Update index.md

Author: maebemae

6660/index.md

@@ -7,3 +7,7 @@ site: https://github.com/maebemae/TheButton
 source: https://github.com/maebemae/TheButton
 ---
 A velocity sensitive macro button. Based on the velocity of the button press, a relevant message is typed out.
+
+The project is based on a STM32C071 MCU, with an off the shelf Emergency Mushroom button, and keyswitch.
+
+The firmware uses a mix of STM32CubeMX + STM32 HAL and https://github.com/gbm-ii/gbmUSBdevice as the main usb driver