Hi! I’m from team 3103, Iron Plaid. We’re competing at Lone Star North right now, and we’ve come across a serious(ly frustrating) issue with our LiDAR sensor.
First, it’s about 10 cm off from reality, but we can deal with that. Our issue comes when it stops updating the value it’s returning about 30 seconds to a minute after the robot is first enabled and then won’t start working until power is cycled or the RIO is restarted.
We’ve had it working on our practice robot for weeks, so we’re pretty sure it’s not a code issue. Power, ground, SCL, and SDA are all wired correctly. There could be a problem with the soldering on the capacitor, but we’re not sure that would cause the issues we’re seeing and don’t want to tear it all apart if we don’t have to.
Any thoughts? Has anyone had similar problems?
What is the model # of the LIDAR?
How are you powering it?
What else is on the circuit powering the LIDAR?
It’s a LiDAR lite v3
We’re powering it through the VRM in a 5V/500mA plug, and we’re communicating with it via I2C on the RIO, and it’s the only device communicating via I2C. Our router is the only other thing on the VRM, and that’s been getting power consistently.
You should have more than enough power on the 5v500ma rail. Just for kicks, you might want to move it to the 5v2A rail since nothing else is there. Just in case the VRM is failing.
It could be bad or noisy wires, and it is loosing communications. Is there a function to reset the I2C interface? You might want to try that if you get no response after 1 second.
Tough to do while you are at a competition, but you could check to see if PWM is working, or the LIDAR is failing. We had a NavX board go bad during competition last year. Fortunately we had an extra one and swapped it out.
Thanks for the advice! I think we’re going to swap the competition LiDAR out for the one on our practice bot tomorrow, and I’ll update with any findings.