* Choice of three SAM M0+ chips:
- SAMD21J (this is among the first SAM M0+ MCUs, also used in the Arduino Zero)
- SAML21J (low power features w/ on-chip buck converter, enhanced analog peripherals, crypto)
- SAMC21J (5V support on board, CAN instead of USB, Sigma-Delta and SAR ADCs)
- All chips available with up to 256KB FLASH and 32KB of SRAM
* All components were selected with low power use in mind
* XBEE / XBEE Pro form factor socket with support for high power radios (ie: LTE cellular modem)
* MicroSD card slot
* Motor controller / relay driver (with support for DC and stepper motors) up to 2.4A, 2.7V-16V
* Level shifter (which can also be used for servos)
* Optional serial (SPI) memory device: 128KB SRAM (with battery backup support on board), 64KB EEPROM, or 512KB FLASH
* Optional sensors: 3-axis accelerometer / 3-axis gyroscope with interrupt available, pressure sensor / temperature sensor
* 2A buck converter with input up to 16V with configurable output voltage
* Power multiplexer automatically selects between the buck converter and USB Vbus as a source
* Dual output switch can be used for host mode USB and/or an auxiliary output
* Current and voltage measurement of the external Vin source (with I2C and/or analog output supported)
* Two 3.3V linear regulators (250mA and 1.5A). The 1.5A regulator can be powered down
(MicroSD, XBee, and external devices can be connected to this rail).
* Two crystals, a button and an LED
* 55 solder jumpers for extreme flexibility. The power supply has several configurations
(ie: separate 5V and 3.3V rails or use buck to generate 3.6V and post-regulate this to 3.3V).
ZeptoProg II small low-cost AVRISP mkII compatible programmer and
development tool with simple logic analyzer, USB to serial bridge,
SPI interface, GPIO, PWM, frequency output, and frequency measurement.
Accessible via command line or Java GUI (Windows and Linux).