Nordic Semi nRF91-series of Cortex-M33 SoCs with NB-IoT and LTE-M (eMTC) cellular IoT connectivity was first unveiled in 2018. The first member of the family is nRF9160 System-in-Package (SiP) which also comes with GPS, and we’ve found it Nordic’s own Thingy:91 devkit, as well as in various modules and development boards from third parties.
There’s now a new kit called Pebble Tracker that features Nordic Semi nRF9160 with NB-IoT, LTE-M, and GPS connectivity, as well as environmental, motion, and light sensors. The cellular IoT prototyping platform works with the IoTeX blockchain to design decentralized IoT solutions with higher security.
Pebble Tracker hardware specifications:
Wireless module – Nordic Semi nRF9610 SiP
MCU Core - Arm Cortex-M33 @ 64 MHz
Storage & Memory – 1 MB flash, 256 KB SRAM
Connectivity – LTE-M / NB-IoT modem with support for bands from 700 MHz to 2.2 GHz)
Security – Arm TrustZone
IoT SIM card slot
GNSS – TD1030 GPS receiver (time-multiplexed with LTE modem) with 3-meter position accuracy, 0.1 m/s speed accuracy, plus external antenna
Bosch BME680 Environmental Sensor for humidity, pressure, temperature, and air quality (VOCs) measurements
ICM-42605 Motion Sensor with 3-axis gyroscope, 3-axis accelerometer
AMS TSL2572 Ambient Light Sensor
Programming/Debugging – 1x Micro USB port for programming, J-Link data port
Misc – 2700 Hz buzzer, RGB LED, Power & Reset buttons
Supply Voltage – 3 V to 5.5 V via a power connector
Dimensions – 5.3 x 3.5 cm
Weight – ~10 g
It’s interesting to note that the board relies on an external GPS instead of the built-in GPS found in (some?) nRF9160 SiP. Maybe the need for a higher position and speed accuracy drove the move.
Pebble Tracker firmware is open-source with the code available on Github and can be used with ThingsBoard open-source IoT platform to manage the devices, process and visualize data for the sensors as pictured in the above screenshot, or other IoT solutions.
Pebble Tracker specifically offers either hosted or custom backend configurations:
The hosted backend utilizes open-source software including hmq (MQTT broker), minIO (K8S storage), and ThingsBoard (data visualization) that typically used for prototyping and development
The custom backend is used for production/deployment with, for instance, AWS IoT Core (device management), AWS S3 (object storage), and ThingsBoard (data visualization) with support for SSL/TLS client certificates.
Check out the documentation to get started with Pebble.
Since the board is made by IoTeX, and the company highlights its blockchain solution which is said to improve node to cloud security:
Pebble Tracker integrates seamlessly with the IoTeX blockchain to empower decentralized IoT solutions with end-to-end trust. The combination of blockchain and secure hardware is incredibly powerful, allowing verifiable data from trusted devices to enforce the execution of verifiable smart contracts on the blockchain. While tamper-proof hardware like Pebble Tracker offers trusted data, tamper-proof software like blockchain offers trusted execution of code. When combined, blockchain + IoT ensures both the provenance/authenticity of data and the verifiability of data processing without the need for centralized, error-prone intermediaries.
The higher trust enabled by blockchain technology is supposed to enable new IoT applications with smart contracts being used for payments, automated workflows, and SLAs.
IoTeX has just launched the Pebble Tracker on Crowd Supply, where you can pledge $99 for the board, a plastic enclosure, an LTE antenna, a Micro USB-to-USB-Type-A cable, and a label with the board’s IMEI number which makes it competitive with other nRF9160 boards as we can see from the table below. Shipping adds $8 to the US and a bit more to the rest of the world, and rewards are scheduled to start shipping in mid-June 2021.