Pins 0 and 1 in Pro Micro cannot be used for output shift register connection

[JaimeLeon2]

Describe the bug A DM13A led driver chip did not work when the chip Latch CLK and DIN where connected to Arduino Pro Micro pins 2, 1, and 0 respectively. It worked flawlessly if connected to pins 4, 3, and 2.

Steps To Reproduce Steps to reproduce the behavior:

1. Wire a DM13A chip as per diagram (no resistor on pin 3 required.
2. Connect 16 leds to pins 5 to 20
3. Create device config in MFConnector specifying pins 2, 1, and 0 for Latch CLK and DIN
4. Create output configs for those 16 leds
5. Run Test mode
6. See that leds do not turn on in sequence.
7. Change wiring to pins 4, 3, and 2
8. Change device config
9. Run test mode again
10. See leds turn on in sequence normally.

Expected behavior Shift register support should work with pin 0 and 1, as these pins are available for general use in a Pro Micro (different from other boards like Mega, Uno and Nano).

Actual behavior Shift register does not work.

Details

• MobiFlight Version: 10.1.4
• FlightSim: Irrelevant
• AddOn: Irrelevant

Additional context None