Adding Servo (extra electrical components) to BTT Octopus

[pfyh2jhr97-cell]

Hi!

I'm fairly new to grblHAL and was having issues in determining the best way to connect additional electrical components such as a servo. There are quite a lot of extra pins on the BTT Octopus, which I also saw through accessing the board map. Unfortunately, I am unsure of how to use / configure them through the web builder? Does anybody have advice on that? Additionally, I thought about connecting an external microcontroller, such as an ESP32, through either UART or IO pins (I would then use an IO Expander). Unfortunately, I was unable to really determine how to make this work and struggled to find similar projects/ questions.

I am really grateful for any help I can get. Thank you so much!

[terjeio]

Use the $pins command to find the pins available for use with M62 - M67. They are flagged as aux with Px or Ex port numbers that can be used with the M-commands.
External I/O expansion can be added in the Web Builder via some I2C chips and/or the FluidNC Airedale serial port expander.
Currently no native pins can be assigned for servos, map changes are required. The FluidNC Airedale can be used for servos but this option is not available yet in the Web Builder.
Modbus and CAN bus based expansion is also possible.