Externally triggering tethered capture


I’m using a digital camera to scan film negatives, and I’ve created a custom LED array on a PCB with the correct wavelengths of light for accurate color rendition. To control the LED board, I open a UART connection to a microcontroller on the board which controls the LEDs and issue commands over serial to turn the LEDs on/off, change their intensity, etc. I have a program on my computer that scripts these operations, so I can tell the board “turn on the red channel, wait 1 second, then blue, wait 1 second” etc.

It would be ideal if I could control my tethered camera at the same time through darktable. Darktable’s tethering mode is great, but I’m not aware of any method to trigger a capture externally. Ideally I would have a process running on my computer that issues commands to the LED board, and communicates with darktable using some kind of IPC to trigger a capture at the right time.

Is there a facility for this? Thanks.