Using VOXL Mini 4-in-1 ESC (UART) + VOXL 2 IO (PWM) at the same time

Gary Holmgren

Hi all, I’d like to run the VOXL Mini 4-in-1 ESC over UART with VOXL 2 and use the VOXL 2 IO expansion board to get a few extra PWM channels in PX4.

From the docs, the ESC uses J18 on VOXL 2. The IO board is also shown on J18 in some examples. Can I keep the ESC on J18 and put the IO board on J19 instead, then run both (voxl_esc on QUP2 and voxl2_io on QUP7) so I can map extra PWM outputs in QGC?

Hardware:

VOXL 2
VOXL Mini 4-in-1 ESC (UART)
VOXL 2 IO expansion board
If this is supported, are there any specific PX4 params or startup script changes I should make?

Links for reference:
https://docs.modalai.com/voxl2-io-user-guide/
https://docs.modalai.com/voxl-mini-esc-datasheet/

Thanks!

Alex Kushleyev

@Gary-Holmgren,

Yes the two can work together.

You will need to modify the /usr/bin/voxl-px4-start file which loads all the modules based on the contents of /etc/modalai/voxl-px4.conf.

The voxl esc + voxl 2 io board is not a standard configuration, but you just need to make sure the following modules are started:

qshell voxl_esc start #(will start on default QUP2 / slpi uart port 2)
qshell voxl2_io start -p 7 #(use QUP7)

You can also just manually start these modules in px4 shell for testing. Watch the output of both modules in px4 console, because both modules will detect the corresponding board and will print useful information whether the corresponding board has been detected on the specified port). For this purpose, it may be easier to run voxl-px4 in foreground (instead of a service):

voxl-px4 -d

(-d disables the daemon mode and will let you interact with the px4 shell)

Alex

Gary Holmgren

@Alex-Kushleyev Thanks for clarifying this!