The Maple runs at a maximum of 72 MHz, has 39 digital input/output pins, 16 analog inputs, native full speed USB, 3 USARTs (hardware serial ports), integrated SPI/I2C support, a power jack, and a reset button.
Features:
- Microcontroller: STM32 F103RB
- Clock Speed: 72 MHz
- Operating Voltage: 3.3V
- Input Voltage (recommended): 3.0V-18V
- Digital I/O Pins: 39
- Analog Input Pins: 16
- Flash Memory: 128 KB
- SRAM: 20KB
- 64 Channel nested vector interrupt handler (including external interrupt on GPIO’s)
- Integrated SPI/I2C and 7 Channels of Direct Memory Access (DMA)
- Supplies up to 800mA @ 3.3v
- Support for low power and sleep modes (<500uA)
- Dimensions: 2.05″x2.1″
I wonder how much of the arduino API it supports/how far it extends it to the stm32 peripherals