STM32F4DISCOVERY is evaluation board with 32 bit ARM microcontroller and I’m surprised what features it can offer for around 11 euros.
- STM32F407VGT6 32-bit ARM microcontroller @168 MHz with 1 MB Flash, 192 KB RAM.
- Hardware debugging(limited On-board ST-LINK) via USB
- USB OTG port for connecting mouses, keyboards, USB flash drives
- 3 axis digital accelerometer ±2g/±8g with programmable triggers
- Digital microphone
- DAC with microphone socket
- 4 user controllable LED’s