The MapleTree Mini RET6 board consists of the essentials: a fast processor with lots of peripherals. At the center of MapleTree Mini RET6 is a 72MHz ARM Cortex M3 chip, 512KB Flash and 64KB RAM, providing the increased computational power desired by more advanced users. In the past, ARM processors were notoriously unfriendly in non-professional environments due to proprietary tool chains and unfamiliar instruction sets. Because of this, they were conspicuously absent from classrooms and hobbyists's workbenches. Our aims to change this by providing an ARM tool-chain built from open source components and a programming environment that is intuitively easy to use. For those of us who love and are familiar with Arduino, MapleTree Mini RET6 is offered in an Arduino-compatible format, complete with Arduino pin layouts and programming environment. In the future, a Cortex native version is available in order to take full advantage of this fantastic micro-controller.

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The MapleTree Mini RET6 is a microcontroller board based on the STM32F103RE microprocessor. The MapleTree Mini RET6 runs at a maximum of 72 MHz, has 39 digital input/output pins, 16 analog inputs, 1 DAC, native full speed USB, 3 USARTs (hardware serial ports), integrated SPI/I2C support, and a reset button. MapleTree Mini RET6 is programmable over USB via our provided DFU bootloader, no extra hardware required! Users can also program the onboard program flash via external JTAG interface. MapleTree Mini RET6 offers security support for read/write protected addresses, as well as User and Handler processor modes. It has a real-time sysTick, useful for a real time OS or any timing sensitive applications. 6 advanced interrupt timers will help you here as well. MapleTree RET6 can be powered via USB, a wall adapter, or it can run off of a rechargeable LiPo battery (see below for more info). The MapleTree Mini RET6 is compatible with shields designed for the Arduino Duemilanove or Diecimila.


  • Microcontroller: STM32F103RET6
  • Clock speed: 72 MHz
  • Operating voltage: 3.3V
  • Powered Via Micro USB or Li-ion Battery with Power Path
  • Digital I/O pins: 39
  • Analog Input pins: 16
  • DAC: 2
  • Flash memory: 512KB
  • SRAM: 64KB
  • 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 600mA @ 3.3v( AP2112K-3.3TRG1 )
  • Support for low power and sleep modes (<600uA)
  • Dimensions: 2.5x5.5CM

MapleTree Mini RET6 is a great way to get started with an advanced 32 bit-processor that, until now, has principally lived in the commercial domain. Take your projects to the next level with MapleTree Mini RET6's fast clock, sophisticated interrupt architecture, and loads of built-in peripherals.


MapleTree Mini RET6 can be programmed using an Arduino-style, sketch-based programming environment, which is open-source and can be downloaded online at our website. The Cortex-M3 on MapleTree Mini RET6 comes pre-programmed with a boot-loader – allowing users to upload new code onto it using the USB interface (supported directly by the Cortex-M3), without the need for an external hardware programmer. You can also program the microcontroller directly with an external JTAG interface.


MapleTree Mini RET6 is refer to Maple of Leaf Labs, an open source STM32 hardware. We thanks Leaf Labs very much.