Muon from Boron or Argon migration guide

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.

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

Dimensions in millimeters (mm)

Radios

Datasheets

• Muon datasheet
• M-SoM datasheet
• Boron BRN404X datasheet
• Boron datasheet
• B-Series evaluation board

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.

You must use an actual USB-C port or USB-C power adapter to power the Muon by USB.

A USB-A to USB-C cable will not power the Muon or charge the battery

The reason is that the Muon uses USB-C PD to change the USB port voltage to 9V and request enough current to power the Muon.

When using a USB-2 or USB-3 port with USB-A to USB-C adapter cable, the USB port voltage cannot be changed and the port will not be able to power the Muon.

Also beware of some wall adapters that have a USB-C cable, but do not support USB-C PD. Some of these are advertised as Raspberry Pi power adapters, which only support 5V and cannot be used to power the Muon.

See Muon USB Power for more information.

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.

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

• Pin D8 is not available on the Muon expansion connector. It is used internally for the I/O expander interrupt.

ADC

• 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

• One additional UART serial port on the Muon/M-SoM

SPI

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.

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

• 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.

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.

PWM

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.

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.

Full comparison

3V3

5V

A0

A1

A2

A3

A4

A5

A6

D0

D1

D2

D20

D21

D22

D24

D25

D26

D27

D3

D4

D5

D6

D7

D8

EN

GND

IOEX_PA0

IOEX_PB7

LI+

MISO

MODE

MOSI

NC27

NC28

RST

RX

SCK

TX

VUSB

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)

• Requires Device OS 5.3.2 or later and Particle-NeoPixel version 1.0.3.

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