Classic SPI Pins:
SCK - SPI Clock from your microcontroller, level shifted so can be 3-5V logic
MISO - SPI Data
from
the AirLift to the microcontroller, this is 3.3V logic out, can be read by 3-5V
logic. This is tri-stated when not selected, so you can share the SPI bus with other devices.
MOSI- SPI Data
to
the AirLift
from
the microcontroller, level shifted so can be 3-5V logic
ESPCS - SPI Chip Select from the microcontroller to start sending commands to the AirLift, level
shifted so can be 3-5V logic
Required Control Pins:
ESPBUSY - 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 pin
must
be connected.
ESPRST- 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:
ESPGPIO0 - 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. It's
not required for WiFi, but you'll need to connect it to use BLE mode. Solder the pad on the bottom of
the FeatherWing to connect it.
ESPRX & ESPTX - 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 FeatherWing to use these pins.
RGB LED
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).