Thanks for the great docs! I ran into some issues during my build with figuring out how to power the servos. As a new builder it might be helpful to add some information to the docs about powering the servos and how that servo power then gets used on the PA9685 board. I can update the docs if you're open to PRs : ). The problem I ran into was that the hardware build guide didn't mention that the PCA9685 servo rail
(V+) requires its own 5–6V power source.
Following the guide exactly, the PCA9685 receives logic power from the Pi
(I²C works), but the servos remain completely unpowered unless:
- the ESC provides a 5–6V BEC on its 3-wire connector, or
- a separate 5–6V battery/BEC is connected to the V+ screw terminals.
If neither is present, users will see:
- servos not moving during
donkey calibrate
- no twitch/buzz on startup
- I²C detection at 0x40 working but no PWM output response
This small clarification would prevent a common silent-failure scenario for new builders like me : ).
Thanks for the great docs! I ran into some issues during my build with figuring out how to power the servos. As a new builder it might be helpful to add some information to the docs about powering the servos and how that servo power then gets used on the PA9685 board. I can update the docs if you're open to PRs : ). The problem I ran into was that the hardware build guide didn't mention that the PCA9685 servo rail
(V+) requires its own 5–6V power source.
Following the guide exactly, the PCA9685 receives logic power from the Pi
(I²C works), but the servos remain completely unpowered unless:
If neither is present, users will see:
donkey calibrateThis small clarification would prevent a common silent-failure scenario for new builders like me : ).