Muon from Boron or Argon migration guide

This is a preliminary guide and is subject to change.

Pictures are not the same scale

Hardware

Module style

The Argon and Boron are pin-based modules that can be installed in solderless breadboard for prototyping, can be installed in a socket on your custom board, or soldered directly to your board. The modules are in Adafruit Feather form-factor. There are male header pins on the bottom.

The Muon is a larger development module and contains a Particle M-SoM mounted in a M.2 NGFF socket, a power supply, and various peripheral chips.

There is an expansion connector on the top of the Muon, 40 pins (2x20), 0.1" (2.54mm) pitch. An expansion card can be mounted directly on top pf the Muon ("a HAT"), or can be connected to a solderless breadboard using Dupont wires or ribbon cable.

The expansion connector is mostly compatible with the Raspberry Pi expansion connector and some Pi HATs can be used on the Muon for expansion.

Device Inches Millimeters (mm)
Argon/Boron 0.9" x 2.0" 22.86mm x 50.8mm
Muon 2.2" x 3.35" 56mm x 85mm

You can use the Muon as a development module, or use it as a base for your you own product.

Dimensions

Dimensions in millimeters (mm)

Radios

Radio Argon Boron M-SoM Muon
Cellular
Wi-Fi 2.4 GHz
Wi-Fi 5 GHz
BLE
LoRa

Datasheets

Certification

When migrating to a new device, re-certification is typically required. If you are using the standard Particle antennas you often only need to complete the less expensive unintentional radiator testing of your completed assembly, however in some cases intentional radiator testing could be required.

Software differences

User firmware binary size

One major advantage is that user firmware binaries can be up to 2048 Kbytes, instead of 256 Kbytes on Gen 3 devices using Device OS 3.1.0 or later.

Available RAM

The Boron and Argon have around 80K of RAM available to user applications. The Muon and M-SoM has 3500K of available RAM.

Flash file system

There is a 2 MB flash file system for storing user data. This is the same size as the Boron, B-SoM, and Argon. The Tracker has a 4 MB flash file system.

USB Connector

The Argon and Boron have a USB Micro B connector.

The Muon has a USB C connector.

SWD/JTAG

The Muon has the same 10-pin (2x5) SWD/JTAG debugging connector as the Argon and Boron.

On the Muon and M-SoM, however, SWD is on the same pins as GPIO, so by default once user firmware boots, SWD is no longer available. This is the same as Gen 2 (STM32) but different than Gen 3 (nRF52840). Building a Debug build in Particle Workbench allows SWD to be used while user firmware is running, but you cannot use A4, A6, or D27 as GPIO when SWD is enabled in user firmware.

SWO (Serial Wire Output) is not supported on the RTL8722DM.

Pin Pin Name Description Interface MCU
43 A5 / D14 A5 Analog in, PWM, GPIO, shared with pin 53 SWCLK PB[3]
53 A5 / D14 A5 Analog in, PWM, GPIO, SWCLK, shared with pin 43 SWCLK PB[3]
55 D27 D27 GPIO, SWDIO (SWD_DATA), do not pull down at boot SWDIO PA[27]

LiPo Battery and LI+ pin

The Boron and Argon have a 2-pin JST-PH connector for a 3.7V LiPo battery. The standard Particle battery is 1800 mAh, but other batteries are available up to 6000 mAh in a similar but larger form-factor.

The Muon has a 3-pin JST-PH for a 3.7V LiPo battery with a battery pack temperature sensor.

The Boron uses a full PMIC (bq24195) and fuel gauge (MAX17043). By including these features on your base board you can provide more full-featured operation on battery power than the Argon does.

The Argon uses a Torex XC6208A42 LiPo charge controller.

The Muon uses the same PMIC and fuel gauge chips as the Boron.

Facing the plug on the battery side

EN pin

The Argon and Boron have EN pin which can shut down the Torex XC9258 3.3V regulator to power down the 3.3V supply to the Argon nRF52840 MCU and the ESP32 Wi-Fi coprocessor. A similar feature exists on the Boron, using a load switch to control the 3.3V power supply and the 3.7V cellular modem power supply.

This feature does not exist on the Muon.

Land pattern

The Muon is not intended to be placed on a carrier board, so doesn't have a land pattern, per se.

The expansion connector dimensions can be found in the Muon datasheet, but the expansion connector is on the top of the Muon and intended to be used with a small expansion card on top ("HAT") not with a bottom-mounted carrier, like the Argon or Boron.

GPIO

ADC pins
Boron Pin Name Boron GPIO Muon Pin Muon Pin Name Muon GPIO Raspberry Pi
A0 / D19 29 A0 / D19 GPIO5
A1 / D18 31 A1 / D18 GPIO6
A2 / D17 26 A2 / D17 GPIO7 (CE1)
A3 / D16        
A4 / D15        
A5 / D14 13 A5 / D14   GPIO27
    24 A6 / D29 GPIO8 (CE0)
D0 3 D0   GPIO2 (SDA)
D1 5 D1   GPIO3 (SCL)
D2 11 D2 GPIO17
    40 D20 GPIO21 (PCM_DOUT)
    38 D21 GPIO20 (PCM_DIN)
    16 D24 GPIO23
    18 D25 GPIO24
    35 D26 GPIO19 (PCM_FS)
D3 36 D3 GPIO16
D4 33 D4 GPIO13 (PWM1)
D5 32 D5 GPIO12 (PWM0)
D6 12 D6 GPIO18
D7        
D8 / WKP        
    7 IOEX_PA0 GPIO4 (GPCKL0)
    37 IOEX_PB7 GPIO26
MISO / D11 21 MISO / D11   GPIO9 (MISO)
MOSI / D12 19 MOSI / D12   GPIO10 (MOSI)
RX / D10 10 RX / D10 GPIO15 (RXD)
SCK / D13 23 SCK / D13   GPIO11 (SCLK)
TX / D09 8 TX / D9 GPIO14 (TXD)
  • Pin D8 is not available on the Muon expansion connector. It is used internally for the I/O expander interrupt.

ADC

ADC pins
Boron Pin Name Boron ADC Muon Pin Muon Pin Name Muon ADC Raspberry Pi
A0 / D19 29 A0 / D19 GPIO5
A1 / D18 31 A1 / D18 GPIO6
A2 / D17 26 A2 / D17 GPIO7 (CE1)
A3 / D16        
A4 / D15        
A5 / D14 13 A5 / D14 GPIO27
    24 A6 / D29 GPIO8 (CE0)
  • ADC inputs are single-ended and limited to 0 to 3.3V on both
  • Resolution is 12 bits on both

The ADCs on the M-SoM (RTL872x) have a lower impedance than other Particle device MCUs (nRF52, STM32F2xx). They require a stronger drive and this may cause issues when used with a voltage divider. This is particularly true for A7, which has an even lower impedance than other ADC inputs.

For signals that change slowly, such as NTC thermocouple resistance, you can add a 2.2 uF capacitor to the signal. For rapidly changing signals, a voltage follower IC can be used.

Serial

UART pins
Boron Pin Name Boron Serial Muon Pin Muon Pin Name Muon Serial Raspberry Pi
D2 Serial1 RTS 11 D2 Serial1 (RTS) GPIO17
    16 D24 Serial2 (TX) GPIO23
    18 D25 Serial2 (RX) GPIO24
D3 Serial1 CTS 36 D3 Serial1 (CTS) GPIO16
RX / D10 Serial1 RX 10 RX / D10 Serial1 (RX) GPIO15 (RXD)
TX / D09 Serial1 TX 8 TX / D9 Serial1 (TX) GPIO14 (TXD)
  • One additional UART serial port on the Muon/M-SoM

SPI

GPIO pins
Boron Pin Name Boron SPI Muon Pin Muon Pin Name Muon SPI Raspberry Pi
A1 / D18   31 A1 / D18 SPI2 (MISO) GPIO6
A2 / D17   26 A2 / D17 SPI2 (SCK) GPIO7 (CE1)
A5 / D14 SPI (SS) 13 A5 / D14   GPIO27
D2 SPI1 (SCK) 11 D2 SPI1 (SCK) GPIO17
D3 SPI1 (MOSI) 36 D3 SPI1 (SS) GPIO16
D4 SPI1 (MISO) 33 D4   GPIO13 (PWM1)
MISO / D11 SPI (MISO) 21 MISO / D11 SPI (MISO) GPIO9 (MISO)
MOSI / D12 SPI (MOSI) 19 MOSI / D12 SPI (MOSI) GPIO10 (MOSI)
RX / D10   10 RX / D10 SPI1 (MISO) GPIO15 (RXD)
SCK / D13 SPI (SCK) 23 SCK / D13 SPI (SCK) GPIO11 (SCLK)
TX / D09   8 TX / D9 SPI1 (MOSI) GPIO14 (TXD)

If using an expansion card that requires SPI, generally the following pins are used. The pins CE0 and CE1 are generally used for SPI chip select on standard Raspberry Pi expansion cards.

Pin Pin Name Description Interface M2 Pin MCU Raspberry Pi
19 MOSI / D12 D12 GPIO, PWM, SPI MOSI MOSI 52 PA[16] GPIO10 (MOSI)
21 MISO / D11 D11 GPIO, PWM, SPI MISO MISO 50 PA[17] GPIO9 (MISO)
23 SCK / D13 D13 GPIO, SPI SCK SCLK 54 PA[18] GPIO11 (SCLK)
24 A6 / D29 A6 Analog in, GPIO, PWM, M.2 eval PMIC INT CE0 45 PB[7] GPIO8 (CE0)
26 A2 / D17 A2 Analog in, GPIO CE1 35 PB[6] GPIO7 (CE1)

Expansion cards GPIO10 (MOSI), GPIO9 (MISO), and GPIO11(SCLK) can only be used for SPI. They cannot be used for SPI because the SPI bus is used for internal peripherals on the Muon. You can, however, use GPIO8 (CE0) and GPIO7 (CE1) as GPIO.

I2C

GPIO pins
Boron Pin Name Boron I2C Muon Pin Muon Pin Name Muon I2C Raspberry Pi
D0 Wire (SDA) 3 D0 Wire (SDA) GPIO2 (SDA)
D1 Wire (SCL) 5 D1 Wire (SCL) GPIO3 (SCL)
D6   12 D6 Wire1 (SCL) GPIO18
  • You can generally have many devices on a single I2C bus.
  • On the Muon, M-SoM, P2, and Photon 2, the only valid I2C clock speeds are CLOCK_SPEED_100KHZ and CLOCK_SPEED_400KHZ. Other speeds are not supported at this time.

If using an expansion card that requires I2C, generally the following pins are used on standard Raspberry Pi expansion cards.

Pin Pin Name Description Interface M2 Pin MCU Raspberry Pi
3 D0 D0 GPIO, I2C SDA SDA 22 PB[0] GPIO2 (SDA)
5 D1 D1 GPIO, I2C SCL SCL 20 PA[31] GPIO3 (SCL)

The Argon/Boron and M-SoM use D0/D1 for SDA/SCL.

Raspberry Pi GPIO2 and GPIO3 can only be used as I2C, not as GPIO, This is because the I2C is also used for peripherals on the Muon. You cannot use these I2C addresses on expansion cards as they will conflict with built-in peripherals.

I2C Address Peripheral
0x28 STUSB4500 USB-C power controller
0x36 MAX17043 Fuel Gauge
0x48 TMP112A temperature sensor
0x61 KG200Z LoRaWAN radio
0x69 AM1805 RTC/Watchdog
0x6B bq24195 PMIC

PWM

GPIO pins
Boron Pin Name Boron PWM Muon Pin Muon Pin Name Muon PWM Raspberry Pi
A0 / D19 29 A0 / D19 GPIO5
A1 / D18 31 A1 / D18 GPIO6
A2 / D17 26 A2 / D17   GPIO7 (CE1)
A3 / D16        
A4 / D15        
A5 / D14 13 A5 / D14 GPIO27
    24 A6 / D29 GPIO8 (CE0)
D2 11 D2   GPIO17
D3 36 D3   GPIO16
D4 33 D4 GPIO13 (PWM1)
D5 32 D5 GPIO12 (PWM0)
D6 12 D6 GPIO18
D7        
D8 / WKP        
MISO / D11   21 MISO / D11 GPIO9 (MISO)
MOSI / D12   19 MOSI / D12 GPIO10 (MOSI)
RX / D10   10 RX / D10 GPIO15 (RXD)
TX / D09   8 TX / D9 GPIO14 (TXD)

Boot mode pins

These pins have a special function at boot. Beware when using these pins as input as they can trigger special modes in the MCU.

Pin Pin Name Description M2 Pin MCU Raspberry Pi
13 A5 / D14 SWCLK. 40K pull-down at boot. 43 PB[3] GPIO27
15 D27 SWDIO. 40K pull-up at boot. Low at boot triggers MCU test mode. 55 PA[27] GPIO22
16 D24 Low at boot triggers ISP flash download 58 PA[7] GPIO23
18 D25 Goes high at boot 60 PA[8] GPIO24

NFC

The Muon and M-SoM do not support NFC.

The Boron and Argon support NFC Tag mode.

Sleep

  • In HIBERNATE sleep mode, the Muon/M-SoM can only be wakened via the WKP pin, but the Boron and Argon can be wakened by any pin.

  • In STOP and ULTRA_LOW_POWER sleep modes, the Muon, M-SoM, Boron, and Argon can be wakened by any pin.

  • In HIBERNATE sleep mode, the Muon/M-SoM puts OUTPUT pins into high-impedance state. The Boron and Argon preserve the digital level.

  • In STOP and ULTRA_LOW_POWER sleep modes, the Muon, M-SoM, Boron, and Argon preserve the digital output

  • In HIBERNATE sleep mode, on the Muon/M-SoM, pin D21 does not maintain INPUT_PULLUP or INPUT_PULLDOWN while asleep.

Pin Pin Name Description Interface MCU
17 D21 D21 GPIO, I2S RX No internal pull up or pull down in HIBERNATE sleep mode. PA[0]
36 TX / D9 Serial TX, PWM, GPIO, SPI1 MOSI, I2S MCLK Pin can wake from HIBERNATE sleep PA[12]
38 RX / D10 Serial RX, PWM, GPIO, SPI1 MISO Pin can wake from HIBERNATE sleep PA[13]
40 D3 D3 GPIO, Serial1 CTS flow control (optional), SPI1 SS Pin can wake from HIBERNATE sleep PA[15]
42 D2 D2 GPIO, Serial RTS flow control (optional), SPI1 SCK Pin can wake from HIBERNATE sleep PA[14]
47 A7 / WKP A7 Analog In, WKP, GPIO D28 Pin can wake from HIBERNATE sleep PA[20]
48 D8 D8 GPIO, SPI SS Pin can wake from HIBERNATE sleep PA[19]
50 MISO / D11 D11 GPIO, PWM, SPI MISO Pin can wake from HIBERNATE sleep PA[17]
52 MOSI / D12 D12 GPIO, PWM, SPI MOSI Pin can wake from HIBERNATE sleep PA[16]
54 SCK / D13 D13 GPIO, SPI SCK Pin can wake from HIBERNATE sleep PA[18]

Full comparison

3V3

Boron Muon
  Pin Name 3V3 3V3
Description Regulated 3.3V DC output, maximum load 1000 mA 3.3V power to expansion card

5V

Added to Muon
Pin Name 5V
Description 5V power to expansion card

A0

Boron Muon
  Pin Name A0 A0
  Pin Alternate Name D19 D19
  Description A0 Analog in, GPIO, PWM A0 Analog in, GPIO, PWM
  Supports digitalRead Yes Yes
  Supports digitalWrite Yes Yes
  Supports analogRead Yes Yes
  Supports analogWrite (PWM) Yes Yes
Supports tone A0, A1, A2, and A3 must have the same frequency. Yes
Supports attachInterrupt Yes. You can only have 8 active interrupt pins. Yes
Internal pull resistance 13K 42K

A1

Boron Muon
  Pin Name A1 A1
  Pin Alternate Name D18 D18
  Description A1 Analog in, GPIO, PWM A1 Analog in, GPIO, PWM
  Supports digitalRead Yes Yes
  Supports digitalWrite Yes Yes
  Supports analogRead Yes Yes
  Supports analogWrite (PWM) Yes Yes
Supports tone A0, A1, A2, and A3 must have the same frequency. Yes
SPI interface n/a MISO. Use SPI2 object.
Supports attachInterrupt Yes. You can only have 8 active interrupt pins. Yes
Internal pull resistance 13K ???

A2

Boron Muon
  Pin Name A2 A2
  Pin Alternate Name D17 D17
Description A2 Analog in, GPIO, PWM A2 Analog in, GPIO
  Supports digitalRead Yes Yes
  Supports digitalWrite Yes Yes
  Supports analogRead Yes Yes
Supports analogWrite (PWM) Yes No
Supports tone A0, A1, A2, and A3 must have the same frequency. No
SPI interface n/a SCK. Use SPI2 object.
Supports attachInterrupt Yes. You can only have 8 active interrupt pins. Yes
Internal pull resistance 13K 22K

A3

Removed from Boron
Pin Name A3
Pin Alternate Name D16
Description A3 Analog in, GPIO, PWM
Supports digitalRead Yes
Supports digitalWrite Yes
Supports analogRead Yes
Supports analogWrite (PWM) Yes
Supports tone A0, A1, A2, and A3 must have the same frequency.
Supports attachInterrupt Yes. You can only have 8 active interrupt pins.
Internal pull resistance 13K

A4

Removed from Boron
Pin Name A4
Pin Alternate Name D15
Description A4 Analog in, GPIO, PWM
Supports digitalRead Yes
Supports digitalWrite Yes
Supports analogRead Yes
Supports analogWrite (PWM) Yes
Supports tone A4, A5, D2, and D3 must have the same frequency.
Supports attachInterrupt Yes. You can only have 8 active interrupt pins.
Internal pull resistance 13K

A5

Boron Muon
  Pin Name A5 A5
  Pin Alternate Name D14 D14
Description A5 Analog in, GPIO, PWM, SPI SS A5 Analog in, PWM, GPIO, shared with pin 53
Supports digitalRead Yes n/a
Supports digitalWrite Yes n/a
  Supports analogRead Yes Yes
  Supports analogWrite (PWM) Yes Yes
Supports tone A4, A5, D2, and D3 must have the same frequency. Yes
SPI interface SS. Use SPI object. This is only the default SS/CS pin, you can use any GPIO instead. n/a
Supports attachInterrupt Yes. You can only have 8 active interrupt pins. n/a
Internal pull resistance 13K ???
SWD interface n/a SWCLK. 40K pull-down at boot.
Signal used at boot n/a SWCLK. 40K pull-down at boot.

A6

Added to Muon
Pin Name A6
Pin Alternate Name D29
Description A6 Analog in, GPIO, PWM, M.2 eval PMIC INT
Supports digitalRead Yes
Supports digitalWrite Yes
Supports analogRead Yes
Supports analogWrite (PWM) Yes
Supports tone Yes
Supports attachInterrupt Yes
Internal pull resistance ???

D0

Boron Muon
  Pin Name D0 D0
Description I2C SDA, GPIO D0 GPIO, I2C SDA
Supports digitalRead Yes n/a
Supports digitalWrite Yes n/a
I2C interface SDA. Use Wire object. SDA. Use Wire object. Use 1.5K to 10K external pull-up resistor.
Supports attachInterrupt Yes. You can only have 8 active interrupt pins. n/a
Internal pull resistance 13K ???

D1

Boron Muon
  Pin Name D1 D1
Description I2C SCL, GPIO D1 GPIO, I2C SCL
Supports digitalRead Yes n/a
Supports digitalWrite Yes n/a
I2C interface SCL. Use Wire object. SCL. Use Wire object. Use 1.5K to 10K external pull-up resistor.
Supports attachInterrupt Yes. You can only have 8 active interrupt pins. n/a
Internal pull resistance 13K ???

D2

Boron Muon
  Pin Name D2 D2
Description SPI1 SCK, Serial1 RTS, GPIO, PWM D2 GPIO, Serial RTS flow control (optional), SPI1 SCK
  Supports digitalRead Yes Yes
  Supports digitalWrite Yes Yes
Supports analogWrite (PWM) Yes No
Supports tone A4, A5, D2, and D3 must have the same frequency. No
  UART serial RTS. Use Serial1 object. RTS. Use Serial1 object.
  SPI interface SCK. Use SPI1 object. SCK. Use SPI1 object.
Supports attachInterrupt Yes. You can only have 8 active interrupt pins. Yes
Internal pull resistance 13K ???

D20

Added to Muon
Pin Name D20
Description D20 GPIO, I2S TX
Supports digitalRead Yes
Supports digitalWrite Yes
Supports attachInterrupt Yes
I2S interface I2S TX
Internal pull resistance ???

D21

Added to Muon
Pin Name D21
Description D21 GPIO, I2S RX
Supports digitalRead Yes
Supports digitalWrite Yes
Supports attachInterrupt Yes
I2S interface I2S RX
Internal pull resistance 22K. No internal pull up or pull down in HIBERNATE sleep mode.

D22

Added to Muon
Pin Name D22
Description D22 GPIO
Internal pull resistance ???

D24

Added to Muon
Pin Name D24
Description D24 GPIO, Serial2 TX, do not pull down at boot
Supports digitalRead Yes
Supports digitalWrite Yes
UART serial TX. Use Serial2 object.
Supports attachInterrupt Yes
Internal pull resistance 42K
Signal used at boot Low at boot triggers ISP flash download

D25

Added to Muon
Pin Name D25
Description GPIO25, Serial2 RX
Supports digitalRead Yes
Supports digitalWrite Yes
UART serial RX. Use Serial2 object.
Supports attachInterrupt Yes
Internal pull resistance 42K
Signal used at boot Goes high at boot

D26

Added to Muon
Pin Name D26
Description D26 GPIO, I2S WS
Supports digitalRead Yes
Supports digitalWrite Yes
Supports attachInterrupt Yes
I2S interface I2S WS
Internal pull resistance ???

D27

Added to Muon
Pin Name D27
Description D27 GPIO, SWDIO (SWD_DATA), do not pull down at boot
Internal pull resistance 42K
SWD interface SWDIO. 40K pull-up at boot.
Signal used at boot SWDIO. 40K pull-up at boot. Low at boot triggers MCU test mode.

D3

Boron Muon
  Pin Name D3 D3
Description SPI1 MOSI, Serial1 CTS, PWM, GPIO D3 GPIO, Serial1 CTS flow control (optional), SPI1 SS
  Supports digitalRead Yes Yes
  Supports digitalWrite Yes Yes
Supports analogWrite (PWM) Yes No
Supports tone A4, A5, D2, and D3 must have the same frequency. No
  UART serial CTS. Use Serial1 object. CTS. Use Serial1 object.
SPI interface MOSI. Use SPI1 object. SS. Use SPI1 object.
Supports attachInterrupt Yes. You can only have 8 active interrupt pins. Yes
Internal pull resistance 13K ???

D4

Boron Muon
  Pin Name D4 D4
Description SPI1 MISO, PWM, GPIO D4 GPIO, PWM
  Supports digitalRead Yes Yes
  Supports digitalWrite Yes Yes
  Supports analogWrite (PWM) Yes Yes
Supports tone D4, D5, D6, and D7 must have the same frequency. Yes
SPI interface MISO. Use SPI1 object. n/a
Supports attachInterrupt Yes. You can only have 8 active interrupt pins. Yes
Internal pull resistance 13K ???

D5

Boron Muon
  Pin Name D5 D5
Description PWM, GPIO D5 GPIO, PWM, I2S TX
  Supports digitalRead Yes Yes
  Supports digitalWrite Yes Yes
  Supports analogWrite (PWM) Yes Yes
Supports tone D4, D5, D6, and D7 must have the same frequency. Yes
Supports attachInterrupt Yes. You can only have 8 active interrupt pins. Yes
I2S interface n/a I2S TX
Internal pull resistance 13K ???

D6

Boron Muon
  Pin Name D6 D6
Description PWM, GPIO D6 GPIO, PWM, I2S CLK
  Supports digitalRead Yes Yes
  Supports digitalWrite Yes Yes
  Supports analogWrite (PWM) Yes Yes
Supports tone D4, D5, D6, and D7 must have the same frequency. Yes
I2C interface n/a SCL. Use Wire1 object. Use 1.5K to 10K external pull-up resistor.
Supports attachInterrupt Yes. You can only have 8 active interrupt pins. Yes
I2S interface n/a I2S CLK
Internal pull resistance 13K ???

D7

Removed from Boron
Pin Name D7
Description PWM, GPIO
Supports digitalRead Yes
Supports digitalWrite Yes
Supports analogWrite (PWM) PWM is shared with the RGB LED, you can specify a different duty cycle but should not change the frequency.
Supports attachInterrupt Yes. You can only have 8 active interrupt pins.
Internal pull resistance 13K

D8

Removed from Boron
Pin Name D8
Pin Alternate Name WKP
Description GPIO, PWM
Supports digitalRead Yes
Supports digitalWrite Yes
Supports analogWrite (PWM) Yes
Supports tone D4, D5, D6, and D7 must have the same frequency.
Supports attachInterrupt Yes. You can only have 8 active interrupt pins.
Internal pull resistance 13K

EN

Removed from Boron
Pin Name EN
Description Power supply enable. Connect to GND to power down. Has internal weak (100K) pull-up.

GND

Boron Muon
  Pin Name GND GND
Description Ground. Ground

IOEX_PA0

Added to Muon
Pin Name IOEX_PA0
Description n/a
Supports digitalRead Yes
Supports digitalWrite Yes

IOEX_PB7

Added to Muon
Pin Name IOEX_PB7
Description n/a
Supports digitalRead Yes
Supports digitalWrite Yes

LI+

Removed from Boron
Pin Name LI+
Description Connected to JST PH LiPo battery connector. 3.7V in or out.

MISO

Boron Muon
  Pin Name MISO MISO
  Pin Alternate Name D11 D11
Description SPI MISO, GPIO D11 GPIO, PWM, SPI MISO
Supports digitalRead Yes n/a
Supports digitalWrite Yes n/a
Supports analogWrite (PWM) No Yes
Supports tone No Yes
  SPI interface MISO. Use SPI object. MISO. Use SPI object.
Supports attachInterrupt Yes. You can only have 8 active interrupt pins. n/a
Internal pull resistance 13K 2.1K

MODE

Removed from Boron
Pin Name MODE
Description MODE button, has internal pull-up

MOSI

Boron Muon
  Pin Name MOSI MOSI
  Pin Alternate Name D12 D12
Description SPI MOSI, GPIO D12 GPIO, PWM, SPI MOSI
Supports digitalRead Yes n/a
Supports digitalWrite Yes n/a
Supports analogWrite (PWM) No Yes
Supports tone No Yes
  SPI interface MOSI. Use SPI object. MOSI. Use SPI object.
Supports attachInterrupt Yes. You can only have 8 active interrupt pins. n/a
Internal pull resistance 13K 2.1K

NC27

Added to Muon
Pin Name NC27
Description n/a

NC28

Added to Muon
Pin Name NC28
Description n/a

RST

Removed from Boron
Pin Name RST
Description Hardware reset. Pull low to reset; can leave unconnected in normal operation.

RX

Boron Muon
  Pin Name RX RX
  Pin Alternate Name D10 D10
Description Serial RX, GPIO Serial RX, PWM, GPIO, SPI1 MISO
  Supports digitalRead Yes Yes
  Supports digitalWrite Yes Yes
Supports analogWrite (PWM) No Yes
Supports tone No Yes
  UART serial RX. Use Serial1 object. RX. Use Serial1 object.
SPI interface n/a MISO. Use SPI1 object.
Supports attachInterrupt Yes. You can only have 8 active interrupt pins. Yes
Internal pull resistance 13K 2.1K

SCK

Boron Muon
  Pin Name SCK SCK
  Pin Alternate Name D13 D13
Description SPI SCK, GPIO D13 GPIO, SPI SCK
Supports digitalRead Yes n/a
Supports digitalWrite Yes n/a
  SPI interface SCK. Use SPI object. SCK. Use SPI object.
Supports attachInterrupt Yes. You can only have 8 active interrupt pins. n/a
Internal pull resistance 13K 2.1K

TX

Boron Muon
  Pin Name TX TX
Pin Alternate Name D09 D9
Description Serial TX, GPIO Serial TX, PWM, GPIO, SPI1 MOSI, I2S MCLK
  Supports digitalRead Yes Yes
  Supports digitalWrite Yes Yes
Supports analogWrite (PWM) No Yes
Supports tone No Yes
  UART serial TX. Use Serial1 object. TX. Use Serial1 object.
SPI interface n/a MOSI. Use SPI1 object.
Supports attachInterrupt Yes. You can only have 8 active interrupt pins. Yes
I2S interface n/a I2S MCLK
Internal pull resistance 13K 2.1K

VUSB

Removed from Boron
Pin Name VUSB
Description Power out (when powered by USB) 5 VDC at 1A maximum. Power in with limitations.
Input is 5V Tolerant Yes

Software

Wi-Fi configuration

Since the Boron (cellular) does not have Wi-Fi support, if you wish to use Wi-Fi on the Muon/M-SoM you will need to provide a way to configure it. Wi-Fi setup works the same as the P2, Photon 2, and Argon, and uses BLE. See Wi-Fi setup options for more information.

User firmware binary size

One major advantage of the Muon/M-SoM is that user firmware binaries can be up to 2048 Kbytes.

On the B-SoM (Device OS 3.1 and later), it's 256 Kbytes, or 128 Kbytes for older version of Device OS.

Platform ID

The Platform ID of the msom (35, PLATFORM_MSOM) is different from that of the Boron (13) because of the vastly different hardware. Note that Muon and M-SoM share a platform ID.

If you have a product based on the Boron, you will need to create a separate product for devices using the M-SoM. While you may be able to use the same source code to build your application, the firmware binaries uploaded to the console will be different, so they need to be separate products. This generally does not affect billing as only the number of devices, not the number of products, is counted toward your plan limits.

Third-party libraries

Most third-party libraries are believed to be compatible. The exceptions include:

  • Libraries for MCU-specific features (such as ADC DMA)
  • Libraries that are hardcoded to support only certain platforms by their PLATFORM_ID
  • Libraries that manipulate GPIO at high speeds or are timing-dependent

DS18B20 (1-Wire temperature sensor)

  • Not compatible
  • OneWire library requires high-speed GPIO support
  • Can use DS2482 I2C to 1-Wire bridge chip instead
  • SHT30 sensors (I2C) may be an alternative in some applications

FastLED

  • Not compatible.
  • In theory the library could be modified to use the same technique as the NeoPixel library.

NeoPixel (WS2812, WS2812B, and WS2813)

OneWire

  • Not compatible
  • OneWire library requires high-speed GPIO support
  • Can use DS2482 I2C to OneWire bridge instead

DHT22 and DHT11 (temperature and humidity sensor)

  • Not compatible, requires high-speed GPIO support
  • Using an I2C temperature and humidity sensor like the SHT3x is recommended instead

SHT1x (temperature and humidity sensor)

  • Not compatible, requires high-speed GPIO support
  • SHT3x using I2C is recommended

SparkIntervalTimer

  • Not compatible at this time
  • Requires hardware timer support from user firmware

Revision history

Revision Date Author Comments
pre 2024-02-05 RK Preliminary version
2024-05-08 RK Update for schematic 0.4R1
2024-05-14 RK Update for schematic 0.4R4
2024-05-21 RK Update for dimensions
2024-08-04 RK Pinmap 0.05
1 2024-10-22 RK Initial release