Apollo2’s hidden USB

Apollo2’s hidden USB is not a hidden hardware feature, but software bit-banging using Apollo2s flexible GPIOs including the capability to drive 1.5k pullup resistors on special pins used with I2C.The following picture shows the connection between MCU and USB port:

The solution supports low-speed USB for realizing HID USB transfers for example. One idea is to add an USB HID based bootloader.

The demo available on github https://github.com/schreinerman/apollo2_hiddenusb emulates an USB keyboard and is opening the start menu and typing “April Joke” and return (opens Internet Explorer searching for April Joke).



These are the instructions how to try the demo:

Download apollo2_hiddenusb.bin to Apollo2 MCU

Do the USB Cable connection:

  • Connect D- to AMAPHEVB GPIO8
  • Connect D+ to AMAPHEVB GPIO9
  • Connect GND to AMAPHEVB GND
  • Connect VBUS (5V) to AMAPHEVB 5V (!!not to VCC!!)

Last Step:

  • Connect USB to PC.

Wait 15 seconds and see the result on a Windows PC

See also http://shop.feeu.com/Shops/es966226/Products/AMAPHEVB to order a board

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