Antenna light comes on intermittently at power-up

In using my power adapter set up (described in the post Hands on ROS Chapter 9), I’ve had several instances of the antenna light turning on- very bright white. When this happens it seems to take longer than usual for the power light to stop blinking green and turn a steady green. Once it does I can SSH and log in to the robot just fine. I found @cyclicalobsessive 's post Antenna WiFi Indicator Stop/Start. However it doesn’t directly address my issue - the antenna LED turn on as soon as I power up the GPG3 board, before the Raspberry Pi has even had time to finish booting. Granted, my adapter is somewhat improvised, but the barrel jack should be pretty much a pass-through. I went through the GoPiGo3 Documentation - there’s no mention of the light. I was just wondering if the antenna LED turning on white is supposed to be some kind of status/problem indicator? It’s not consistent, and has occurred both connected to my battery pack and to a 12V “wall wart”.
/K

1 Like

Nope, the antenna is never used for anything other than connection status.
I don’t think I’ve ever seen this particular behaviour before. I would have to double check the electronics to see what it could be.
Does it have the same behaviour if you use the regular battery pack without the LIDAR?

1 Like

It had never happened before. I just tried again a number of times, and can’t recreate it. But then again I also tried again with the battery pack going through my adapter, and it also hasn’t happened again that way. But even yesterday it didn’t occur every time I powered up. And yesterday it’s after I’d been running things for a while, so maybe the components need to warm up for it to happen??? If it continues to occur I’ll try to determine the more specific circumstances.
Thanks,
/K

1 Like

Try a can of air.

If you turn it upside down, it’s a great way to improvise some cold-spray to test temperature sensitivity. Just be careful and use SHORT bursts.

Also, you may want to take a real close look at the quality and consistency of your power. Both cleoqc and cyclicalobsessive can tell you about the absolute hell I went through back when I first built Charlie, before I knew how critical clean power can be.

I even wrote a posting here on when [something] goes wrong - check the power first!

Thanks for the suggestion. Fortunately it hasn’t happened again, but will try this if it does.
/K

1 Like

OK, weird. It’s happening again, but different.
Just got back from a 2 week socially-distant road trip out west. Fired up my robot using the new USB power supply. This time the GoPiGo3’s LEFT eye LED came on GREEN (not the WiFi LED this time). This happened right away, so no warm components. I was able to run the control_panel_gui.py program via SSH. It showed the voltage as 10.5V. The LED’s did not respond to the control panel buttons, but the blinkers did, and the motors ran fine. I then used the Python REPL to import gopigo3 and try controlling directly from Python. I couldn’t turn on or off any of the LEDs (left eye, right eye, or WiFi). I could control the blinker LEDs however via the REPL. The left LED cam on that way through several reboots. After a subsequent reboot, the RIGHT eye came on WHITE. One more reboot after that - no LEDs came on. However on checking, I still couldn’t turn on/off the LEDs (either through the REPL or the control panel GUI); could still control the blinker LEDs though. I’ve tried a few more reboots - no LEDs come on.

Everything else seems to run OK. Like I said - weird.

/K

1 Like

It’s October, maybe your 'bot is haunted?

You can always try wiring some garlic in parallel with your power supply. :wink:

Seriously, I’d look closely at the power source, garlic or otherwise. It might be dipping at power-on. See if you can get a 2 amp+ supply at 12v across it. Temporarily wire one across the power jack (or a plug adapter) just to absolutely guarantee that the supply isn’t the issue.

Thanks @jimrh. This has happened though with 3 different power supplies (including one plugged into the wall), so the power supply doesn’t seem to be the issue.
/K

1 Like