FLIR Lepton

Table of contents

1. Overview
2. Supported Carrier Boards
3. Configuration
   1. Config File
4. Pipes
5. Shutter Control
6. Command Line Options
7. Source Code

Overview

voxl-lepton-server (v1.4.x) is a background systemd service that publishes thermal images from a FLIR Lepton 3.5, connected via SPI and I2C, to the Modal Pipe Architecture as a camera. Currently only for QRB5165-based platforms (VOXL 2).

If you are connecting a Lepton via USB, please see voxl-uvc-flir

Supports the following FLIR cameras:

• Lepton V3.5

Images are published at the Lepton’s native 160x120 resolution at 9 fps and can be viewed live with voxl-portal.

Supported Carrier Boards

The Lepton can be connected directly to the VOXL 2 J10 connector (SPI-only) or through one of the following ModalAI carrier boards:

The M0187, M0188, and M0216/M0226 IO expanders are auto-detected at runtime over I2C.

Configuration

Like all MPA services, voxl-lepton-server has a configuration script to enable or disable the service and set up the config file for your hardware:

voxl2:/$ voxl-configure-lepton -h

Usage:
voxl-configure-lepton {MODE}

Valid Modes are:

disable               disable the service
VOXL2_J10             configure for SPI-only connection on VOXL2 J10
m0130                 configure for SPI+I2C connection on M0130 (VOXL2 only)
m0130_flow            M0130 on VOXL2 with flow shutter mode
m0130_manual          M0130 on VOXL2 with manual shutter mode
m0173                 configure for SPI+I2C connection on M0173
m0173_manual          like above but with manual shutter
m0173_rotated         like above but rotated image for Starling 2
m0173_rotated_manual  like above but with manual shutter
m0188                configure for I2C connection on M0188
enable                enable the service, leave config file alone

show this help message:
voxl-configure-lepton help

An m0141 mode is also accepted for configuring the M0141 board.

Config File

The service reads its configuration from /etc/modalai/voxl-lepton-server.conf. The available fields and their defaults are:

Shutter modes:

• Auto shutter mode is the factory default. The Lepton automatically runs the FFC (flat-field correction) shutter every 3 minutes or during large sensor temperature swings.
• Manual shutter mode disables the shutter unless manually commanded via the control pipe or the voxl-lepton-shutter utility.
• Flow shutter mode is specific to using the FLIR for optical flow position hold. It runs the shutter every flow_shutter_s seconds on the ground and while flying in manual or acro mode. In position mode it lets the Lepton decide when to run the shutter, but with the updated in-air parameters above.

Pipes

voxl-lepton-server publishes the following pipes in /run/mpa/:

Shutter Control

The voxl-lepton-shutter utility changes the shutter mode while voxl-lepton-server is running, forces an FFC shutter calibration, or reboots the Lepton. It sends commands over the lepton0_raw control pipe and requires en_i2c to be enabled.

voxl-lepton-shutter auto
voxl-lepton-shutter manual
voxl-lepton-shutter flow
voxl-lepton-shutter run
voxl-lepton-shutter reboot

The run command can be used in either manual or auto mode. Set the default mode with shutter_mode in /etc/modalai/voxl-lepton-server.conf.

Command Line Options

For debugging, voxl-lepton-server can be run manually from the command line:

voxl2:/$ voxl-lepton-server -h
Usage: voxl-lepton-server <options>
Options:
-c, --config      load/create config file only, used by configurator
-d, --debug       Show debug messages.
-e, --debug_ffc   debug messages for shutter and CCI
-h, --help        Show help.
-t, --timing      Enable timing debug print messages
-v, --verbose     Enable verbose messages
-x, --crystal_on  Turn the m0226 crystal on only, then exit
-y, --crystal_off Turn the m0226 crystal off only, then exit

Source Code

Source Code