VOXL as usb2 host not working via j8
Connecting my laptop to voxl via adb works on j8 connecter.
However, an STM based device is not recognized when connecting a client device to voxl using micro-usb to micro-usb cable.
The same device is recognized when connecting via the usb expander (https://docs.modalai.com/usb-expander-and-debug-datasheet/)
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub Bus 001 Device 002: ID 0483:5740 STMicroelectronics STM32F407 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
https://docs.modalai.com/voxl-as-usb-host/ does not specify any special requirements.
Am I missing something? is the micro-usb cable needs to be an OTG cable with ID pin?
Hi @Nirge ,
A standard cable won't work.
Some info here:
From here: https://docs.modalai.com/voxl-as-usb-host/#background
Because the USB3.0 SS pins on the VOXL (Snapdragon 821) cannot support TX/RX swapping, they were set to peripheral mode since the 821 is used mainly in phones and peripheral mode is way more commonly used in a phone configuration. In order for systems to use the standard micro-b to type A female OTG cables, they need to do TX/RX swapping. Since VOXL can't do this, it needs to use a non-standard pinout as its default configuration is peripheral mode in order to get the SS.
@modaltb Using USB 2.
Got my hands on an OTG adapter, seems to be doing the trick.