Wiring a external button reset, possible?

[marcossfernandez]

Hi everyone,

We use the Robin Nano V3 board standalone (no LCD/TFT screen), connected by USB to a Raspberry PI 4, where a host controls it. All it's working really fine. All this electronics are into a enclosure with proper forced ventilation, but we need to install a reset switch for the MKS board, so the user haven't direct access to the boards.

There is a EXP2 header with RESET (8) and GND(8) pins. But i can see that the reset it is connected also to SPI1_CS(4) pin.

Also, the reset PIN is direct connected to the SOC NRST pin, so I doubt if its safe to short EXP2 reset and GND pin. I'm prety sure that's very bad.

The onboard reset button installed goes thru a capacitor and resistor prior to reach the SOC. Previous boards we had been used (BTT SKR2) burn the SOC when EXT2 reset its short to ground, almost any time we tested. We don't want to do the same stupid thing.

So what is the secure way of install a external reset switch into the MKS Nano V3 or MKS Eagle V1.0??

The printer must have an mandatory external reset.

Please give me advice as soon you can, so we are in a hurry to finish this printer and give to the client. Thank you.