield, or ItsyWing

Upload Serial Passthrough code for Feather or ItsyBitsy

External AirLift Breakout Code Usage

Install esptool.py

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Burning nina-fw with esptool Verifying the Upgraded Firmware Version

Arduino CircuitPython

Downloads

Files Schematic Fab Print

Overview

Give your Arduino project a

lift

with the Adafruit AirLift Shield (https://adafru.it/F6v) - a shield that lets you

use the powerful ESP32 as a WiFi or BLE co-processor. You probably have your favorite Arduino-

compatible (like the Metro M4 (https://adafru.it/A5S) or the classic Metro

328 (https://adafru.it/METROXMETR)) that comes with its own set of awesome peripherals and lots of

libraries. But it doesn't have WiFi or BLE built in! So let's give that chip a best friend, the ESP32. This chip

can handle all the heavy lifting of connecting to a WiFi network and transferring data from a site, even if it's

using the latest TLS/SSL encryption (it has root certificates pre-burned in).

Having WiFi managed by a separate chip means your code is simpler, you don't have to cache socket

data, or compile in & debug an SSL library. Send basic but powerful socket-based commands over 8MHz

SPI for high speed data transfer. You can use any 3V or 5V Arduino, any chip from the ATmega328 and up

(although the '328 will not be able to do very complex tasks or buffer a lot of data). It also works great with

CircuitPython, a SAMD51/Cortex M4 minimum required since we need a bunch of RAM. All you need is the

SPI bus and 2 control pins plus a power supply that can provide up to 250mA during WiFi usage.

The ESP32 also supports BLE (Bluetooth Low Energy), though not simultaneously with WiFi. Many of our

CircuitPython builds include native support for ESP32 BLE. You use a few control pins and the RXI and

TXO pins to talk to the ESP32 when it's in BLE mode.

We placed an ESP32 module on a shield with a separate 3.3V regulator, and a tri-state chip for MOSI so

you can share the SPI bus with other shields. We also tossed on a micro SD card socket, you can use that

to host or store data you get from the Internet. Arduinos based on the ATmega328 (like the UNO) cannot

use both the WiFi module and SD library at the same time, they don't have enough RAM. Again, we

recommend an M0 or M4 chipset for use with Arduino, M4 for CircuitPython!

Comes fully assembled and tested, pre-programmed with ESP32 SPI WiFi co-processor firmware that you

can use in CircuitPython to use this into WiFi co-processsor (https://adafru.it/Evl). We also include some

header so you can solder it in and plug right into your Arduino-compatible, but you can also pick up a set

of stacking headers to stack above/below your board.

We've tested this with all our Metros and it should work just fine with them except the Metro M4

Airlifts (https://adafru.it/F6o) (because they already have WiFi!). For use in Arduino , the '328 and '32u4 you

can do basic connectivity and data transfer but they do not have a lot of RAM so we don't recommend

them - use the Metro M0, M4 or similar, for best results! For CircuitPython use, a Metro M4 works best -

the M0 series does not have enough RAM in CircuitPython.

The firmware on board is a slight variant of the Arduino WiFiNINA core, which works

great! (https://adafru.it/E7O) At this time connection to Enterprise WiFi is not yet supported.

Pinouts

There's a lot jam-packed into this shield! Let's take a look at what we've got going on.

Power Pins

GND - Common power/logic ground.

3V - this is the output from the 3.3V regulator. The regulator can supply 500mA peak but half of that

is drawn by the ESP32, and it's a fairly power-hungry chip.

5V - This is the input to the regulator

IOr - This is IORef, the IO voltage we will communicate with and is required.

SPI Interface Pins

Both ESP32 and SD card use SPI to send and receive data. These pins are labeled CLK MISO MOSI and

have level shifting so you can use this shield with 3.3V or 5V microcontroller boards.

By default the 2x3 pin ICSP header on the right hand side is where the SPI signals are found.

ESP32 Control Pins

Required Control Pins:

BUSY - this pin is an input from the AirLift, it will let us

know when its ready for more commands to be sent.

This is 3.3V logic out, can be read by 3-5V logic. This

must

be connected.

RST- this pin is an output to the AirLift. Set low to put the

AirLift into reset. You should use this pin, even though

you might be able to run for a short while without it, it's

essential to 'kick' the chip if it ever gets into a locked up

state. Level shifted so can be 3-5V logic

Optional Control Pins:

GPIO0 - this is the ESP32 GPIO0 pin, which is used to

put it into bootloading mode. It is also used if you like

when the ESP32 is acting as a server, to let you know

data is ready for reading. IIt's not required for WiFi, but

you'll need to connect it to use BLE mode. Solder the

pad on the bottom of the shield to connect it.

RX & TX - Serial data in and Serial data out, used for

bootloading new firmware, and for communication when

in BLE mode. Leave disconnected if not using BLE or

when not uploading new WiFi firmware to the AirLift

(which is a rare occurrence). You'll need to solder the

two pads on the bottom of the shield to use these pins.

SD Card Interface

There's a lot of space available on this shield so we also stuck

on a micro SD card holder, great for datalogging or storing

data to transmit over WiFi.

In addition to the shared SPI pins, the SD (chip select) pin is

also used. It can be re-assigned to any pin by cutting the trace

underneath the board and rewiring. If the SD card is not used,

the SD pin can be used for any other purpose

LEDs

There is a small RGB LED to the left of the ESP32. These RGB

LEDs are available in the Arduino and CircuitPython libraries if

you'd like to PWM them for a visual alert. They're connected

to the ESP32's pins 26 (Red), 25 (Green), and 27 (Blue).

Prototyping Area

We have a big grid of prototyping holes and power rails if you

want to make some custom circuitry!

Assembly

Installing Standard Headers

The shield comes with 0.1" standard header. Standard header does not permit stacking but it is

mechanically stronger and they're much less expensive too! If you want to stack a shield on top, do not

perform this step as it is not possible to uninstall the headers once soldered in! Skip down to the bottom

for the stacking tutorial

Break apart the 0.1" header into 6, 8 and/or 10-pin long pieces

and slip the long ends into the headers of your Arduino.

Place the assembled shield on top of the header-ed Arduino

so that all of the short parts of the header are sticking through

the outer set of pads

Solder each one of the pins into the shield to make a secure

connection

That's it! Now you can install the 2x3 header

Solder the 2x3 header so that it's pointing downwards

Stack Alert!

If you want to stack a shield on top of the WiFi Shield, you'll want to pick up some stacking headers and

use those instead of the plain header shown here!

Wanna stack? This tutorial shows how to use the plain header

to connect to an Arduino. If you want to use stacking

headers (https://adafru.it/dsu), don't follow these steps!

Start by sliding the 10 pin, 2 x 8 pin and 6-pin stacking

headers into the outer rows of the shield from the top. Then

flip the board over so its resting on the four headers. Pull on

the legs if necessary to straighten them out.

Tack one pin of each header, to get them set in place before

more soldering. If the headers go crooked you can re-heat the

one pin while re-positioning to straighten them up

Once you've tacked and straightened all the headers, go back

and solder the remaining pins for each header.

Insert the 2x3 stacking header as shown.

Solder into place.

CircuitPython WiFi

It's easy to use the Adafruit AirLift breakout with CircuitPython and the Adafruit CircuitPython

ESP32SPI (https://adafru.it/DWV) module. This module allows you to easily add WiFi to your project.

 The ESP32SPI library requires a microcontroller with ~128KB of RAM or more. The SAMD21 will not

work.

CircuitPython Microcontroller Pinout

To use the board's pins with the AirLift shield, copy the following lines into your code:

esp32_cs = DigitalInOut(board.D10) esp32_ready = DigitalInOut(board.D7) esp32_reset = DigitalInOut(board.D5)

If you wish to use the GPIO0 pin on the ESP32 - solder the jumper on the back of the shield, highlighted

below:

Then, include the following code to use the pin:

esp32_gpio0 = DigitalInOut(board.D6)

CircuitPython Installation of ESP32SPI Library

You'll need to install the Adafruit CircuitPython ESP32SPI (https://adafru.it/DWV) library on your

CircuitPython board.

First make sure you are running the latest version of Adafruit CircuitPython (https://adafru.it/Amd) for your

board.

Next you'll need to install the necessary libraries to use the hardware--carefully follow the steps to find and

install these libraries from Adafruit's CircuitPython library bundle (https://adafru.it/uap). Our CircuitPython

starter guide has a great page on how to install the library bundle (https://adafru.it/ABU).

You can manually install the necessary libraries from the bundle:

adafruit_esp32spi

adafruit_requests.mpy

adafruit_bus_device

Before continuing make sure your board's lib folder or root filesystem has the adafruit_esp32spi,

adafruit_requests.mpy, and adafruit_bus_device files and folders copied over.

Next make sure you are set up to connect to the serial console (https://adafru.it/Bec)

CircuitPython Usage

Copy the following code to your code.py file on your microcontroller:

import board import busio from digitalio import DigitalInOut

from adafruit_esp32spi import adafruit_esp32spi

print("ESP32 SPI hardware test")

esp32_cs = DigitalInOut(board.D10) esp32_ready = DigitalInOut(board.D7) esp32_reset = DigitalInOut(board.D5)

spi = busio.SPI(board.SCK, board.MOSI, board.MISO) esp = adafruit_esp32spi.ESP_SPIcontrol(spi, esp32_cs, esp32_ready, esp32_reset)

if esp.status == adafruit_esp32spi.WL_IDLE_STATUS: print("ESP32 found and in idle mode") print("Firmware vers.", esp.firmware_version) print("MAC addr:", [hex(i) for i in esp.MAC_address])

for ap in esp.scan_networks(): print("\t%s\t\tRSSI: %d" % (str(ap['ssid'], 'utf-8'), ap['rssi']))

print("Done!")

Connect to the serial console (https://adafru.it/BlO) to see the output. It should look something like the

following:

Make sure you see the same output! If you don't, check your wiring. Note that we've changed the pinout in

the code example above to reflect the CircuitPython Microcontroller Pinout at the top of this page.

Once you've succeeded, continue onto the next page!

 If you can read the Firmware and MAC address but fails on scanning SSIDs, check your power

supply, you may be running out of juice to the ESP32 and it's resetting

Internet Connect!

Once you have CircuitPython setup and libraries installed we can get your board connected to the

Internet.

To get connected, you will need to start by creating a

secrets file

.

What's a secrets file?

We expect people to share tons of projects as they build CircuitPython WiFi widgets. What we want to

avoid is people accidentally sharing their passwords or secret tokens and API keys. So, we designed all

our examples to use a secrets.py file, that is in your CIRCUITPY drive, to hold secret/private/custom data.

That way you can share your main project without worrying about accidentally sharing private stuff.

Your secrets.py file should look like this:

# This file is where you keep secret settings, passwords, and tokens! # If you put them in the code you risk committing that info or sharing it

secrets = { 'ssid' : 'home ssid', 'password' : 'my password', 'timezone' : "America/New_York", # http://worldtimeapi.org/timezones 'github_token' : 'fawfj23rakjnfawiefa', 'hackaday_token' : 'h4xx0rs3kret', }

Inside is a python dictionary named secrets with a line for each entry. Each entry has an entry name (say

'ssid' ) and then a colon to separate it from the entry key 'home ssid' and finally a comma ,

At a minimum you'll need the ssid and password for your local WiFi setup. As you make projects you may

need more tokens and keys, just add them one line at a time. See for example other tokens such as one

for accessing github or the hackaday API. Other non-secret data like your timezone can also go here, just

cause its called secrets doesn't mean you can't have general customization data in there!

For the correct time zone string, look at http://worldtimeapi.org/timezones (https://adafru.it/EcP) and

remember that if your city is not listed, look for a city in the same time zone, for example Boston, New

York, Philadelphia, Washington DC, and Miami are all on the same time as New York.

Of course, don't share your secrets.py - keep that out of GitHub, Discord or other project-sharing sites.

Connect to WiFi

OK now you have your secrets setup - you can connect to the Internet using the ESP32SPI and the

Requests modules.

First make sure you are running the latest version of Adafruit CircuitPython (https://adafru.it/Amd) for your

board.

Next you'll need to install the necessary libraries to use the hardware--carefully follow the steps to find and

install these libraries from Adafruit's CircuitPython library bundle (https://adafru.it/zdx). Our introduction

guide has a great page on how to install the library bundle (https://adafru.it/ABU) for both express and

non-express boards.

Remember for non-express boards like the, you'll need to manually install the necessary libraries from the

bundle:

adafruit_bus_device

adafruit_esp32_spi

adafruit_requests

neopixel

Before continuing make sure your board's lib folder or root filesystem has the above files copied over.

Next connect to the board's serial REPL (https://adafru.it/Awz) so you are at the CircuitPython >>> prompt.

Into your lib folder. Once that's done, load up the following example using Mu or your favorite editor:

# SPDX-FileCopyrightText: 2019 ladyada for Adafruit Industries # SPDX-License-Identifier: MIT

import board import busio from digitalio import DigitalInOut import adafruit_requests as requests import adafruit_esp32spi.adafruit_esp32spi_socket as socket from adafruit_esp32spi import adafruit_esp32spi

# Get wifi details and more from a secrets.py file try: from secrets import secrets except ImportError: print("WiFi secrets are kept in secrets.py, please add them there!") raise

print("ESP32 SPI webclient test")

TEXT_URL = "http://wifitest.adafruit.com/testwifi/index.html" JSON_URL = "http://api.coindesk.com/v1/bpi/currentprice/USD.json"

# If you are using a board with pre-defined ESP32 Pins: esp32_cs = DigitalInOut(board.ESP_CS) esp32_ready = DigitalInOut(board.ESP_BUSY) esp32_reset = DigitalInOut(board.ESP_RESET)

# If you have an AirLift Shield: # esp32_cs = DigitalInOut(board.D10) # esp32_ready = DigitalInOut(board.D7) # esp32_reset = DigitalInOut(board.D5)

# If you have an AirLift Featherwing or ItsyBitsy Airlift: # esp32_cs = DigitalInOut(board.D13) # esp32_ready = DigitalInOut(board.D11) # esp32_reset = DigitalInOut(board.D12)

# If you have an externally connected ESP32: # NOTE: You may need to change the pins to reflect your wiring # esp32_cs = DigitalInOut(board.D9) # esp32_ready = DigitalInOut(board.D10) # esp32_reset = DigitalInOut(board.D5)

spi = busio.SPI(board.SCK, board.MOSI, board.MISO) esp = adafruit_esp32spi.ESP_SPIcontrol(spi, esp32_cs, esp32_ready, esp32_reset)

requests.set_socket(socket, esp)

if esp.status == adafruit_esp32spi.WL_IDLE_STATUS: print("ESP32 found and in idle mode") print("Firmware vers.", esp.firmware_version) print("MAC addr:", [hex(i) for i in esp.MAC_address])

for ap in esp.scan_networks(): print("\t%s\t\tRSSI: %d" % (str(ap["ssid"], "utf-8"), ap["rssi"]))

print("Connecting to AP...") while not esp.is_connected: try: esp.connect_AP(secrets["ssid"], secrets["password"]) except RuntimeError as e: print("could not connect to AP, retrying: ", e) continue print("Connected to", str(esp.ssid, "utf-8"), "\tRSSI:", esp.rssi) print("My IP address is", esp.pretty_ip(esp.ip_address)) print( "IP lookup adafruit.com: %s" % esp.pretty_ip(esp.get_host_by_name("adafruit.com")) ) print("Ping google.com: %d ms" % esp.ping("google.com"))

# esp._debug = True print("Fetching text from", TEXT_URL) r = requests.get(TEXT_URL) print("-" * 40) print(r.text) print("-" * 40) r.close()

print() print("Fetching json from", JSON_URL) r = requests.get(JSON_URL) print("-" * 40) print(r.json()) print("-" * 40) r.close()

print("Done!")

And save it to your board, with the name code.py .

 You may need to change the esp32_cs, esp32_ready and esp32_reset pins in the code to match

your hardware's pinout.

Then go down to this line

esp.connect_AP(b'MY_SSID_NAME', b'MY_SSID_PASSWORD')

and change MY_SSID_NAME and MY_SSID_PASSWORD to your access point name and password,

keeping them within the '' quotes. (This example doesn't use the secrets' file, but its also very stand-alone

so if other things seem to not work you can always re-load this. You should get something like the

following:

In order, the example code...

Initializes the ESP32 over SPI using the SPI port and 3 control pins:

esp32_cs = DigitalInOut(board.ESP_CS) esp32_ready = DigitalInOut(board.ESP_BUSY) esp32_reset = DigitalInOut(board.ESP_RESET)

spi = busio.SPI(board.SCK, board.MOSI, board.MISO) esp = adafruit_esp32spi.ESP_SPIcontrol(spi, esp32_cs, esp32_ready, esp32_reset)

Tells our requests library the type of socket we're using (socket type varies by connectivity type - we'll be

using the adafruit_esp32spi_socket for this example). We'll also set the interface to an esp object. This is a

little bit of a hack, but it lets us use requests like CPython does.

requests.set_socket(socket, esp)

Verifies an ESP32 is found, checks the firmware and MAC address

if esp.status == adafruit_esp32spi.WL_IDLE_STATUS: print("ESP32 found and in idle mode") print("Firmware vers.", esp.firmware_version) print("MAC addr:", [hex(i) for i in esp.MAC_address])

Performs a scan of all access points it can see and prints out the name and signal strength:

for ap in esp.scan_networks(): print("\t%s\t\tRSSI: %d" % (str(ap['ssid'], 'utf-8'), ap['rssi']))

Connects to the AP we've defined here, then prints out the local IP address, attempts to do a domain

name lookup and ping google.com to check network connectivity (note sometimes the ping fails or takes

a while, this isn't a big deal)

print("Connecting to AP...") esp.connect_AP(b'MY_SSID_NAME', b'MY_SSID_PASSWORD') print("Connected to", str(esp.ssid, 'utf-8'), "\tRSSI:", esp.rssi) print("My IP address is", esp.pretty_ip(esp.ip_address)) print("IP lookup adafruit.com: %s" % esp.pretty_ip(esp.get_host_by_name("adafruit.com"))) print("Ping google.com: %d ms" % esp.ping("google.com"))

OK now we're getting to the really interesting part. With a SAMD51 or other large-RAM (well, over 32 KB)

device, we can do a lot of neat tricks. Like for example we can implement an interface a lot like

requests (https://adafru.it/E9o) - which makes getting data

really really easy

To read in all the text from a web URL call requests.get - you can pass in https URLs for SSL connectivity

TEXT_URL = "http://wifitest.adafruit.com/testwifi/index.html" print("Fetching text from", TEXT_URL) r = requests.get(TEXT_URL) print('-'*40) print(r.text) print('-'*40) r.close()

Or, if the data is in structured JSON, you can get the json pre-parsed into a Python dictionary that can be

easily queried or traversed. (Again, only for nRF52840, M4 and other high-RAM boards)

JSON_URL = "http://api.coindesk.com/v1/bpi/currentprice/USD.json" print("Fetching json from", JSON_URL) r = requests.get(JSON_URL) print('-'*40) print(r.json()) print('-'*40) r.close()

Requests

We've written a requests-like (https://adafru.it/Kpa) library for web interfacing

named Adafruit_CircuitPython_Requests (https://adafru.it/FpW). This library allows you to send HTTP/1.1

requests without "crafting" them and provides helpful methods for parsing the response from the server.

Here's an example of using Requests to perform GET and POST requests to a server.

# SPDX-FileCopyrightText: 2021 ladyada for Adafruit Industries # SPDX-License-Identifier: MIT

# adafruit_requests usage with an esp32spi_socket import board import busio from digitalio import DigitalInOut import adafruit_esp32spi.adafruit_esp32spi_socket as socket

from adafruit_esp32spi import adafruit_esp32spi import adafruit_requests as requests

# Add a secrets.py to your filesystem that has a dictionary called secrets with "ssid" and # "password" keys with your WiFi credentials. DO NOT share that file or commit it into Git or other # source control. # pylint: disable=no-name-in-module,wrong-import-order try: from secrets import secrets except ImportError: print("WiFi secrets are kept in secrets.py, please add them there!") raise

# If you are using a board with pre-defined ESP32 Pins: esp32_cs = DigitalInOut(board.ESP_CS) esp32_ready = DigitalInOut(board.ESP_BUSY) esp32_reset = DigitalInOut(board.ESP_RESET)

# If you have an externally connected ESP32: # esp32_cs = DigitalInOut(board.D9) # esp32_ready = DigitalInOut(board.D10) # esp32_reset = DigitalInOut(board.D5)

spi = busio.SPI(board.SCK, board.MOSI, board.MISO) esp = adafruit_esp32spi.ESP_SPIcontrol(spi, esp32_cs, esp32_ready, esp32_reset)

print("Connecting to AP...") while not esp.is_connected: try: esp.connect_AP(secrets["ssid"], secrets["password"]) except RuntimeError as e: print("could not connect to AP, retrying: ", e) continue print("Connected to", str(esp.ssid, "utf-8"), "\tRSSI:", esp.rssi)

# Initialize a requests object with a socket and esp32spi interface socket.set_interface(esp) requests.set_socket(socket, esp)

TEXT_URL = "http://wifitest.adafruit.com/testwifi/index.html" JSON_GET_URL = "http://httpbin.org/get" JSON_POST_URL = "http://httpbin.org/post"

print("Fetching text from %s" % TEXT_URL) response = requests.get(TEXT_URL) print("-" * 40)

print("Text Response: ", response.text) print("-" * 40) response.close()

print("Fetching JSON data from %s" % JSON_GET_URL) response = requests.get(JSON_GET_URL) print("-" * 40)

print("JSON Response: ", response.json()) print("-" * 40) response.close()

data = "31F" print("POSTing data to {0}: {1}".format(JSON_POST_URL, data)) response = requests.post(JSON_POST_URL, data=data) print("-" * 40)

json_resp = response.json() # Parse out the 'data' key from json_resp dict. print("Data received from server:", json_resp["data"]) print("-" * 40) response.close()

json_data = {"Date": "July 25, 2019"} print("POSTing data to {0}: {1}".format(JSON_POST_URL, json_data)) response = requests.post(JSON_POST_URL, json=json_data) print("-" * 40)

json_resp = response.json() # Parse out the 'json' key from json_resp dict. print("JSON Data received from server:", json_resp["json"]) print("-" * 40) response.close()

The code first sets up the ESP32SPI interface. Then, it initializes a request object using an ESP32 socket

and the esp object.

import board import busio from digitalio import DigitalInOut import adafruit_esp32spi.adafruit_esp32spi_socket as socket from adafruit_esp32spi import adafruit_esp32spi import adafruit_requests as requests

# If you have an externally connected ESP32: esp32_cs = DigitalInOut(board.D9) esp32_ready = DigitalInOut(board.D10) esp32_reset = DigitalInOut(board.D5)

spi = busio.SPI(board.SCK, board.MOSI, board.MISO) esp = adafruit_esp32spi.ESP_SPIcontrol(spi, esp32_cs, esp32_ready, esp32_reset)

print("Connecting to AP...") while not esp.is_connected: try: esp.connect_AP(b'MY_SSID_NAME', b'MY_SSID_PASSWORD') except RuntimeError as e: print("could not connect to AP, retrying: ",e) continue print("Connected to", str(esp.ssid, 'utf-8'), "\tRSSI:", esp.rssi)

# Initialize a requests object with a socket and esp32spi interface requests.set_socket(socket, esp)

Make sure to set the ESP32 pinout to match your AirLift breakout's connection:

esp32_cs = DigitalInOut(board.D9) esp32_ready = DigitalInOut(board.D10) esp32_reset = DigitalInOut(board.D5)

HTTP GET with Requests

The code makes a HTTP GET request to Adafruit's WiFi testing website

- http://wifitest.adafruit.com/testwifi/index.html (https://adafru.it/FpZ).

To do this, we'll pass the URL into requests.get() . We're also going to save the response

from

the server

into a variable named response .

While we requested data from the server, we'd what the server responded with. Since we already saved

the server's response , we can read it back. Luckily for us, requests automatically decodes the server's

response into human-readable text, you can read it back by calling response.text .

Lastly, we'll perform a bit of cleanup by calling response.close() . This closes, deletes, and collect's the

response's data.

print("Fetching text from %s"%TEXT_URL) response = requests.get(TEXT_URL) print('-'*40)

print("Text Response: ", response.text) print('-'*40) response.close()

While some servers respond with text, some respond with json-formatted data consisting of attribute–

value pairs.

CircuitPython_Requests can convert a JSON-formatted response from a server into a CPython dict.

object.

We can also fetch and parse json data. We'll send a HTTP get to a url we know returns a json-formatted

response (instead of text data).

Then, the code calls response.json() to convert the response to a CPython dict .

print("Fetching JSON data from %s"%JSON_GET_URL) response = requests.get(JSON_GET_URL) print('-'*40)

print("JSON Response: ", response.json()) print('-'*40) response.close()

HTTP POST with Requests

Requests can also POST data to a server by calling the requests.post method, passing it a data value.

data = '31F' print("POSTing data to {0}: {1}".format(JSON_POST_URL, data)) response = requests.post(JSON_POST_URL, data=data) print('-'*40)

json_resp = response.json() # Parse out the 'data' key from json_resp dict. print("Data received from server:", json_resp['data']) print('-'*40) response.close()

You can also post json-formatted data to a server by passing json data into the requests.post method.

json_data = {"Date" : "July 25, 2019"} print("POSTing data to {0}: {1}".format(JSON_POST_URL, json_data)) response = requests.post(JSON_POST_URL, json=json_data) print('-'*40)

json_resp = response.json() # Parse out the 'json' key from json_resp dict. print("JSON Data received from server:", json_resp['json']) print('-'*40) response.close()

Advanced Requests Usage

Want to send custom HTTP headers, parse the response as raw bytes, or handle a response's http status

code in your CircuitPython code?

We've written an example to show advanced usage of the requests module below.

# SPDX-FileCopyrightText: 2021 ladyada for Adafruit Industries # SPDX-License-Identifier: MIT

import board import busio from digitalio import DigitalInOut import adafruit_esp32spi.adafruit_esp32spi_socket as socket from adafruit_esp32spi import adafruit_esp32spi import adafruit_requests as requests

# Add a secrets.py to your filesystem that has a dictionary called secrets with "ssid" and # "password" keys with your WiFi credentials. DO NOT share that file or commit it into Git or other # source control. # pylint: disable=no-name-in-module,wrong-import-order try: from secrets import secrets except ImportError: print("WiFi secrets are kept in secrets.py, please add them there!") raise

# If you are using a board with pre-defined ESP32 Pins: esp32_cs = DigitalInOut(board.ESP_CS) esp32_ready = DigitalInOut(board.ESP_BUSY) esp32_reset = DigitalInOut(board.ESP_RESET)

# If you have an externally connected ESP32: # esp32_cs = DigitalInOut(board.D9) # esp32_ready = DigitalInOut(board.D10) # esp32_reset = DigitalInOut(board.D5)

spi = busio.SPI(board.SCK, board.MOSI, board.MISO) esp = adafruit_esp32spi.ESP_SPIcontrol(spi, esp32_cs, esp32_ready, esp32_reset)

print("Connecting to AP...") while not esp.is_connected: try: esp.connect_AP(secrets["ssid"], secrets["password"]) except RuntimeError as e: print("could not connect to AP, retrying: ", e) continue print("Connected to", str(esp.ssid, "utf-8"), "\tRSSI:", esp.rssi)

# Initialize a requests object with a socket and esp32spi interface

socket.set_interface(esp) requests.set_socket(socket, esp)

JSON_GET_URL = "http://httpbin.org/get"

# Define a custom header as a dict. headers = {"user-agent": "blinka/1.0.0"}

print("Fetching JSON data from %s..." % JSON_GET_URL) response = requests.get(JSON_GET_URL, headers=headers) print("-" * 60)

json_data = response.json() headers = json_data["headers"] print("Response's Custom User-Agent Header: {0}".format(headers["User-Agent"])) print("-" * 60)

# Read Response's HTTP status code print("Response HTTP Status Code: ", response.status_code) print("-" * 60)

# Close, delete and collect the response data response.close()

WiFi Manager

That simpletest example works but its a little finicky - you need to constantly check WiFi status and have

many loops to manage connections and disconnections. For more advanced uses, we recommend using

the WiFiManager object. It will wrap the connection/status/requests loop for you - reconnecting if WiFi

drops, resetting the ESP32 if it gets into a bad state, etc.

Here's a more advanced example that shows the WiFi manager and also how to POST data with some

extra headers:

# SPDX-FileCopyrightText: 2019 ladyada for Adafruit Industries # SPDX-License-Identifier: MIT

import time import board import busio from digitalio import DigitalInOut import neopixel from adafruit_esp32spi import adafruit_esp32spi from adafruit_esp32spi import adafruit_esp32spi_wifimanager

print("ESP32 SPI webclient test")

# Get wifi details and more from a secrets.py file try: from secrets import secrets except ImportError: print("WiFi secrets are kept in secrets.py, please add them there!") raise

# If you are using a board with pre-defined ESP32 Pins: esp32_cs = DigitalInOut(board.ESP_CS) esp32_ready = DigitalInOut(board.ESP_BUSY) esp32_reset = DigitalInOut(board.ESP_RESET)

# If you have an externally connected ESP32: # esp32_cs = DigitalInOut(board.D9)

# esp32_ready = DigitalInOut(board.D10) # esp32_reset = DigitalInOut(board.D5)

spi = busio.SPI(board.SCK, board.MOSI, board.MISO) esp = adafruit_esp32spi.ESP_SPIcontrol(spi, esp32_cs, esp32_ready, esp32_reset) """Use below for Most Boards""" status_light = neopixel.NeoPixel( board.NEOPIXEL, 1, brightness=0.2 ) # Uncomment for Most Boards """Uncomment below for ItsyBitsy M4""" # status_light = dotstar.DotStar(board.APA102_SCK, board.APA102_MOSI, 1, brightness=0.2) # Uncomment below for an externally defined RGB LED # import adafruit_rgbled # from adafruit_esp32spi import PWMOut # RED_LED = PWMOut.PWMOut(esp, 26) # GREEN_LED = PWMOut.PWMOut(esp, 27) # BLUE_LED = PWMOut.PWMOut(esp, 25) # status_light = adafruit_rgbled.RGBLED(RED_LED, BLUE_LED, GREEN_LED) wifi = adafruit_esp32spi_wifimanager.ESPSPI_WiFiManager(esp, secrets, status_light)

counter = 0

while True: try: print("Posting data...", end="") data = counter feed = "test" payload = {"value": data} response = wifi.post( "https://io.adafruit.com/api/v2/" + secrets["aio_username"] + "/feeds/" + feed + "/data", json=payload, headers={"X-AIO-KEY": secrets["aio_key"]}, ) print(response.json()) response.close() counter = counter + 1 print("OK") except (ValueError, RuntimeError) as e: print("Failed to get data, retrying\n", e) wifi.reset() continue response = None time.sleep(15)

You'll note here we use a secrets.py file to manage our SSID info. The wifimanager is given the ESP32

object, secrets and a neopixel for status indication.

Note, you'll need to add a some additional information to your secrets file so that the code can query the

Adafruit IO API:

aio_username

aio_key

You can go to your adafruit.io View AIO Key link to get those two values and add them to the secrets file,

which will now look something like this:

# This file is where you keep secret settings, passwords, and tokens! # If you put them in the code you risk committing that info or sharing it

secrets = { 'ssid' : '_your_ssid_', 'password' : '_your_wifi_password_', 'timezone' : "America/Los_Angeles", # http://worldtimeapi.org/timezones 'aio_username' : '_your_aio_username_', 'aio_key' : '_your_aio_key_', }

Next, set up an Adafruit IO feed named test

If you do not know how to set up a feed, follow this page and come back when you've set up a feed

named test . (https://adafru.it/f5k)

We can then have a simple loop for posting data to Adafruit IO without having to deal with connecting or

initializing the hardware!

Take a look at your test feed on Adafruit.io and you'll see the value increase each time the CircuitPython

board posts data to it!

CircuitPython BLE CircuitPython BLE UART Example

It's easy to use Adafruit AirLift ESP32 co-processor boards for Bluetooth Low Energy (BLE) with

CircuitPython. When you reset the ESP32, you can put it in WiFi mode (the default), or in BLE mode; you

cannot use both modes simultaenously.

Here's a simple example of using BLE to connect CircuitPython with the Bluefruit Connect app. Use

CircuitPython 6.0.0 or later.

Note: Don't confuse the ESP32 with the ESP32-S2, which is a different module with a similar name. The

ESP32-S2 does not support BLE.

 Currently the AirLift support for CircuitPython only provides BLE peripheral support. BLE central is

under development. So you cannot connect to BLE devices like Heart Rate monitors, etc., but you can

act as a BLE peripheral yourself.

Adafruit AirLift ESP32 Shield Wiring

If you have an Adafruit AirLift ESP32 Shield, you will need to solder three jumpers closed on the bottom

side of the board to enable BLE. The rest of the ESP32 pins you need are already jumpered to certain

shield pins.

Update the AirLift Firmware

You will need to update the AirLift's firmware to at least version 1.7.1. Previous versions of the AirLift

firmware do not support BLE.

Follow the instructions in the guide below, and come back to this page when you've upgraded the AirLift's

firmware:

https://adafru.it/RdC

 Ensure the AirLift firmware is version 1.7.1 or higher for BLE to work.

Install CircuitPython Libraries

Make sure you are running the latest version of Adafruit CircuitPython (https://adafru.it/Amd) for your

board; you'll need 6.0.0 or later.

Next you'll need to install the necessary libraries to use the hardware and BLE. Carefully follow the steps

to find and install these libraries from Adafruit's CircuitPython library bundle (https://adafru.it/uap). Our

CircuitPython starter guide has a great page on how to use the library bundle (https://adafru.it/ABU).

Install these libraries from the bundle:

adafruit_airlift

adafruit_ble

https://adafru.it/RdC

Before continuing make sure your board's lib folder or root filesystem has the adafruit_airlift and

adafruit_ble folders copied over.

Install the Adafruit Bluefruit LE Connect App

The Adafruit Bluefruit LE Connect iOS and Android apps allow you to connect to BLE peripherals that

provide a over-the-air "UART" service. Follow the instructions in the Bluefruit LE Connect

Guide (https://adafru.it/Eg5) to download and install the app on your phone or tablet.

Copy and Adjust the Example Program

Copy the program below to the file code.py on CIRCUITPY on your board.

TAKE NOTE: Adjust the program as needed to suit the AirLift board you have. Comment and

uncomment lines 12-39 below as necessary.

import board

from adafruit_ble import BLERadio from adafruit_ble.advertising.standard import ProvideServicesAdvertisement from adafruit_ble.services.nordic import UARTService

from adafruit_airlift.esp32 import ESP32

# If you are using a Metro M4 Airlift Lite, PyPortal, # or MatrixPortal, you can use the default pin settings. # Leave this DEFAULT line uncommented. esp32 = ESP32() # DEFAULT

# If you are using CircuitPython 6.0.0 or earlier, # on PyPortal and PyPortal Titano only, use the pin settings # below. Comment out the DEFAULT line above and uncomment # the line below. For CircuitPython 6.1.0, the pin names # have changed for these boards, and the DEFAULT line # above is correct. # esp32 = ESP32(tx=board.TX, rx=board.RX)

# If you are using an AirLift FeatherWing or AirLift Bitsy Add-On, # use the pin settings below. Comment out the DEFAULT line above # and uncomment the lines below. # If you are using an AirLift Breakout, check that these # choices match the wiring to your microcontroller board, # or change them as appropriate. # esp32 = ESP32( # reset=board.D12, # gpio0=board.D10, # busy=board.D11, # chip_select=board.D13, # tx=board.TX, # rx=board.RX, # )

# If you are using an AirLift Shield, # use the pin settings below. Comment out the DEFAULT line above # and uncomment the lines below. # esp32 = ESP32( # reset=board.D5, # gpio0=board.D6, # busy=board.D7, # chip_select=board.D10, # tx=board.TX,

# tx=board.TX, # rx=board.RX, # )

adapter = esp32.start_bluetooth()

ble = BLERadio(adapter) uart = UARTService() advertisement = ProvideServicesAdvertisement(uart)

while True: ble.start_advertising(advertisement) print("waiting to connect") while not ble.connected: pass print("connected: trying to read input") while ble.connected: # Returns b'' if nothing was read. one_byte = uart.read(1) if one_byte: print(one_byte) uart.write(one_byte)

Talk to the AirLift via the Bluefruit LE Connect App

Start the Bluefruit LE Connect App on your phone or tablet. You should see a CIRCUITPY device available

to connect to. Tap the Connect button (1):

You'll then see a list of Bluefruit Connect functions ("modules"). Choose the UART module (2):

On the UART module page, you can type a string and press Send (3). You'll see that string entered, and

then see it echoed back (echoing is in gray).

Arduino WiFi

You can use an AirLift with Arduino. Unlike CircuitPython, it work work with just about any Arduino board,

even a classic Arduino UNO. However, if you want to use libraries like Adafruit IO Arduino, ArduinoJSON,

or add sensors and SD card, you'll really want an ATSAMD21 (Cortex M0) or ATSAMD51 (Cortex M4), both

of which have

plenty

or RAM.

Library Install

We're using a variant of the Arduino WiFiNINA library, which is amazing and written by the Arduino team!

The official WiFi101 library won't work because it doesn't support the ability to change the pins .

So! We made a fork that you can install.

Click here to download the library:

https://adafru.it/Evm

Within the Arduino IDE, select Sketch->Include Library -> Add .ZIP library...

And select the zip you just downloaded.

First Test

OK now you have it wired and library installed, time to test it out!

Lets start by scanning the local networks. Load up the ScanNetworks example

https://adafru.it/Evm

(https://adafru.it/EVu)

At the top you'll see a section where the GPIO pins are defined

(https://adafru.it/EVv)

If you don't see this, you may have the wrong WiFiNINA library installed. Uninstall it and re-install the

Adafruit one as above.

Arduino Microcontroller Pin Definition

Next, you'll need to need to modify the pin definition above for the AirLift Shield. Replace the

configuration in the sketch with the pinouts below:

#define SPIWIFI SPI // The SPI port #define SPIWIFI_SS 10 // Chip select pin #define ESP32_RESETN 5 // Reset pin #define SPIWIFI_ACK 7 // a.k.a BUSY or READY pin #define ESP32_GPIO0 6

Compile and upload to your board wired up to the AirLift

(https://adafru.it/EVw)

If you don't even get the MAC address printed out, check your wiring.

If you get the MAC address but cannot scan any networks, check your power supply. You need a solid 3-

5VDC into Vin in order for the ESP32 not to brown out.

WiFi Connection Test

Now that you have your wiring checked, time to connect to the Internet!

Open up the WiFiWebClient example

(https://adafru.it/EVx)

Open up the secondary tab, arduino_secrets.h. This is where you will store private data like the

SSID/password to your network.

(https://adafru.it/EVy)

You must change these string values before updating to your board!

After you've set it correctly, upload and check the serial monitor. You should see the following. If not, go

back, check wiring, power and your SSID/password

(https://adafru.it/EVz)

Secure Connection Example

Many servers today do not allow non-SSL connectivity. Lucky for you the ESP32 has a great TLS/SSL stack

so you can have that all taken care of for you. Here's an example of a secure WiFi connection:

(https://adafru.it/EVA)

Note we use WiFiSSLClient client; instead of WiFiClient client; to require an SSL connection!

(https://adafru.it/EVB)

JSON Parsing Example

This example is a little more advanced - many sites will have API's that give you JSON data. We'll

use ArduinoJSON (https://adafru.it/Evn) to convert that to a format we can use and then display that data

on the serial port (which can then be re-directed to a display of some sort)

First up, use the Library manager to install ArduinoJSON (https://adafru.it/Evo).

Then load the example JSONdemo

(https://adafru.it/EVC)

By default it will connect to to the Twitter banner image API, parse the username and followers and display

them.

(https://adafru.it/EVD)

Adapting Other Examples

Once you've got it connecting to the Internet you can check out the other examples. The only change

you'll want to make is at the top of the sketches, add:

#define SPIWIFI SPI // The SPI port #define SPIWIFI_SS 10 // Chip select pin #define ESP32_RESETN 5 // Reset pin #define SPIWIFI_ACK 7 // a.k.a BUSY or READY pin #define ESP32_GPIO0 6

And then before you check the status() of the module, call the function WiFi.setPins(SPIWIFI_SS,

SPIWIFI_ACK, ESP32_RESETN, ESP32_GPIO0, &SPIWIFI); like so:

// check for the WiFi module: WiFi.setPins(SPIWIFI_SS, SPIWIFI_ACK, ESP32_RESETN, ESP32_GPIO0, &SPIWIFI); while (WiFi.status() == WL_NO_MODULE) { Serial.println("Communication with WiFi module failed!"); // don't continue delay(1000); }

Upgrade External ESP32 Airlift Firmware

 To support BLE on the ESP32 AirLift, you'll need NINA_W102-1.7.1.bin or later.

External AirLift FeatherWing, Shield, or ItsyWing

External AirLift boards have three optional ESP32 control pins which are not connected by default:

ESPGPIO0

ESPRX

ESPTX

Make sure to solder each of these pads together. You will not

be able to upload firmware to your ESP32 if they are not

connected.

Upload Serial Passthrough code for Feather or ItsyBitsy

First, back up any code and files you have on your CIRCUITPY drive . It will be overwritten by the code

you're going to upload to your board. You should not end up losing any files on the QSPI flash, but it's a

good idea to back them up anyways.

 This section is only for an AirLift FeatherWing with a Feather M4, or an AirLift BitsyWing with an

ItsyBitsy M4. If you are using a different hardware combination - scroll down to the "External AirLift

Breakout" section.

Download the UF2 for your board to your Desktop.

https://adafru.it/OYF

https://adafru.it/PTE

https://adafru.it/IEK

Find the reset button on your board. It's a small, black button, and on most of the boards, it will be the only

button available.

Tap this button twice to enter the bootloader. If it doesn't work on the first try, don't be discouraged. The

rhythm of the taps needs to be correct and sometimes it takes a few tries.

Once successful, the RGB LED on the board will flash red and then stay green. A new drive will show up

on your computer. The drive will be called boardnameBOOT where boardname is a reference to your

specific board. For example, a Feather will have FEATHERBOOT and a Trinket will

have TRINKETBOOT etc. Going forward we'll just call the boot drive BOOT

The board is now in bootloader mode. Now find the UF2 file you downloaded. Drag that file to the BOOT

drive on your computer in your operating system file manager/finder.

https://adafru.it/OYF

https://adafru.it/PTE

https://adafru.it/IEK

The lights should flash again, BOOT will disappear. Your board should re-enumerate USB and appear as a

COM or Serial port on your computer. Make a note of the serial port by checking the Device Manager

(Windows) or typing ls /dev/cu* or /dev/tty* (Mac or Linux) in a terminal.

If your board is listed in the terminal, proceed to the Uploading nina-fw with esptool section of this guide.

External AirLift Breakout

You'll be turning your Arduino board into a USB to Serial converter. To do this, you'll need a special

Arduino sketch named SerialESPPassthrough.ino and an Arduino-compatible board with Native USB

support such as the Adafruit Metro M4.

You will also need to make the following connections between the board and the AirLift Breakout:

Board Pin 12 to ESP32_ResetN

Board Pin 10 to ESP32 GPIO0

Board TX to RXI

Board RX to TX0

Click

Download: Project ZIP

to download the code below.

/* SerialNINAPassthrough - Use esptool to flash the ESP32 module For use with PyPortal, Metro M4 WiFi...

This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */

#include <Adafruit_NeoPixel.h>

unsigned long baud = 115200;

#if defined(ADAFRUIT_FEATHER_M4_EXPRESS) || \ defined(ADAFRUIT_FEATHER_M0_EXPRESS) || \ defined(ARDUINO_AVR_FEATHER32U4) || \ defined(ARDUINO_NRF52840_FEATHER) || \ defined(ADAFRUIT_ITSYBITSY_M0) || \ defined(ADAFRUIT_ITSYBITSY_M4_EXPRESS) || \ defined(ARDUINO_AVR_ITSYBITSY32U4_3V) || \ defined(ARDUINO_NRF52_ITSYBITSY) // Configure the pins used for the ESP32 connection #define SerialESP32 Serial1 #define SPIWIFI SPI // The SPI port #define SPIWIFI_SS 13 // Chip select pin #define ESP32_RESETN 12 // Reset pin #define SPIWIFI_ACK 11 // a.k.a BUSY or READY pin #define ESP32_GPIO0 10 #define NEOPIXEL_PIN 8 #elif defined(ARDUINO_AVR_FEATHER328P) #define SerialESP32 Serial1 #define SPIWIFI SPI // The SPI port #define SPIWIFI_SS 4 // Chip select pin #define ESP32_RESETN 3 // Reset pin #define SPIWIFI_ACK 2 // a.k.a BUSY or READY pin #define ESP32_GPIO0 -1 #define NEOPIXEL_PIN 8 #elif defined(TEENSYDUINO) #define SerialESP32 Serial1 #define SPIWIFI SPI // The SPI port #define SPIWIFI_SS 5 // Chip select pin #define ESP32_RESETN 6 // Reset pin #define SPIWIFI_ACK 9 // a.k.a BUSY or READY pin #define ESP32_GPIO0 -1 #define NEOPIXEL_PIN 8 #elif defined(ARDUINO_NRF52832_FEATHER ) #define SerialESP32 Serial1 #define SPIWIFI SPI // The SPI port #define SPIWIFI_SS 16 // Chip select pin #define ESP32_RESETN 15 // Reset pin #define SPIWIFI_ACK 7 // a.k.a BUSY or READY pin #define ESP32_GPIO0 -1 #define NEOPIXEL_PIN 8 #elif !defined(SPIWIFI_SS) // if the wifi definition isnt in the board variant // Don't change the names of these #define's! they match the variant ones #define SerialESP32 Serial1 #define SPIWIFI SPI #define SPIWIFI_SS 10 // Chip select pin #define SPIWIFI_ACK 7 // a.k.a BUSY or READY pin #define ESP32_RESETN 5 // Reset pin #define ESP32_GPIO0 -1 // Not connected #define NEOPIXEL_PIN 8 #endif

#if defined(ADAFRUIT_PYPORTAL) #define PIN_NEOPIXEL 2 #elif defined(ADAFRUIT_METRO_M4_AIRLIFT_LITE) #define PIN_NEOPIXEL 40 #endif

Adafruit_NeoPixel pixel = Adafruit_NeoPixel(1, PIN_NEOPIXEL, NEO_GRB + NEO_KHZ800);

void setup() { Serial.begin(baud); pixel.begin(); pixel.setPixelColor(0, 10, 10, 10); pixel.show();

while (!Serial); pixel.setPixelColor(0, 50, 50, 50); pixel.show();

delay(100); SerialESP32.begin(baud);

pinMode(SPIWIFI_SS, OUTPUT); pinMode(ESP32_GPIO0, OUTPUT); pinMode(ESP32_RESETN, OUTPUT);

// manually put the ESP32 in upload mode digitalWrite(ESP32_GPIO0, LOW);

digitalWrite(ESP32_RESETN, LOW); delay(100); digitalWrite(ESP32_RESETN, HIGH); pixel.setPixelColor(0, 20, 20, 0); pixel.show(); delay(100); }

void loop() { while (Serial.available()) { pixel.setPixelColor(0, 10, 0, 0); pixel.show(); SerialESP32.write(Serial.read()); }

while (SerialESP32.available()) { pixel.setPixelColor(0, 0, 0, 10); pixel.show(); Serial.write(SerialESP32.read()); } }

Code Usage

Unzip the file, and open the SerialESPPassthrough.ino file in the Arduino IDE.

If you're using the AirLift FeatherWing, AirLift Shield or AirLift Bitsy Add-On, use the PassThrough UF2

instructions above

If you have an AirLift Breakout (or are manually wiring up any of the boards above), change the following

pin definitions in the sketch to match your wiring:

#elif !defined(SPIWIFI_SS) // if the wifi definition isnt in the board variant // Don't change the names of these #define's! they match the variant ones #define SerialESP32 Serial1 #define SPIWIFI SPI #define SPIWIFI_SS 10 // Chip select pin #define SPIWIFI_ACK 7 // a.k.a BUSY or READY pin #define ESP32_RESETN 5 // Reset pin #define ESP32_GPIO0 -1 // Not connected #define NEOPIXEL_PIN 8 #endif

Using the Arduino IDE, upload the code to your board (

Sketch->Upload

).

After uploading, the board should enumerate USB and appear as a COM or Serial port on your computer.

Make a note of the serial port by checking the Device Manager (Windows) or typing in ls

/dev/cu* or /dev/tty* (Mac or Linux) in a terminal

 This guide assumes you have Python3 installed. If you have not installed it, navigate to the Python

downloads page (https://www.python.org/downloads) and install the latest release.

Install esptool.py

Esptool is an application which can communicate with the ROM bootloader (https://adafru.it/LKe) in

Espressif chips.

To install esptool, run the following in your terminal :

pip3 install esptool

Burning nina-fw with esptool

Click the link below to download the latest nina-fw .bin file. Unzip it and save the .bin file to your desktop .

https://adafru.it/G3D

If you're using macOS or Linux - run the following command, replacing /dev/ttyACM0 with the serial port of

your board and NINA_W102-1.6.0 with the binary file you're flashing to the ESP32.

esptool.py --port /dev/ttyACM0 --before no_reset --baud 115200 write_flash 0 NINA_W102-1.6.0.bin

If you're using Windows - run the following command, replacing COM7 with the serial port of your board

and NINA_W102-1.6.0 with the binary file you're flashing to the ESP32

esptool.py --port COM7 --before no_reset --baud 115200 write_flash 0 NINA_W102-1.6.0.bin

The command should detect the ESP32 and will take a minute or two to upload the firmware.

If ESPTool doesn't detect the ESP32

, make sure you've uploaded the correct .UF2 file to the bootloader

and are using the correct serial port.

https://adafru.it/G3D

Once the firmware is fully uploaded, the ESP32 will reset.

Verifying the Upgraded Firmware Version

To verify everything is working correctly, we'll load up either an Arduino sketch or CircuitPython code. At

this point, you must desolder the connections between the Optional ESP32 control pins you made

earlier using a solder sucker (https://adafru.it/FWk) or a bit of solder wick (https://adafru.it/yrC).

Arduino

If you were previously using your ESP32 with Arduino, you should load up an Arduino sketch to verify

everything is working properly and the version of the nina-fw correlates with the version the sketch reads.

Open up File->Examples->WiFiNINA->ScanNetworks and upload the sketch. Then, open the Serial

Monitor. You should see the firmware version printed out to the serial monitor.

CircuitPython

If you were previously using your ESP32 project with CircuitPython , you'll need to first reinstall

CircuitPython firmware (UF2) for your board. The QSPI flash should have retained its contents. If you don't

see anything on the CIRCUITPY volume, copy files from the backup you made earlier to CIRCUITPY .

To verify the new ESP32 WiFi firmware version is correct, follow the Connect to WiFi step in this

guide (https://adafru.it/Eao) and come back here when you've successfully ran the code. The REPL output

should display the firmware version you flashed.

Downloads

Files

ESP32 WROOM32 Datasheet (https://adafru.it/EVE)

EagleCAD files on GitHub (https://adafru.it/F6p)

Fritzing object in Adafruit Fritzing Library (https://adafru.it/F6q)

Schematic

Fab Print

Adafruit ESP32 WiFi User manual

Specifications and Main Features

Frequently Asked Questions

User Manual