Table of Contents
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|
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:
Then, there is a test routine:
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:
Plug the SF02/F into TELEM2 or Serial 4/5 of Pixhawk. The wiring of the SF02/F is explained on the Rangefinder page.
This series of ultrasonic rangefinders has an I2C interface. Up to 6 sensors are supported on the I2C bus.