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In this video, Kamilla is unboxing AVR-IoT Cellular Mini, a development kit that has been designed by Microchip technology around their AVR microcontroller along with added security and cellular connectivity features that make it ideal for quick and easy prototyping of IoT applications. The cellular connectivity is enabled with the on-board modem and a free sim card from Truphone with coverage across many countries. You can start programming the board straight out of the box within the Arduino code-supported environment, such as Arduino IDE, as the AVR-IoT Cellular Mini comes with the dedicated library that allows communication with the systems and components on the board.
Within the kit, you can expect to find
- The AVR-Cellular Mini board
- Flexible antenna from Molex
- 150MB, 90-Day SIM card from Truphone
AVR-IOT Cellular Mini – Block diagram
The processing is carried out by the microcontroller from AVR DB family, AVR128DB48, running at up to 24Mhz and with 128 KB Flash in 48-pin package.
One of the highlights of AVR DB family is the addition of multi-voltage I/O feature which is essentially an integrated level shifter that can be configured to voltages between 1.8 and 5.5V. Sometimes, your microcontroller might operate in a 5V logic level, but the sensor you are trying to connect operates in 3.3V. In this kind of scenario, you will need a logic level shifter to match up the voltage levels, otherwise, you might damage your components. With AVR DB microcontrollers, you do not need to use an external level shifter, thus reducing your BOM and using less space on the PCB.
MVIO vs External Logic Level Shifter – microchip.com
The MCU also features a set of opamps with an integrated feedback resistor network that allows for many useful configurations with no external components.
Secure element – ATECC608B
The board features a high-security cryptographic device from Microchip’s CryptoAuthenticationTM family, the ATECC608B co-processor with secure hardware-based key storage feature for storing up to 16 keys, certificates, data as well as security configurations.
The ATECC608B implements a complete asymmetric (public/private) key cryptographic signature solution based upon Elliptic Curve Cryptography and the ECDSA signature protocol.
The ATECC608B also implements AES-128, SHA256 and multiple SHA derivatives in hardware.
Access to the device can be made through an I2C Interface at speeds of up to 1 Mbps or Single Wire Interface (SWI) using a GPIO pin.
The ATECC608B is an upgrade to the previous ATECC608A device with enhanced security features, but still provides complete backwards compatibility.
Monarch 2 GM02S
The IoT Cellular Mini features Monarch 2 GM02S module from Sequans. It is based on a second-generation chip platform for LTE-M and/or NB-IoT LTE connectivity that provides improvements in performance and power consumption making it ideal for IoT applications. Monarch 2 GM02Smodule includes Sequans’ Single-SKU™ RF front end, an integrated EAL5+ secure enclave, enabling secure key storage and crypto applications and integrated SIM (iSIM).
The board also features temperature (MCP9808) and colour (VEML3328) sensors as well as an option to connect external sensors and actuators through a Qwiic / Stemma connector.
There is also an on-board debugger, various buttons and LEDs, and a battery charger.
Enabling cellular IoT
With the kit, you get an embedded SIM card from Truphone with 150MB available for the duration of 90 days since the activation date. Unlike traditional sim cards, embedded SIM or eSIM for short, allows switching network providers without removing the SIM as well as storing multiple profiles on a single device. In the context of IoT devices, where it is usually quite challenging to open and close the device’s enclosure, not having to physically change the sim is a big advantage of esims. Moreover, the device will not have to be tied to a specific location or network operator.
You can find more about Truphone, different types of eSIMs they offer as well as check the network coverage information for your region on their website. To start using the esim, you will first need to create an account with Truphone and activate your sim by providing ICCID and PUK codes, which could be found on the back of the plastic card.
Truphone offers a Connectivity Management platform for their customers with features like a dashboard for managing sim cards, getting an overview of connections usage, billing information and much more.
Link to kit's documentation page: AVR-IoT Cellular Mini | Microchip IoT Documentation