We’ve covered a fair amount of compact Arduino Zero compatible boards based on SAMD21 Cortex-M0+ microcontroller over the years including Exen Proto, Wemos D1 SAMD21, or Seeeduino XIAO with the latter being the smallest of them all at just 23.5 x 17.5 mm.
All those boards come with a USB port (Micro USB or USB-C) by default that makes it easy to work with, but may not be ideal to integrate into projects or final products. That may be why Hamish Morley designed the Minima Arduino Zero compatible module with a size even smaller than the XIAO board at 19.8 x 16.6 mm, and the USB interface exposed through 4 pads instead of a connector.
Minima specifications:
- Microchip SAMD21G18A 32-bit Arm Cortex-M0+ microcontroller @ 48 MHz with 256KB of flash storage, and 32KB of SRAM
- Expansion – 24x castellated pads (2.54mm pitch) with 18 GPIO pins, including 5x analogue capable, plys PWM, SPI, I2C, UART
- Misc – Reset button, Tx/Rx LEDs, red user LED
- Power Supply
- 5V to 16V via VIN pin
- Voltage regulator – 3.3V, 150 mA
- ESD Protection for native USB, reverse voltage protection
- Dimensions – 19.8 x 16.6 mm, SMD ready for hand soldering or reflow
The EAGLE footprint library and Arduino board files can be found on Github. The form factor makes it ideal for integration into wearables or tiny IoT projects, while the 2.54mm pitch headers still make it suitable for prototyping, especially all necessary components (e.g. LDO, ESD circuit protection) are already integrated into the board. Alternatively, there’s also an optional breakout board with a MicroUSB port and through holes.
It’s not the first time we write about a SAMD21 module, as the microZERO module offers another option with more I/Os (32), a CAN transceiver, and 16MB SPI flash at the cost of being larger (32x20mm).
The Minina board has launched on Kickstarter with the 1,000 GBP funding goal, or about $1,400 US, already surpassed. Perks start at $23 for the board only, but there are other options including a $95 IoT Kit with a baseboard equipped with SIM808 cellular and GPS module, a battery charger, and an SPI flash. Shipping is free to 3GBP to the UK, and $13.9 to $16.8 US to the rest of the world. Rewards are expected to ship in July or August.
Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.
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I don’t understand why they didn’t move the USB+/- between the power pins to respect the pinout of a USB-A connector, easing the use of the board in certain projects by simply allowing to directy solder a male connector on it.
Does seem weird. I wonder if it was a routing thing.
If I have a “connector” like that I don’t put it in the schematic until I’ve routed most of the board and can see the least frustrating to route pinout.
$23? What am I missing?
Projects from Europe in small quantities tend to be more expensive.