gsh wrote: ↑
Fri Sep 21, 2018 2:35 pm
If you're happy with software solution then you can ignore the OTG_ID pin completely and just add dr_mode=peripheral to the dtoverlay line
Otherwise if you want to be able to use the special host cable in the uUSB plug so you can use OTG to switch between host and device then you will need to wire pin 4 on the uUSB connector to the OTG_ID pin on the compute module.
Don't forget to wire a pull up to the HPD (hotplug detect) pin if you're not using HDMI)
Thanks for both options. I would of liked to have used the software solution but as I plan to sell this product, rather make it easier to just wire up the pin then give consumer cable for powering and then keep a USB OTG cable for debugging.
HPD I'm assuming according to the datasheet you're talking about pin 88 - GPIO46_1V8
I know this might sound daft but what resistance would you reccomend for the pull up and I'm assuming the resistor would have to be powered by 1.8v? Or could I simply connect it into the 3.3v/5v I've already got connected into the cm3?