SPX-21316 visible spectrum emitter: order of connections and power-up?

SPARK-X
1

I’ve just successfully tested this great board, but I’d like to confirm the correct order according to which power should be applied to the boards, knowing that I use the SPX-21316 with a micromod ATP board (with artemis MCU) powered by my notebook and the SPX-21316 is powered by an external PSU.

This is how I did:

  1. with NO power applied to either the micromod ATP nor the SPX board, connect both boards with a qwicc cable

  2. connect the ATP board to the notebook’s USB port and upload the code to the artemis

  3. then apply power to the SPX board

Disconnection: un-power the SPX board, followed by the ATP.

I didn’t get any smoke and the LEDs operated fine, but is this the correct way to proceed?

What do you recommend when an MCU connects to a board via QWICC and both are powered separately?

Thanks, Ludo

2

That is perfect for uploading code or use :slight_smile:

You could also likely just power the SPX board after having it programmed and it could power the ATP board over qwiic easily (artemis ATP doesn’t draw much power generally)

But the way you’re doing it now is fine too :slight_smile:

3

Russell is correct, your power up is fine! It shouldn’t matter, in fact, what order you power everything because the power supply to the LED drivers is basically isolated from the controller so nothing will be damaged no matter when power is applied to the LED_VIN input.

That said, powering the LED drivers after the controller is already running is a good way to avoid unexpected behavior from the LEDs being powered with nothing pulling on the driver control lines.

I’m glad you like the board!