Dim green LED

The green LED on the bottom of my 3pi is very dim. I checked the voltage and it is reading 1.7 volts across the green LED (as well as the red LED – that one is nice and bright). I thought perhaps it might be a defect with the LED itself; so, i soldered one of the optional LEDs to the pins which, I believe, simply run parallel to the surface mount green LED. The optional LED is also very dim. My batteries are fully charged. Any ideas what the problem might be, and can I fix it myself?


How are you turning it on? Can you post the simplest code that isn’t doing what you want it to? The LED you soldered in was probably in the component spot designated D4b on the simplified schematic.

- Ryan

It’s running the most recent version of the slave program (I’m not sure where exactly the LED’s are being turned on in the code) – I’ve recently added the m3pi/mbed expansion. Also, you are correct, the LED I added is in D4b; however, it is both LED’s, D4a and D4b that are dim. Also, just so there isn’t any confusion, this LED has always been dim, it’s not just since I added the expansion.

The default serial slave program does not have a command for turning on the LEDs on the 3pi. The LEDs are probably partially lit up up because the LCD uses the same pin as the LED. If you wanted to turn it on, you’d have modify the serial slave code.

- Ryan

Thanks, I will check this out.

When I explicitly turn on the green LED in code, it works. Thanks again!