Hello all, I’ve recently traded in my lidarlite v3 for a lightware because i was having issues with it on my pixhawk cube and now I cant seem to make the cube see the lightware sf 11 sensor despite wiring it and configuring it as the wiki stated for that model. The TX and RX lines are crossed and the power is straight through. When I plug the sensor into the pc and use the console program it reads out distances and shows it operating properly. After configuring the parameters and rebooting the pixhawk the hud displays bad lidar health and status shows nothing under sonar. Is there an extra config step I missed or maybe the TX and RX lines are not supposed to be crossed? I have it on the Telem 2 port if that matters. Really confused here, any input is appreciated.
Hm, some things you can do to debug:
- Plug into the computer and verify that the baudrate setting is the same as what you set SERIAL2_BAUD parameter to.
- Make sure only SERIAL2_PROTOCOL = 9. I’ve had an issue where configuring multiple serial ports for rangefinder caused the device to not be recognized.
- Try swapping the TX and RX wires. It’s easy to get them mixed up, ugh.
- Plug the lidar into the Pixhawk and use a digital camera (e.g, your phone) to look straight into the lidar to see if the laser is on. This will verify that the lidar is at least powered on and operating. Some cameras have an IR filter, so this method isn’t 100%.
Good call on checking with a camera. when plugged into the pc using the micro usb i can see a faint purpleish dot. When powered off the serial I’m seeing nothing. Is it possible it doesnt have enough power? I have a Maunch electronics BEC at 5.35 volts powering the pixhawk, rx reciever and low power telemetry radio. I do have an onboard backup bec i could wire it into although im not sure how to go about that. I noticed the light on the side of the lidar blinks red then goes off when its booted on the drone but when it’s booted using the micro usb it stays on solid red.
To check if it’s power related, do a test setup using telem1. It’s got a separate supply from the other uarts.
Ok I gave that a shot on Telem 1 and still the same outcome. No visible laser either. It’s worth noting I’ve also tried swapping the tx and rx at this point too.
Ok it seems I’ve gotten it working. It was a low power issue. Thanks to you two for helping me troubleshoot it. Apparently the main bec didn’t give the range finder enough power so I wired it in using a common ground and a second onboard backup bec and it works like a charm. Same way the wiki tells you to wire the lidarlite on i2c except with serial is basically what I did.
For future reference to anyone else it seems like if the light on the lightware strobes then shuts off after giving it power instead of staying steady red that may be an indicator of low voltage.