I have an issue where digital pins are pulled to HIGH when powering up the Photon. This causes a servo to jump from 0 degrees to almost 50 degrees until Setup attaches servo and sets it to 0 degrees. If powering up again(example on-off, then again on-off) it will jump from 0 to 50 degrees then 50 …

@eLumaLite , to add to what @ninjatill pointed out, unless you change GPIO pins, the only other way to get around this issue is to add tri-state buffers between the pins and your servos which will only be enabled via a separate GPIO (non JTAG) once your code is running. The ENable pin on the buffers…

Thank you. I will give it a shot on other pins to see if I can correct the issue. I am using D0 for the servo and D3 and D7 for 2 relays.

Digital pins pulled HIGH when powered up

Troubleshooting

ninjatill July 23, 2018, 6:01pm 2

I believe your question may be answered in the following thread. As @Ric and @rickkas7 explained, if you are using pins D3-D7, they are used by JTAG and are briefly pulled high (D6 low and D4 floats) at startup.

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Digital pins pulled HIGH when powered up

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