Force GPIO pin HIGH when bootloader running

ArduCopter Copter 4.3
1

I want to force GPIOs high when bootloader is running.

I tried to config add new define in hwdef-bl.dat but not success.

ensure PWM output low

PH10 M1 OUTPUT OPENDRAIN HIGH
PH11 M2 OUTPUT OPENDRAIN HIGH
PH12 M3 OUTPUT OPENDRAIN HIGH
PI0 M4 OUTPUT OPENDRAIN HIGH

But GPIO not high when bootloder is running.

Board : CUAV-Nora
Firmware : ArduCopter 4.0

Please Advise.

Thank you

2

Are you trying to solve a problem where some external device is affected by the GPIO output status during boot? Before the GPIO output is set to it’s desired at-rest state?

Rather than changing the GPIO operation via firmware, can you apply a delay to the power supply of the external device?
For example using a MOSFET with delay.

2 Likes
3

Yes. Because of floating GPIO, ESC state is missed.

First I try to solve the problem without change any hardware.

4

Try this maybe?

DEFAULTGPIO OUTPUT HIGH PULLUP