Help troubleshooting Zumo 32U4 left proximity sensor

I recently built a Zumo 32U4 and in running the demo sketches everything seems to be working well with the exception of the left proximity sensor. When I run the “LineAndProximitySensors” example, I see readings for the front and right proximity sensors but not the left (reflected both in the LCD output and serial output). I have double-checked that I jumpered 20 to LFT and that the sketch is initializing all three proximity sensors.

Do you have any suggestions for troubleshooting this? Is there a way to tell if the proximity sensor is bad, or if I soldered something badly, or if there is something else that could be the problem?

Thanks in advance!

I figured it out: culprit was bad soldering. I inspected the solder on the pin 20 on the front sensor array connector and saw that it was sub-optimal. After fixing that up it works.


I am glad you found the problem and were able to fix it; thank you for letting us know.

- Amanda