ARM Cortex-M in Arduino form factor, and consumes very little power.
This is one of my "design challenges" to myself:
- Arduino-compatible form factor,
- Take an 48-pin STM32 microcontroller (since STM32F103CBT6 are that cheap,)
- Bring all I/O pins out somewhere, be it the connectors, JTAG or USB,
- No two pins can be shorted together,
- Use only switch-mode power supply,
- Two layer PCB only,
- Single side load.
- STM32 microcontroller in LQFP-48 package. I have tested the following:
- STM32F072C8T6 (Cortex-M0 @48MHz)
- STM32F103CBT6 (Cortex-M3 @72MHz)
- STM32L151CCT6 (Cortex-M3 @32MHz, ULP)
- STM32F303CCT6 (Cortex-M4F @72MHz)
- STM32F373CCT6 (Cortex-M4F @72MHz)
- WCH CH340B: USB to UART adapter.
- TI TPS562200: VIN to 5V buck converter.
- TI LM3671-3.3: 5V to 3.3V buck converter.
This is open source hardware, licensed under the 3-clause BSD license.