Verified 2026-10
arduino ATSAMD21G18A MKR WAN 1310
MKR-form-factor LoRa board on an ATSAMD21G18A (48 MHz Cortex-M0+, 256 kB flash, 32 kB RAM) with a Murata CMWX1ZZABZ module (SX1276, +20 dBm), ATECC508 crypto and 16 Mbit SPI flash - 3.3 V only, not 5 V tolerant, VIN 4.5-5.5 V - EUR 49.00.
Place this board on a carrier in the editor →
Logic level3.3 V
Part & documents
| Headline part | ATSAMD21G18A |
|---|---|
| Data sheet | ATSAMD21G18A data sheet → |
| Source | store.arduino.cc/products/arduino-mkr-wan-1310 → |
Specs
| MCU | Microchip ATSAMD21G18A (Arm Cortex-M0+ at up to 48 MHz, 256 kB flash, 32 kB SRAM) with a Murata CMWX1ZZABZ LoRa module (STM32L0 + Semtech SX1276) |
|---|---|
| Clock | 48 MHz |
| RAM | 32 KB |
Pinout
38 pads, as the vendor numbers them.
| # | Name | Function | Signals |
|---|---|---|---|
| 1 | AREF | Header pad 1 (the vendor numbers the header connector 1-28): Analog, the ADC's external reference input | analogue reference |
| 2 | A0/DAC0 | Header pad 2 (the vendor numbers the header connector 1-28): ADC in / DAC out, can be used as GPIO | analogue 0, DAC output, GPIO |
| 3 | A1 | Header pad 3 (the vendor numbers the header connector 1-28): ADC in, can be used as GPIO | analogue 1, GPIO |
| 4 | A2 | Header pad 4 (the vendor numbers the header connector 1-28): ADC in, can be used as GPIO | analogue 2, GPIO |
| 5 | A3 | Header pad 5 (the vendor numbers the header connector 1-28): ADC in, can be used as GPIO | analogue 3, GPIO |
| 6 | A4/SDA | Header pad 6 (the vendor numbers the header connector 1-28): ADC in, I2C SDA, can be used as GPIO | analogue 4, I2C SDA, GPIO |
| 7 | A5/SCL | Header pad 7 (the vendor numbers the header connector 1-28): ADC in, I2C SCL, can be used as GPIO | analogue 5, I2C SCL, GPIO |
| 8 | A6 | Header pad 8 (the vendor numbers the header connector 1-28): ADC in, can be used as GPIO | analogue 6, GPIO |
| 9 | D0 | Header pad 9 (the vendor numbers the header connector 1-28): GPIO, can be used as PWM | digital 0, PWM |
| 10 | D1 | Header pad 10 (the vendor numbers the header connector 1-28): GPIO, can be used as PWM | digital 1, PWM |
| 11 | D2/PWM | Header pad 11 (the vendor numbers the header connector 1-28): GPIO, can be used as PWM | digital 2, PWM |
| 12 | D3/PWM | Header pad 12 (the vendor numbers the header connector 1-28): GPIO, can be used as PWM | digital 3, PWM |
| 13 | D4/PWM | Header pad 13 (the vendor numbers the header connector 1-28): GPIO, can be used as PWM | digital 4, PWM |
| 14 | D5/PWM | Header pad 14 (the vendor numbers the header connector 1-28): GPIO, can be used as PWM | digital 5, PWM |
| 15 | D6 | Header pad 15 (the vendor numbers the header connector 1-28): GPIO, can be used as PWM | digital 6, PWM |
| 16 | D7 | Header pad 16 (the vendor numbers the header connector 1-28): GPIO, can be used as PWM | digital 7, PWM |
| 17 | D8/MOSI | Header pad 17 (the vendor numbers the header connector 1-28): SPI MOSI, can be used as GPIO, can be used as PWM | digital 8, SPI MOSI, GPIO, PWM |
| 18 | D9/SCK | Header pad 18 (the vendor numbers the header connector 1-28): SPI SCK, can be used as GPIO, can be used as PWM | digital 9, SPI SCK, GPIO, PWM |
| 19 | D10/MISO | Header pad 19 (the vendor numbers the header connector 1-28): SPI MISO, can be used as GPIO | digital 10, SPI MISO, GPIO |
| 20 | D11/SDA | Header pad 20 (the vendor numbers the header connector 1-28): I2C SDA, can be used as GPIO | digital 11, I2C SDA, GPIO |
| 21 | D12/SCL | Header pad 21 (the vendor numbers the header connector 1-28): I2C SCL, can be used as GPIO | digital 12, I2C SCL, GPIO |
| 22 | D13/RX | Header pad 22 (the vendor numbers the header connector 1-28): USART RX, can be used as GPIO | digital 13, USART RX, GPIO |
| 23 | D14/TX | Header pad 23 (the vendor numbers the header connector 1-28): USART TX, can be used as GPIO | digital 14, USART TX, GPIO |
| 24 | RESETN | Header pad 24 (the vendor numbers the header connector 1-28): Reset input | reset |
| 25 | GND | Header pad 25 (the vendor numbers the header connector 1-28): Power ground | ground |
| 26 | +3V3 | Header pad 26 (the vendor numbers the header connector 1-28): 3.3 V output (the datasheet's description cell is blank) | 3.3 V rail |
| 27 | VIN | Header pad 27 (the vendor numbers the header connector 1-28): VIN power input | power in |
| 28 | +5V | Header pad 28 (the vendor numbers the header connector 1-28): Power out; the datasheet's description cell reads 'Power Ground' here, which is a table error - see note | 5 V rail |
| 29 | VUSB | USB connector pad 1: Power supply input; output if the board is powered from VUSB on the header | power, USB |
| 30 | D- | USB connector pad 2: USB differential data - | USB |
| 31 | D+ | USB connector pad 3: USB differential data + | USB |
| 32 | ID | USB connector pad 4: Selects host/device functionality | USB |
| 33 | GND | USB connector pad 5: Supply ground | ground |
| 34 | +3V3 | Debug test pad 1 (3x2, 100 mil pitch, underside, 5 of 6 pads populated): Power out | 3.3 V rail |
| 35 | SWD | Debug test pad 2 (3x2, 100 mil pitch, underside, 5 of 6 pads populated): Single wire debug data | debug |
| 36 | RESETN | Debug test pad 3 (3x2, 100 mil pitch, underside, 5 of 6 pads populated): Processor reset input | reset |
| 37 | SWCLK | Debug test pad 4 (3x2, 100 mil pitch, underside, 5 of 6 pads populated): Single wire debug clock | debug |
| 38 | GND | Debug test pad 5 (3x2, 100 mil pitch, underside, 5 of 6 pads populated): Power ground | ground |
Buses
| Bus | Signals | Pins | Voltage | Note |
|---|---|---|---|---|
| I2C ×2 | SDA, SCL | A4/SDA, A5/SCL, D11/SDA, D12/SCL | 3.3 V V | Two I2C buses reach the header: the default Wire pair on A4 (SDA) and A5 (SCL), and a second on D11 (SDA) and D12 (SCL). Neither carries an on-board device address - the ATECC508 and W25Q16 hang off the processor's internal buses - so no address is published for either. |
| SPI ×1 | SCK, MISO, MOSI | D9/SCK, D10/MISO, D8/MOSI | 3.3 V V | The header SPI is the SAMD21 SERCOM pair on D8/D9/D10; the on-board W25Q16 flash has its own chip select on the internal SPI and is not on these pads. |
| UART ×1 | RX, TX | D13/RX, D14/TX | 3.3 V V | D13 is USART receive and D14 is USART transmit on the header. The USB port is a native SAMD21 USB peripheral, separate from this UART. |
Power
| Input | 4.5-5.5 V on VIN, or 4.8-5.5 V on USB/VUSB, or a single-cell Li-ion/LiPo on the on-board BQ24195L charger |
|---|---|
| Input range | VIN 4.5 V min, 5 V typ, 5.5 V max; VUSB 4.8 V min, 5 V typ, 5.5 V max; absolute maximum -0.3 to 5.5 V on both |
Outputs
| Rail | Rating | Note |
|---|---|---|
| 3V3 | 3.3 V V | LDO output rated 600 mA; 300 mA is available to a user application on header pad 26. |
| +5V | 5 V V | Header pad 28 is connected to the USB power input through a jumper - it is an input path, not a regulator output. |
Notes
Pin numbers 1-28 are the vendor's own numbering for the header connector, which the datasheet calls 'two 28 pin connectors'. This entry extends the same run to the USB connector (29-33) and the underside debug footprint (34-38), naming the connector and the vendor's pad number in every description so the offset cannot be confused with a header pad. The datasheet contradicts itself on the charger part number (BQ24195L on page 1, BQ24125L on page 3), prints 'Power Ground' as the description of the +5V pad, and labels its output-drive rows with a current unit - all three are recorded, none resolved. The datasheet's own pin tables are text, so the labels are machine-read, not vision-read.
AI context
Dense context for pasting into a model prompt — addresses, pinout, voltages, tolerances and the vendor's reference circuit.
PART: Arduino MKR WAN 1310, SKU ABX00029 - an MKR-form-factor board built on a Microchip ATSAMD21G18A (Arm Cortex-M0+ at up to 48 MHz, 256 kB flash, 32 kB SRAM) plus a Murata CMWX1ZZABZ LoRa module (STMicro STM32L0 Cortex-M0+ with 192 kB flash driving a Semtech SX1276 radio, +20 dBm RF TX), a Microchip ATECC508 crypto chip and a 16 Mbit W25Q16 SPI flash. Peripherals on the SAMD21: 12-channel DMA, 12-channel event system, 5x 16-bit timer/counter, 3x 24-bit timer/counter, 32-bit RTC, watchdog, CRC-32, full-speed USB host/device, 6x SERCOM (USART/I2C/SPI/LIN), two-channel I2S, 12-bit 350 ksps ADC (up to 16-bit with oversampling) and a 10-bit 350 ksps DAC. PINOUT: two headers in MKR form factor, which the vendor numbers as one 28-pin connector: pad 1 AREF, 2 A0/DAC0, 3 A1, 4 A2, 5 A3, 6 A4/SDA, 7 A5/SCL, 8 A6, 9 D0, 10 D1, 11 D2/PWM, 12 D3/PWM, 13 D4/PWM, 14 D5/PWM, 15 D6, 16 D7, 17 D8/MOSI, 18 D9/SCK, 19 D10/MISO, 20 D11/SDA, 21 D12/SCL, 22 D13/RX, 23 D14/TX, 24 RESETN, 25 GND, 26 +3V3, 27 VIN, 28 +5V. This entry numbers that header 1-28 as the vendor does, then the USB connector 29-33 (1 VUSB, 2 D-, 3 D+, 4 ID, 5 GND) and the underside debug footprint 34-38 (+3V3, SWD, RESETN, SWCLK, GND). The debug footprint is 3x2 on 100 mil pitch with only 5 pads populated. SUPPLY: power in on USB (Mini-B), on VIN or on VUSB. Recommended VIN 4.5 V min, 5 V typ, 5.5 V max; VUSB 4.8 V min, 5 V typ, 5.5 V max. Absolute maximum on both VIN and VUSB is -0.3 V to 5.5 V. On-board regulator chain is BQ24195L charger -> +3V8 -> 3.3 V LDO rated 600 mA, of which 300 mA is available to a user application on the 3V3 rail. Budget in the vendor's own power tree: SAMD21G18 30 mA, CMWX1ZZABZ 128 mA, ECC508 16 mA, W25Q16 30 mA, user application 300 mA. LOGIC AND LIMITS: 3.3 V I/O only and NOT 5 V tolerant - the vendor states a 5 V signal on a header pin will damage the board. Recommended input levels: VIH 1.815 V minimum, VIL 0.99 V maximum. The output rows of the same table are printed with a current unit (7 mA high, 10 mA low), so read them as drive-current limits, not voltages. Operating and storage temperature -40 to +85 C. INTERNAL WIRING: the SAMD21 reaches the CMWX1ZZABZ module over I2C on PA08/PA09 (NINA PB9/SDA1, PB8/SCL1) and over SPI on PA14/PA13/PA15/PA12 with PA27 as reset, PA28 as the module IRQ line and PB09 as boot0. The W25Q16 flash and the ATECC508 are on the processor's internal SPI and I2C, not on the header I2C, so no header device address is published and addresses is empty. TRAPS: (1) the 5V pin does not supply voltage - it is tied through a jumper to the USB power input. (2) The battery charger has a minimum charge current of 512 mA, so check the cell you attach can take it. (3) USB host mode works only when the board is powered from the VUSB pin and the jumper next to it is shorted. (4) USB feeds VIN through a Schottky diode into a DC-DC whose minimum input is 4.5 V, so the effective USB-supply floor rises to 4.8-4.96 V depending on load - above the connectors' own 4.8 V minimum. (5) Modifying the Murata module's open-source firmware requires recertification of the radio stack. (6) The datasheet names the charger BQ24195L on page 1 and BQ24125L on page 3; both strings are recorded and neither resolved. (7) Header pad 28 (+5V) carries the description 'Power Ground' in the vendor's own pin table, which contradicts its +5V function and is a table error.
Provenance
Every figure on this page was read from the 3 sources below and last checked on Oct 29, 2026.
- vendor Arduino Store - Arduino MKR WAN 1310 product page (SKU MKRWAN1310WANT, EUR 49.00 as measured; SAMD21, Murata CMWX1ZZABZ, ATECC508, 2 MByte SPI flash, 104 uA sleep, battery charger)
- datasheet Arduino MKR WAN 1310 user manual ABX00029 (header pinout table 3.2 pins 1-28, USB pinout 3.1, debug footprint 3.3, power tree, VIN 4.5-5.5 V, VUSB 4.8-5.5 V, 3V3 300 mA, VIH 1.815 V, VIL 0.99 V, 512 mA minimum charge current, the 5 V-intolerance warning and the SAMD21-to-CMWX1ZZABZ pin join)
- datasheet Microchip SAM D21/DA1 family data sheet DS40001882H - the ATSAMD21G18A's own data sheet; Microchip publishes no ATSAMD21G18A-only document