nanoDLP

andycart

Member

Registered: 2017-12-04

Posts: 1

GPIO Pins State At Boot (RPi 3)

Hi All

I have just completed a DLP build using an RPi 3 with a 800 x 480 5 inch display. The stepper is controlled directly by the Rpi3 via a A4988 board. The issue I have is that the Enable pin is connected to a GPIO but during the boot of the RPi 3 the GPIO seems to be low so the stepper jitters and moves for a few seconds. Once the Rpi has booted everything is fine. The jitter is so bad that the Z axis effector can crash into the top mounted end stop.

So my question is, which of the available GPIO pins (in nanoDLP) can I use for enable that are held low during the boot process?

Regards

Andy