Hardware Overview¶

Recommended Operating Conditions¶

¹ Limited by the ability of the battery to supply a transmit current of 110mA.

Architecture¶

The Semtech LoRa Edge™ Tracker Reference Design architecture has the following characteristics:

• LR1110 Wi-Fi and GNSS capabilities

• GNSS antenna diversity

  • Patch antenna

  • PCB antenna

• STM32WB55 with BLE port configuration and update

• 2400 mAh battery

• 52 x 85 x 27 mm IP66 housing

• LEDs

• 3-Axis & Hall Effect Sensors

• Maximum transmit output power = +22 dBm

• Typical sensitivity level:

  • LoRa:

    • -140 dBm at SF12 BW 125 kHz

    • -127 dBm at SF7 BW 125 kHz

  • GNSS: -134 dBm

Block Diagram¶

Figure 7: LoRa Edge Tracker Reference Design Block Diagram¶

• The LoRa Basics™ Modem-E is an ultra-low power platform that integrates the following components:

  • Long-range LoRa transceiver

  • Multi-constellation scanner

  • Passive Wi-Fi AP MAC address scanner targeting asset management applications

• The STM32WB55XX multi-protocol wireless and ultra-low power devices embed a powerful and ultra-low power radio, compliant with the Bluetooth^® Low Energy SIG specification v5.0 and with IEEE 802.15.4-2011. They contain a dedicated Arm^® Cortex^® -M0+ for performing all real-time low-layer operations.

The control signals from/to the MCU and the LoRa Basics Modem-E are:

• 1 x SPI, coming from the MCU to the LoRa Basics Modem-E SPI interface

• LoRa Basics Modem-E SPI interface Reset / Event / Busy line

• 1 x I2C, coming from the MCU to the accelerometer sensor I2C interface

• GPIO for the Hall Effect sensor and user button

• Control lines for SPDT:

  • Two from the MCU, for GNSS antenna diversity and Wi-Fi/BLE selection.

  • One from the LoRa Basics Modem-E, for LoRa RX/TX path selection.

Power Consumption¶

Power Consumption Profile¶

This chapter describes the typical power consumption profiles with standard parameter settings.

Scan with Default Parameters¶

The power consumption profile has the following parameters:

• GNSS Scan mode: Assisted

• GNSS Search mode: Default

• GNSS Antenna selection: Both

• Wi-Fi Channels: Chan_1 / Chan_6 / Chan_11

• Wi-Fi Nb retrials: 5

• Wi-Fi Max result: 6

• Wi-Fi Timeout: 90ms

Figure 8 shows the power consumption profile using the default accuracy parameters when the tracker is outdoors (For information on the scan strategy, see Tracker Application Capabilities.)

Figure 8: Power Consumption Profile Scan using the Default Parameters, outdoor case¶

The complete scan power consumption is about 3.45mA / 12.37 sec; therefore, 11.89μAh. If we split the power consumption by functionality, we get:

• GNSS Scan (x 2):

  • First scan (3.52mA / 7.16 sec), corresponding to 7μAh.

  • Second scan (3.29mA / 5.14 sec), corresponding to 4.7μAh.

  Note

  The power consumption varies depending on the number of GNSS satellites detected. If only one antenna is used, the consumption can be halved (depending on the environment).

• Sensor readings (accelerometer / Hall Effect / charge): 8.53mA / 0.041 sec, corresponding to 0.09μA.

Figure 9 shows the power consumption profile using the default accuracy parameters when the tracker is indoors (For information on the scan strategy, see Tracker Application Capabilities.)

Figure 9: Power Consumption Profile Scan using the Default Parameters, indoor case¶

The complete scan power consumption is about 3.59mA / 5.14 sec; therefore, 5.13μAh. If we split the power consumption by functionality, we get:

• GNSS Scan: (3.29mA / 4.88 sec), corresponding to 4.4μAh.

• Wi-Fi: 10.08mA / 0.206 sec, corresponding to 0.57μAh.

Note

The power consumption varies depending on the number of Wi-Fi access points or GNSS satellites detected.

• Sensor readings (accelerometer / Hall Effect / charge): 8.53mA / 0.041 sec, corresponding to 0.09μAh.

Sleep Current¶

Figure 10: Power Consumption Profile in Sleep Mode¶

The average sleep current is approximately:

• 10.85μAh (without super-capacitors)

• 18.85μAh (with super-capacitors)

Each peak represents the accelerometer output data rate, here 100ms.

Antenna Performance¶

The antenna radiation patterns have been measured in a free space condition. The measurement setup and device orientation is shown in Figure 11.

Figure 11: Radiation Diagram Measurement Setup¶

LoRa Antenna Radiation Pattern¶

The 3-D radiation pattern of the LoRa antenna of each tracker type (868MHz and 915MHz) has been measured at the antenna operating frequency, as shown in the following sections.

868MHz Antenna¶

The 3-D radiation pattern at 868MHz and the 2-D cuts in the various planes are shown in Figure 13, Figure 14, and Figure 15.

TRP = 11.83dBm
EIRP = 13.84dBm
Efficiency = 46%
Gain = -1.36dBi

Figure 12: 3-D Pattern for Total Gain @ 868MHz¶

Figure 13: 2-D Radiation Pattern Planar Cut XoZ Plane @868MHz¶

Figure 14: 2-D Radiation Pattern Planar Cut YoZ Plane @868MHz¶

Figure 15: 2-D Radiation Pattern Planar cut XoY Plane @868MHz¶

915MHz Antenna¶

The 3-D radiation pattern at 915MHz is shown in Figure 16, whereas the 2-D cuts in the various planes are shown in Figure 17, Figure 18, and Figure 19.

TRP = 17.24dBm
EIRP = 19.41dBm
Efficiency = 40%
Gain = -1.73dBi

Figure 16: 3-D Pattern for Total Gain 915MHz¶

Figure 17: 2-D Radiation Pattern Planar Cut XoZ Plane @915MHz¶

Figure 18: 2-D Radiation Pattern Planar Cut YoZ Plane @915MHz¶

Figure 19: 2-D Radiation Pattern Planar Cut XoY Plane @915MHz¶

GNSS Antenna Radiation Pattern¶

The 3-D radiation pattern of the GNSS PCB antenna at 1.575GHz is shown in Figure 20.

Figure 20: 3D Radiation Pattern of the GNSS PCB Antenna¶

2.4GHz Antenna Radiation Pattern¶

The 3-D radiation pattern of the 2.4GHz antenna at 2440MHz is shown in Figure 12, whereas the 2D cuts in the various planes are shown in Figures 21-24.

Figure 21: 3D Pattern for Total Gain @2440MHz¶

Figure 22: 2-D Radiation Pattern Planar Cut XoZ Plane @2440MHz¶

Figure 23: 2-D Radiation Pattern Planar Cut YoZ Plane @2440MHz¶

Figure 24: 2-D Radiation Pattern Planar Cut XoY Plane @2440MHz¶

QR Code Description¶

The QR code printed on the device label integrates the Device ID in the QR code, as defined by the LoRa Alliance^®.

Figure 25: EU Label¶

Figure 26: U.S. Label¶

The QR code contains the following information:

• Preface: LW

• SchemaID: D0

• JoinEUI: (00-16-C0-01-FF-FE-00-01 in this example)

• DevEUI: (00-16-C0-01-F0-00-14-9A in this example)

• ProfileID: 016A-0001

• OwnerToken: 4A21235D: pin of the LoRa Basics Modem-E

• SerNum of Mfg Serial Number: YYWWNNNNNN (Year, Week, Serial Number)

• Proprietary: US915 (for U.S.), EU868 (for EU)

• CheckSum: (CRC-16/MODBUS)

The information contained in the QR code represents 58 bytes of data:

LW:D0:0016C001FFFE0001:0016C001F000149A:016A0001:O4A21235D:S2126220290:PEU868

With the CRC, we have 64 bytes of data:

LW:D0:0016C001FFFE0001:0016C001F000149A:016A0001:O4A21235D:S2126220290:PEU868:C7ECF

For more information, see TR005 LoRaWAN® Device Identification QR Codes.