Table of Contents
Rangefinder
LIDAR-lite
PWM Interface Wiring
Pixhawk AUX servo pin | Lidar-Lite pin | Comment |
---|---|---|
AUX row 5 (bottom) | 3 / PWM | PWM input of the Lidar Lite. Needs a 470 Ohm pull-down (to GND) |
AUX row 6 (center) | 1 / +5V | Power supply |
AUX row 6 (top) | 6 / GND | Ground |
AUX row 6 (bottom) | 2 / RESET | Reset line of the sensor |
PWM usage
To test/debug the Lidar-lite, connect to nsh and try:
pwm_input start pwm_input test ll40ls start pwm ll40ls test pwm ll40ls info pwm
LightWare SF02/F Laser Rangefinder (40 m)
The picture below shows the wiring of the SF02/F for a serial port of Pixhawk. With 150 mA maximum current it can be connected to any of the four serial ports.
The pinout has been validated. Note: Pin 10 / COM of the SF02/F is internally connected to pin 2 and does not need to be connected in this setup.
Pixhawk UART pin | SF02/F pin | Comment |
---|---|---|
1 / +5V | 3 / +5V | Power supply |
2 / TX | 9 / RX | 3.3V UART SF02/F receive |
3 / RX | 8 / TX | 3.3V UART SF02/F transmit |
6 / GND | 2 / - | Ground |
It is neccessary to check, if the SF02 Laser is set to 9600 baud. Otherwise, PX4 Firmware will not recognize the datastream. To set the correct baud-rate, you have to connect the Laser via USB to the lightware terminal. By pressing the space-bar you get to the settings. Changing parameters has to be done with pressing the corresponding char-keys, to change the values.
To test, if the driver works, it can be started with Tera Term VT:
sf0x start
Then, there is a test routine:
sf0x test
It will create outputs (RAW) similar to this for 0 to 40 meters:
SF02/F Range Finder Setup
To start the sensor in PX4, please add a file called etc/extras.txt
to your microSD card with this content:
sf0x start
Plug the SF02/F into TELEM2 or Serial 4/5 of Pixhawk. The wiring of the SF02/F is explained on the Rangefinder page.
MaxBotix I2CXL-MaxSonar-EZ
This series of ultrasonic rangefinders has an I2C interface. Up to 6 sensors are supported on the I2C bus.