ESP32 Forum

> Time to get the setup smaller when Arduino Pro mini USB host shield will arrive, with Arduino Pro mini.
>
Still waiting for the first of the boards ordered at different aliexpress shops to arrive in Germany (hand over to airline 12/19 and 12/20, not sure whether airline use container ships since both have not reached Gearmany yet),

I found one other posting talking on different USB host boards for use with ESP32 (14£ or 15£ instead of <4$):
https://www.esp32.com/viewtopic.php?f=2 ... eld#p19400

I have been experimenting with using a SAMD21 (Trinket M0) in USB host mode to do something similar. The keyboard data (ASCII or USB HID report) is exported via UART so the ESP32 or ESP8266 does not need to know anything about USB host mode. Also this means it works with MicroPython, Espruino, Arduino, IDK, etc. I think it similar to using Due native USB but using a Trinket M0 instead. Trinket M0 can be programmed by dropping firmware UF2 files on to its USB drive so it is not necessary to build the firmware from source code.

Firmware for a USB Host MIDI bi-directional converter is also available. It could be used with AppleMIDI/RTP-MIDI over WiFi to make USB MIDI devices wireless.

The disadvantage of the MAX3421 USB host shield is there is no software support for it in MicroPython or Espruino. It does work in Arduino though.

https://github.com/gdsports/usbhostcopro