Monitor One datasheet

Pre-release draft 2022-10-27 for review only. Do not distribute or share this URL!

This is an preliminary pre-release datasheet and the contents are subject to change.

Front view

The pictures in this preliminary datasheet are of a pre-release unit. The production units will be a different color, and may have other minor differences.

The Monitor One is an off-the-shelf complete design, like the Tracker One. The Monitor One is in a larger IP67 waterproof enclosure with room inside for expansion cards and additional connectors, allowing it to be used in more custom scenarios than the Tracker One.

  • Ready to go with rugged IP67-rated enclosure with room inside for expansion cards and additional connectors.
  • Flexible power supply to easily add asset tracking to most devices with a 6 - 90 VDC power input and a large 18650 LiPo battery pack.
  • Internal or external antennas for cellular and GNSS.
  • Temperature sensors within the enclosure, and also a battery pack temperature sensor.
  • Expansion cards allow for custom features.
  • RGB LEDs for system status, and two user RGB LEDs for your own use, visible from outside the enclosure.
  • User button, waterproof and accessible from outside the enclosure.

Block diagram

Block diagram

Details about the Tracker SoM that is contained within the Monitor One can be found in the Tracker SoM Datasheet.

External features

External features
Label Feature
1 System RGB LED
2 GNSS antenna (internal)
3 Cellular antenna (internal)
4 External connectors (on bottom)
5 Magnetic, bolt-down, or strap down mounting bracket
6 User RGB LEDs (2)
7 User button (externally accessible)
8 Wi-Fi geolocation antenna (internal)

User button

A waterproof button is available from the outside of the enclosure.

  • Long press (10 seconds) resets the device (as if the RESET button was pressed)
  • Shorter press and multiple press can be handled by your user firmware for your own features

User LEDs (2)

  • There are two small RGB LEDs visible from the outside on the side of the unit, next to the user button.
  • You can program custom colors, blinking, and fade effects for each LED from your user firmware.
  • LEDs are controlled by a ADP8866 I2C LED controller.

Connectors

Bottom Connectors

The bottom plate of the Monitor One can be customized with different connectors for your application.

Label Feature
1 Cellular antenna (SMA)
2 M12 connector (8-pin)
3 M12 connector (4-pin)
4 GNSS antenna (SMA)
5 Mounting plate attachment screw

By default the Monitor One uses the internal cellular and GNSS antennas, but can be switched to using the external connectors inside the enclosure.

Mounting

The Monitor One is intended to be mounted in the orientation shown at the top of the page, with the connectors facing down. You can also mount it with the mounting plate facing down as the GNSS antenna is angled to allow it to work in either orientation.

When using external cellular and GNSS antennas you can orient the Monitor One in any direction.

The mounting plate contains two magnets that allow it to be easily mounted on a metal surface, or to a metal plate affixed to a non-metal surface, such as the wood post shown above.

Back View

The mounting plate is removable from the back of the unit after removing the screw on the bottom, near the expansion connectors.

Once removed, you can screw or bolt the mounting plate to a surface and reattach the Monitor One. This is good for rough conditions and to help prevent theft.

Dimensions Metric SAE
Top, width between mounting holes 28 mm 1 3/32"
Bottom, width between mounting holes 46 mm 1 13/16"
Height between mounting holes 140 mm 5 1/2"
Mounting bracket holes
Dimensions Metric SAE
Bolt/screw head hole diameter 12.46 mm 31/64"
Bolt/screw head maximum height 4.0 mm 5/32"
Bolt/screw hole diameter 4.33 mm 11/64"
Bolt/screw shaft to surface 3.65 mm 9/64"
Recommended bolt M4 #8
Mounting bracket screw hole dimensions

When mounting using a strap, the strap will hold the mounting bracket against a surface and is sandwiched between the mounting bracket and the Monitor One enclosure.

Dimensions Metric SAE
Maximum strap width 15 mm 19/32"
Strap mounting dimensions

Internal features

Base board features
Label Feature
1 MCU USB Connector (Micro B)
2 User RGB LEDs (2, externally visible)
3 User Button (externally accessible)
4 System RGB LED (externally visible)
5 GNSS antenna (internal, optional)
6 GNSS antenna U.FL connector
7 Cellular antenna (internal)
8 Cellular antenna U.FL connector
9 Expansion card headers (2)
10 SWD debugging connector
11 Wi-Fi geolocation antenna U.FL connector
12 MODE and SETUP buttons
13 VIN connector
14 Expansion card to external connector cable
15 LiPo battery connector
16 Cellular antenna SMA connector (external)
17 Expansion card external connector #1 (M12, 8-pin)
18 Expansion card external connector #2 (M12)
19 GNSS antenna SMA connector (external)
20 Tracker SoM module
21 Wi-Fi geolocation antenna (internal, not pictured)

Expansion card interface

Tracker M is designed with easy-to-use expansion headers and an enclosure with sufficient space inside for an expansion card, and for additional expansion connector through the wall of enclosure.

  • Expansion card size: 50mm x 90mm (approximately 2" x 3.5")
  • Connectors: 24-pin 0.1" headers (two, one on each long side)
  • Male header pins on the bottom of expansion card
  • Attachment: 4 screws to standoffs (M3 screw recommended)

Pre-built expansion cards will be available, including a prototyping breadboard expansion card. You can also design and fabricate your own.

Prototyping expansion card

Expansion card pinout

Expansion card pinout

Expansion card dimensions

Expansion card dimensions

Expansion card location

Expansion card location
Label Feature
14 Expansion card to external connector cable (M8 to PHR8)
17 Expansion card external connector #1 (M12, 8-pin)
22 Location of expansion card (green outline)

The enclosure typically has a panel-mount M12 8 pin female connector in location 17 in the picture above. This is connected via a short cable to a PHR-8 female connector that attaches to your expansion card. The picture above shows the cable but a board is not installed in the picture.

The functions of the pins on the M12 8-pin connector are dependent on your base board, but the following pinouts are recommended:

Conn P1 (M12) Conn P2 (PHR-8) Function
1 8
2 1 VIN
3 3 CAN_P
4 4 CAN_N
5 5
6 6
7 7
8 2 Ground
Round Rectangular
Enclosure Expansion Card
M8 to PHR-8 cable

Note: wire color may vary from this graphic.

  • Cable length: 75mm
  • Wire gauge: 24 AWG
  • M12 8-pin connector, A-coded

M12 connectors

The standard M12 connectors are IP67 waterproof (connected or not), 12 mm in diameter, and have 8 pins or 4 pins. However, M12 connectors are available from 2 pin to 17 pins. The connectors with smaller numbers of pins often have higher voltage and current ratings.

The panel-mount 8-pin connector on the Monitor One is female, with the following pinout:

M12 connector

The panel mount M12 8-pin connector fits in the following hole in the enclosure:

M12 hole

GPIO

Pin Name Description SoM Pin MCU
TSOM_A7 / D7 A7 Analog in, GPIO D7, PWM, SPI SS, WKP 38 P0.05
TSOM_A6 / D6 A6 Analog in, GPIO D6, PWM, SPI (SCK) 39 P0.04
TSOM_A5 / D5 A5 Analog in, GPIO D5, PWM, SPI MISO 40 P0.29
TSOM_A4 / D4 A4 Analog in, GPIO D4, PWM, SPI MOSI 41 P0.29
TSOM_A2_BUTTON / D2 External user button, A2 Analog in, GPIO D2, PWM 57 P0.28
TSOM_A3_BATT_TEMP / D3 Battery temperature sensor, A3 Analog in, GPIO D3, PWM 58 P0.30
RX / D9 Serial1 RX, GPIO D9, PWM, Wire3 SDA 71 P0.08
TX / D8 Serial1 TX, GPIO D8, PWM, Wire3 SCL 72 P0.06
  • On the Monitor One, pins A0 and A1 are used in I2C mode by the user RGB LED temperature sensor. Pins A0 and A1 cannot be used as GPIO.
  • On the Monitor One, you should not use A2 and A3 as GPIO or analog inputs as they are used by the external user button and battery temperature thermistor.
  • All GPIO are 3.3V and are not 5V tolerant.

ADC

Pin Name Description Interface SoM Pin MCU
TSOM_A7 / D7 A7 Analog in, GPIO D7, PWM, SPI SS, WKP ADC3 38 P0.05
TSOM_A6 / D6 A6 Analog in, GPIO D6, PWM, SPI (SCK) ADC2 39 P0.04
TSOM_A5 / D5 A5 Analog in, GPIO D5, PWM, SPI MISO ADC5 40 P0.29
TSOM_A4 / D4 A4 Analog in, GPIO D4, PWM, SPI MOSI ADC7 41 P0.29
TSOM_A2_BUTTON / D2 External user button, A2 Analog in, GPIO D2, PWM ADC4 57 P0.28
TSOM_A3_BATT_TEMP / D3 Battery temperature sensor, A3 Analog in, GPIO D3, PWM ADC6 58 P0.30
  • On the Monitor One, you should not use A2 and A3 as analog inputs as they are used by the external user button and battery temperature thermistor.

SPI

Pin Name Description Interface SoM Pin MCU
TSOM_A6 / D6 A6 Analog in, GPIO D6, PWM, SPI (SCK) SPI (SCK) 39 P0.04
TSOM_A5 / D5 A5 Analog in, GPIO D5, PWM, SPI MISO SPI (MISO) 40 P0.29
TSOM_A4 / D4 A4 Analog in, GPIO D4, PWM, SPI MOSI SPI (MOSI) 41 P0.29
  • Any available GPIO can be used as a SPI CS/SS pin.

I2C

Pin Name Description Interface SoM Pin MCU
TSOM_A0_SDA / D0 Wire SDA Wire (SDA) 55 P0.03
TSOM_A1_SCL / D1 Wire SCL Wire (SCL) 56 P0.02
RX / D9 Serial1 RX, GPIO D9, PWM, Wire3 SDA Wire3 (SDA) 71 P0.08
TX / D8 Serial1 TX, GPIO D8, PWM, Wire3 SCL Wire3 (SCL) 72 P0.06
  • On the Monitor One, pins A0 and A1 are used in I2C mode by the user RGB LED and temperature sensor. Pins A0 and A1 cannot be used as GPIO.
  • On the Monitor One (and Tracker SoM), Wire and Wire3 are two different I2C peripherals and can be used at the same time.
  • On the Monitor One (and Tracker SoM), Wire3 and Serial1 share the same pins and only one can be used at a time.
  • I2C is 3.3V only and is not 5V tolerant.
  • There are 4.7K pull-up resistors on TSOM_A0_SDA and TSOM_A1_SCL to 3.3V on the base board.

Serial (UART)

Pin Name Description Interface SoM Pin MCU
RX / D9 Serial1 RX, GPIO D9, PWM, Wire3 SDA Serial1 RX 71 P0.08
TX / D8 Serial1 TX, GPIO D8, PWM, Wire3 SCL Serial1 TX 72 P0.06
  • On the Monitor One (and Tracker SoM), Wire3 and Serial1 share the same pins and only one can be used at a time.
  • Hardware flow control is not available on the Monitor One.
  • Serial pins are 3.3V only and are not 5V tolerant.
  • Additional interface chips are required for other serial standards such as RS232 and RS485.

PWM

Pin Name Description Interface SoM Pin MCU
TSOM_A7 / D7 A7 Analog in, GPIO D7, PWM, SPI SS, WKP PWM1 38 P0.05
TSOM_A6 / D6 A6 Analog in, GPIO D6, PWM, SPI (SCK) PWM1 39 P0.04
TSOM_A5 / D5 A5 Analog in, GPIO D5, PWM, SPI MISO PWM1 40 P0.29
TSOM_A4 / D4 A4 Analog in, GPIO D4, PWM, SPI MOSI PWM1 41 P0.29
TSOM_A2_BUTTON / D2 External user button, A2 Analog in, GPIO D2, PWM PWM0 57 P0.28
TSOM_A3_BATT_TEMP / D3 Battery temperature sensor, A3 Analog in, GPIO D3, PWM PWM0 58 P0.30
RX / D9 Serial1 RX, GPIO D9, PWM, Wire3 SDA PWM2 71 P0.08
TX / D8 Serial1 TX, GPIO D8, PWM, Wire3 SCL PWM2 72 P0.06
  • On the Monitor One, you should not use A2 and A3 as PWM outputs as they are used by the external user button and battery temperature thermistor.
  • All pins on the same hardware timer (PWM0, PWM1, or PWM2) must share the same frequency but can have different duty cycles.

CAN

Pin Name Description Interface SoM Pin
CAN_N CAN Data- or CANL CAN_N 64
CAN_P CAN Data+ or CANH CAN_P 65
CAN_5V 5V power out, 0.8A maximum. Can be controlled by software. CAN_5V 66

The CAN transceiver is included on the Tracker SoM. However if you implement CAN on your expansion card, you will probably want to add protection circuitry. This circuit is present on the Monitor One CAN expansion card and also on the Tracker One.

CAN schematic

Note that the two 60.4 ohm resistors are DNP (do not populate). If populated, these provide the 120 ohm CAN termination, if you need it in your design.

All expansion card pins

Pin Pin Name Description MCU
1 GNSS_PULSE GNSS time pulse output. Can be used for a GPS fix LED.  
2 NC    
3 NC    
4 NC    
5 NC    
6 NC    
7 NC    
8 NC    
9 NFC2_VIN_EN VIN enable P0.10
10 NFC1_PERIPH_INT Peripheral interrupt (active low) P0.09
11 TSOM_MODE MODE button (active low) P1.13
12 TSOM_RESET RESET button (active low) P0.08
13 TSOM_A7 / D7 A7 Analog in, GPIO D7, PWM, SPI SS, WKP P0.05
14 TSOM_A6 / D6 A6 Analog in, GPIO D6, PWM, SPI (SCK) P0.04
15 TSOM_A5 / D5 A5 Analog in, GPIO D5, PWM, SPI MISO P0.29
16 TSOM_A4 / D4 A4 Analog in, GPIO D4, PWM, SPI MOSI P0.29
17 GND Ground.  
18 3V3 3.3V out, 1000 mA maximum including nRF52 and other peripherals.  
19 RUN Pull low to disable LTC7103 regulator. Has 100K pull-up to VIN.  
20 PGOOD LTC7103 regulator open drain power good output. Pulled low when regulator is not in regulation.  
21 GND Ground.  
22 GND Ground.  
23 VIN Power input, 6 - 90 VDC  
24 VIN Power input, 6 - 90 VDC  
25 LI+ Connect to Li-Po battery. Can power the device or be recharged by VIN or VBUS.  
26 GND Ground.  
27 TSOM_USB_VBUS nRF52 USB power input. Can be used as a 5V power supply instead of VIN.  
28 GND Ground.  
29 TSOM_VIN Tracker SoM power input 5V-12V DC.  
30 GND Ground.  
31 5V 5V power output when powered by VIN or USB  
32 GND Ground.  
33 TSOM_A0_SDA / D0 Wire SDA P0.03
34 TSOM_A1_SCL / D1 Wire SCL P0.02
35 TSOM_A2_BUTTON / D2 External user button, A2 Analog in, GPIO D2, PWM P0.28
36 TSOM_A3_BATT_TEMP / D3 Battery temperature sensor, A3 Analog in, GPIO D3, PWM P0.30
37 GND Ground.  
38 CAN_N CAN Data- or CANL  
39 CAN_P CAN Data+ or CANH  
40 CAN_5V 5V power out, 0.8A maximum. Can be controlled by software.  
41 GND Ground.  
42 TSOM_USB_N nRF52 MCU USB interface D-.  
43 TSOM_USB_P nRF52 MCU USB interface D+.  
44 GND Ground.  
45 RX / D9 Serial1 RX, GPIO D9, PWM, Wire3 SDA P0.08
46 TX / D8 Serial1 TX, GPIO D8, PWM, Wire3 SCL P0.06
47 RTC_BAT RTC/Watchdog battery +. Connect to GND if not using.  
48 RTC_EXTI RTC EXTI. Can use as a wake button. Has 100K weak pull-up to 3V3.  
  • Pins 9 and 10 have NFC in the name from the Tracker SoM, however NFC cannot be used on the Monitor One as the pins must be used as VIN_EN and PERIPH_INT.

I/O characteristics

The GPIO pins on the expansion connector have the following specifications, from the nRF52840 datasheet:

Symbol Parameter Min Typ Max Unit
VIH Input high voltage 0.7 xVDD VDD V
VIL Input low voltage VSS 0.3 xVDD V
VOH,SD Output high voltage, standard drive, 0.5 mA, VDD ≥1.7 VDD - 0.4 VDD V
VOH,HDH Output high voltage, high drive, 5 mA, VDD >= 2.7 V VDD - 0.4 VDD V
VOH,HDL Output high voltage, high drive, 3 mA, VDD >= 1.7 V VDD - 0.4 VDD V
VOL,SD Output low voltage, standard drive, 0.5 mA, VDD ≥1.7 VSS VSS + 0.4 V
VOL,HDH Output low voltage, high drive, 5 mA, VDD >= 2.7 V VSS VSS + 0.4 V
VOL,HDL Output low voltage, high drive,3 mA, VDD >= 1.7 V VSS VSS + 0.4 V
IOL,SD Current at VSS+0.4 V, output set low, standard drive, VDD≥1.7 1 2 4 mA
IOL,HDH Current at VSS+0.4 V, output set low, high drive, VDD >= 2.7V 6 10 15 mA
IOL,HDL Current at VSS+0.4 V, output set low, high drive, VDD >= 1.7V 3 mA
IOH,SD Current at VDD-0.4 V, output set high, standard drive, VDD≥1.7 1 2 4 mA
IOH,HDH Current at VDD-0.4 V, output set high, high drive, VDD >= 2.7V 6 9 14 mA
IOH,HDL Current at VDD-0.4 V, output set high, high drive, VDD >= 1.7V 3 mA
RPU Pull-up resistance 11 13 16
RPD Pull-down resistance 11 13 16
  • GPIO default to standard drive (2mA) but can be reconfigured to high drive (9mA) in Device OS 2.0.0 and later using the pinSetDriveStrength() function.

GPIO and port leakage current warning

Be careful when you are connecting GPIO or ports such as serial that may have power when the Monitor One is not powered, such as when using shipping mode.

If you have current flowing into GPIO or ports of the nRF52840 when it is powered down, it can cause it to enter a state where it cannot be reawaked without removing all power from it, including the internal LiPo battery. This may be difficult if you've sealed your Monitor One enclosure.

The Tracker One has a TI TS3A5018 Quad SPDT Analog Switch on the three GPIO pins (A3, D9/RX/SDA, D8/TX/SCL) to prevent this. The switch is normally open, and is closed when the CAN_5V is powered. By default, Tracker Edge enables CAN_5V when in normal operating mode and turns it off during sleep, however this behavior can be changed by using enableIoCanPower() and enableIoCanPowerSleep() in the TrackerConfiguration object.

The Tracker One circuit looks like this, and you may want to implement something similar if you are in a scenario where you have externally powered peripherals.

CAN Protection Circuitry

This is not necessary if your external peripherals are powered by 3V3 or CAN_5V.

VIN disable

By default, if power is applied at the VIN pin it will be used to power the Monitor One and charge the built-in battery.

If you are supplying VIN from another, larger battery pack, and want to be able to disconnect the VIN power supply to minimize current loss, you can do so using the following circuit:

VIN disable

By disconnecting the VIN power supply, it reduces the current used by the VIN and PMIC voltage regulators. The Monitor One can still be powered by its internal LiPo battery. This is particularly advantageous if the Monitor One is in sleep mode while VIN is disconnected as the power supply loss will be large compared to the very low sleep current in this scenario.

GPIO and Ports vs. Tracker One

Pin Monitor One Tracker One
A0 I2C SDA1 Internal Thermistor
A1 I2C SCL1 User Button (not accessible)
A2 External Button GNSS lock indicator
A3 Battery Temperature M8 Analog in, GPIO
A4 Analog in, GPIO, PWM, SPI MOSI1 Not available
A5 Analog in, GPIO, PWM, SPI MISO1 Not available
A6 Analog in, GPIO, PWM, SPI SCK1 Not available
A7 Analog in, GPIO, PWM, SPI SS, WKP Not available
TX MCU serial TX, GPIO D8, Wire3 SCL1 MCU serial TX, GPIO D8, Wire3 SCL
RX MCU serial RX, GPIO D9, Wire3 SDA1 MCU serial RX, GPIO D9, Wire3 SDA

1Available on expansion card connector (internal)

  • On the Monitor One, the expansion card connector allows the use the I2C, Serial, and SPI at the same time
  • On the Tracker One, you must choose between using the M8 for either serial or I2C. SPI is not available.

Tracker feature comparison

Tracker SoM Tracker M Tracker One Monitor One
Style SMD Module Module All-in-one All-in-one
Enclosure Your design Your design Included Included
MCU nRF52840 RTL8721DM nRF52840 nRF52840
CPU Speed 60 MHz 200 MHz 64 MHz 64 MHz
Maximum user binary 256 KB 2 MB 256 KB 256 KB
Flash file system6 4 MB 2 MB 4 MB 4 MB
Base board Your design Included Included Included
Expansion connector Your design 8-pin M8 8-pin Multiple options
GNSS Antenna Your design Int/Ext2 Internal Int/Ext2
Cellular Antenna Your design Int/Ext2 Internal Int/Ext2
Wi-Fi geolocation antenna Your design Int/Ext5 Internal Internal
BLE Antenna Your design Int/Ext5 Internal Internal4
NFC Tag Your design n/a Included n/a
USB Connector Your design Micro B USB C Micro B (Int)3
System RGB LED Your design Included Included Included
External user button n/a n/a
User RGB LEDs 2
SETUP and MODE buttons Your design On board Inside Enclosure Inside Enclosure
External power 3.9 - 17 VDC 6 - 90 VDC 6 - 30 VDC 6 - 90 VDC
SPI Expansion card n/a Expansion card
I2C Expansion card M8 Expansion card
Serial Expansion card M8 Expansion card
Internal temperature sensor Your design
Battery temperature sensor n/a n/a
Controlling charging by temperature Your design In hardware In software In software

1On the Tracker One, the M8 can be configured for GPIO, I2C (SDA and SCL), or Serial (RX and TX) on two pins.

2Both internal and external GNSS and cellular are supported by physically changing the antenna connector inside the enclosure.

3There is no external MCU USB connector on the Monitor One.

4The Monitor One uses the Tracker SoM BLE chip antenna on the board and does not include a separate BLE antenna, but one could be added using the BLE U.FL connector.

5The Tracker M uses a shared antenna for BLE and Wi-Fi geolocation. You can use the built-in trace antenna or an external 2.4 GHz/5 GHz dual-band antenna, selectable in software.

6A small portion of the flash file system is used by the system, and a configurable portion can be used for store and forward, to optionally allow location publishes to be saved when the device is offline to be uploaded later. The remainder of the flash file system can be used by user applications.

Mechanical specifications

Operating temperature

To be provided at a later date.

Dimensions and weight

Dimensions Metric SAE
Width 121 mm 4 3/4"
Height 220 mm 8 5/8"
Depth 69 mm 2 11/16"
Weight 775 g 27.3 oz
Dimensions
Dimensions

Power consumption

To be provided at a later date.

Country compatibility

To be provided at a later date.


Ordering information

To be provided at a later date.


Certification

To be provided at a later date.

Product handling

ESD precautions

The Monitor One contains highly sensitive electronic circuitry and is an Electrostatic Sensitive Device (ESD). Handling an module without proper ESD protection may destroy or damage it permanently. Proper ESD handling and packaging procedures must be applied throughout the processing, handling and operation of any application that incorporates the module. ESD precautions should be implemented on the application board where the B series is mounted. Failure to observe these precautions can result in severe damage to the module!

Battery warning

CAUTION

RISK OF EXPLOSION IF BATTERY IS REPLACED BY AN INCORRECT TYPE. DISPOSE OF USED BATTERIES ACCORDING TO THE INSTRUCTIONS.

Disposal

WEEE

This device must be treated as Waste Electrical & Electronic Equipment (WEEE) when disposed of.

Any WEEE marked waste products must not be mixed with general household waste, but kept separate for the treatment, recovery and recycling of the materials used. For proper treatment, recovery and recycling; please take all WEEE marked waste to your Local Authority Civic waste site, where it will be accepted free of charge. If all consumers dispose of Waste Electrical & Electronic Equipment correctly, they will be helping to save valuable resources and preventing any potential negative effects upon human health and the environment of any hazardous materials that the waste may contain.

Revision history

Date Author Comments
2022-10-24 RK For internal review only
2023-02-14 RK Updated diagrams