Garmin V4 LED User Manual
LIDAR-LITE V4 LED
DRAFT
OPERATION
MANUAL AND
TECHNICAL SPECIFICATIONS
Specifications
Specification Measurement
Unit dimensions (L × W × H)
NOTE: Measurements do not
include an attached connector.
Weight 14.6 g (0.5 oz.)
Operating temperature -20 to 60°C (-4 to 140°F)
Storage temperature -40 to 85°C (-40 to 185°F)
Power (operating voltage) 4.75 to 5.25 Vdc
Current consumption 2 mA idle
Input voltage (VIN) 3.3 V Max
Range 5 cm (1.97 in.) to 10 m (32.8 ft.)
Resolution 1 cm (0.4 in.)
Beam divergence 4.77 degrees
LED wavelength 940 nm
Optical aperture 14.9 mm
Update rate I2C: Greater than 200 Hz typical
Interface I2C or ANT
Measurement repeatability
NOTE: As measured indoors to a
90% reflective target; 1 cm is
equivalent to 1 standard deviation.
Measurements were obtained
using high accuracy mode.
52.2 x 24 x 21.2 mm (2.1 x 0.9 x
0.8 in.)
85 mA during an acquisition
ANT: Up to 200 Hz to a 90%
reflective target indoors at 2 m in
normal operating mode
®
Configurable for SPI with user
applications
± 1 cm to 2 m
± 2 cm to 4 m
± 5 cm to 10 m
52.17 mm (2.05 in.)
44.98 mm (1.77 in.)
10.6 mm (0.42 in.)
24.03 mm (0.95 in.)
1 mm (0.04 in.)
18 mm (0.71 in.)
21.35 mm (0.84 in.)
21.2 mm (0.83 in.)
Mounting Options
Cable tie
Double-sided tape: You can secure the bottom of the device to
Labeling Requirements
The LIDAR-Lite
you are integrating the device with another product, you must
ensure the FCC ID is visible from the outside of your product.
You are responsible for meeting any other labeling requirements
imposed by the FCC rules and any rules related to the
compliance of your end product.
: You can secure the device to your application using a
3.6 mm (0.14 in.) wide cable tie. You should route the cable
tie through the channel in the center of the device.
your application using double-sided tape. For best results,
you should select a tape that has a high-strength bond.
v4 LED device is an FCC-certified transmitter. If
Connections
LIDAR-Lite v4 LED Connection Diagram
The through-holes on the LIDAR-Lite v4 LED device are
arranged in 2 rows of 5 holes each, with a 2 mm pitch between
each connection.
NOTICE
The LIDAR-Lite v4 LED maximum signal level is 3.3 V. A signal
greater than 3.3 V will damage the device.
Device Dimensions
Pin Pin Name Function V Max
VIN 5 V Power 5 V
GND Ground --
I2C SDA I2C Data 3.3 V
I2C SCL I2C Clock 3.3 V
August 2019
190-02533-00_01
Pin Pin Name Function V Max
DRAFT
GPIOA General Purpose I/O 3.3 V
GPIOB General Purpose I/O 3.3 V
VRETURN nRF52840 DBG 3.3 V
nRESET nRF52840 DBG 3.3 V
SWCLK nRF52840 DBG 3.3 V
SWDIO nRF52840 DBG 3.3 V
Operational Information
Technology
This device measures distance by calculating the time delay
between the transmission of a near-infrared light and its
reception after reflecting off of a target, using the known speed
of light.
The
LIDAR-Lite
Semiconductor. This SoC pairs an ARM Cortex-M4 processor
with 1 MB of flash memory and 256 KB of RAM. The included
2.4GHz multiprotocol radio and S340 SoftDevice support Ultra
Low Power (ULP) wireless technologies, including ANT and
Bluetooth® 5 LE.
The
LIDAR-Lite
that allows the developer to communicate with the device using
several methods. An I2C interface allows the device to be
connected to an external micro-controller, or it can be controlled
and operated wirelessly using the ANT wireless protocol in
accordance with the ANT Ranging Profile.
The
LIDAR-Lite
LE secure DFU bootloader, which enables wireless software
updates using a Bluetooth LE capable device.
Theory of Operation
When the device takes a measurement, it first performs a
receiver adjustment routine, correcting for changing ambient
light levels and allowing maximum sensitivity.
The device sends a reference signal directly from the transmitter
to the receiver. It stores the transmit signature, sets the time
delay for “zero” distance, and recalculates this delay periodically
after several measurements.
Next, the device initiates a measurement by performing a series
of acquisitions. Each acquisition is a transmission of the main
light signal while recording the return signal at the receiver. If
there is a signal match, the result is stored in memory as a
correlation record. The next acquisition is summed with the
previous result. When an object at a certain distance reflects the
light signal back to the device, these repeated acquisitions
cause a peak to emerge, out of the noise, at the corresponding
distance location in the correlation record.
The device integrates acquisitions until the signal peak in the
correlation record reaches a maximum value. If the returned
signal is not strong enough for this to occur, the device stops at
a predetermined maximum acquisition count.
Signal strength is calculated from the magnitude of the signal
record peak and a valid signal threshold is calculated from the
noise floor. If the peak is above this threshold, the measurement
is considered valid and the device will calculate the distance. If
the peak is not above the threshold, it will report 1 cm. When
beginning the next measurement, the device clears the signal
record and starts the sequence again.
Interface
Initialization
When you turn on or reset the device, it performs a self-test
sequence and initializes all registers with default values. After
roughly 22 ms, you can take distance measurements using the
v4 LED contains an nRF52840 SoC from Nordic
v4 LED comes preloaded with an application
v4 LED also comes preloaded with a Bluetooth
I2C interface, the mode control pin, or a wireless ANT
connection.
I2C Interface
This device has a 2-wire, I2C-compatible serial interface. It can
be connected to an I2C bus as a slave device, under the control
of an I2C master device. It supports 400 kHz Fast Mode data
transfer.
The I2C bus operates internally at 3.3 Vdc. Internal 13 kiloohm
pull-up resistors ensure this functionality and allow for a simple
connection to the I2C host.
The device has a 7-bit slave address with a default value of
0x62. The effective 8-bit I2C address is 0xC4 write and 0xC5
read. The device does not respond to a general call. Support is
not provided for 10-bit addressing. The device auto-increments
the register address with successive reads or writes within an
I2C block transfer. This is commonly used to read the two bytes
of a 16-bit value within one transfer. See Obtaining
Measurements from the I2C Interface
For a list of all available control registers, see Control Register
List
, page 5
For more information about the I2C protocol, see I2C Protocol
Information
Obtaining Measurements from the I2C Interface
You can obtain measurement results from the I2C interface.
Write 0x04 to register 0x00.
1
Read register 0x01.
2
Repeat step 2 until bit 0 (LSB) goes low.
3
Read two bytes from 0x10 (low byte 0x10 then high byte
4
0x11) to obtain the 16-bit measured distance in centimeters.
Settings
You can configure the device with alternate parameters for the
distance measurement algorithm. You can use this algorithm to
customize performance by enabling configurations that allow
speed, range, and sensitivity options. See the full control
register list
settings.
Configurable I2C Address
You can change the I2C address from its default to any 7-bit
value. Before you can configure the secondary I2C address, you
must first enable flash storage (0xEA). After you configure the
secondary I2C address, the address persists if you turn off the
device. You can use this process to run multiple devices on a
single bus by enabling a device, changing its address, and then
enabling the next device. Before you can change the I2C
address, the I2C communications bus must read the UNIT_ID
and write it back to the device in a single five-data-byte
transaction with the new I2C address as the fifth byte. Software
template functions for configuring the I2C address are available
at https://github.com/garmin/.
Mode Control Pins
The mode control pins can be used to trigger distance
measurements and check the status of the
These connections are not required. These pins can provide a
simpler and faster method of controlling the device, and they are
intended to be used in conjunction with the I2C interface. For
more information, go to
.
, page 4
(Control Register List, page 5)
.
https://github.com/garmin/
, page 2
.
for additional
LIDAR-Lite
.
v4 LED.
2
Pin Description Functionality Details
DRAFT
GPIO A TRIGGER LIDAR-Lite v4
GPIO B MONITOR LIDAR-Lite v4
Triggering and Reading Distance Measurements
Toggle the TRIGGER pin.
1
Wait for the MONITOR pin to go low.
2
Read two bytes from 0x10 (low byte 0x10, then high byte
3
0x11) to obtain the 16-bit measured distance in centimeters.
NOTE: If you need to take distance measurements as quickly
as possible, you can reverse steps 2 and 3 so the LIDAR-Lite
v4 LED device takes a distance measurement while
performing the I2C register read. When this occurs, the
LIDAR-Lite v4 LED device is in the process of measuring the
distance while the registers are read. The distance returned
is the previously triggered measurement.
ANT
ANT is a practical wireless network protocol running in the 2.4
GHz ISM band. Designed for ultra-low power, ease of use,
efficiency, and scalability, ANT easily handles peer-to-peer, star,
tree, and mesh topologies. Other ANT capable devices can
connect to the LIDAR-Lite v4 LED to control it, receive data from
it, and configure it wirelessly. ANT messages are sent and
received from the
ranging profile.
For more details about the ANT ranging profile and the
capabilities and workings of the ANT wireless protocol, see ANT
Ranging Profile and ANT Message Protocol and Usage at
https://github.com/garmin/.
Connecting Wirelessly Using ANT
Before you can connect to the
you must complete these tasks.
LED
measurement
trigger input
LED BUSY
status output
LIDAR-Lite
v4 LED in accordance to the
Toggle to start a distance
measurement. The
Lite v4 LED starts a distance
measurement on either the
rising or falling edge. If a
distance measurement is
triggered while the device is
busy, the requested
measurement is ignored.
Indicates when the LIDARLite v4 LED is busy. If low,
the device is idle and is ready
to start a distance
measurement. If high, the
device is busy taking a
distance measurement. Wait
for the signal to drop before
you toggle GPIO A to trigger
a distance measurement.
LIDAR-Lite
v4 LED using ANT,
LIDAR-
ANT
• Install Windows 7 Service Pack 1 or higher on your PC
• Install .Net Framework 4.5 or higher on your PC
• Install Visual C++ 2008 SP1 Redistributable Package or
higher on your PC
• Purchase a Garmin®
Connect the USB
1
Download and install the Garmin ANT demo PC application
2
on your computer (https://github.com
Configure and connect the PC application to the LIDAR-Lite
3
v4 LED device as specified in the readme file that is included
with the Garmin
Activating the Bluetooth LE Bootloader
NOTE: If you are installing a custom unsigned application to the
LIDAR-Lite v4 LED, you should first test and debug the custom
application using a J-Link debugging probe before you perform
wireless updates.
The
LIDAR-Lite
Bluetooth LE bootloader that allows you to update the device
software wirelessly. You can use the Nordic Secure DFU
bootloader to install an official update signed by Garmin, or a
developer can use that bootloader to install a custom, unsigned
application.
Disconnect power from the
1
Ground the boot pin (GPIO B).
2
Connect power to the LIDAR-Lite v4 LED device.
3
The
Bluetooth
Mode."
Updating the Firmware Using the Bluetooth LE Bootloader
You can use the
v4 LED firmware using a smartphone equipped with Bluetooth
LE or a PC equipped with an nRF52 DK or nRF52840 dongle.
The firmware is contained in a file called DFU.zip.
Copy the DFU.zip file to a smartphone or PC.
1
NOTE: You can use the DFU.zip file provided by Garmin or a
custom DFU.zip file.
Using the nRF Connect or nRF Toolbox app, start the
2
firmware upgrade using the DFU.zip file you copied.
After the DFU process reaches 100%, verify the new
3
application runs correctly.
For more information about how to update the nRF52840 using
the Nordic secure DFU bootloader, go to https://github.com
/garmin/.
ANT
v4 LED device comes preloaded with a
LE bootloader starts advertising as "LLV4 DFU
Bluetooth
USB-m stick
ANT
stick to your computer.
ANT
/garmin/
demo PC application.
LIDAR-Lite
bootloader to update the LIDAR-Lite
) .
v4 LED device.
3
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