Why is my System IC LED lighting up?

I’ve got a simple little board/socket assembled for my Dash. When the Dash is out of the socket, my sketch runs normally. When the Dash is in the socket, my sketch runs normally AND the System IC LED (the one in the opposite corner from the battery connector) is constantly lit. Obviously something on the board (just a few jumpers, pulldown resistors, and messy soldering) is doing something to light the LED, but I can’t figure out where it might be a soldering/wiring error.

What pins would be involved to light the System IC LED?

The pins I’m using are:
D8 - input for monitoring system power input, jumpered to USB_5V, with pulldown resistor to GND.
D16 - input for monitoring external switched loop, with pulldown resistor to GND.
D18 - output to provide power to switched loop

Hi - we’re looking into this. Is it possible that R10 might be grounded?

Yes, R10/D08 has a 10k resistor to ground and a jumper to USB5V in order to monitor USB power state. Is it not a valid GPIO pin? I’ve been basing my design on this pinout diagram: https://content.konekt.io/docs/hardware/konekt-dash/manual/#konekt-dash, is it outdated?

I could absolutely be making some simplistic error as well. I’m no professional; I’m a farmer who enjoys screwing around with electronics.


Unfortunately R10/D08 is not available for general usage. There is a small asterisk on that line in the diagram, but it is misleading. Grounding that pin will cause the System IC LED to illuminate, but will also cause issues with program loading. We’ll be posting a better pinout diagram soon. You should be able to use any other digital pin for your 5V sense.

Gotcha, that’s an easy fix. I saw the asterisk, but had figured that it didn’t apply to the GPIO use…