FIRMWAREEssential Knowledge

Development Platform

Programming in C/C++ for microcontrollers (ARM Cortex-M33 in the case of the nRF9151).

Use of the nRF Connect SDK (based on Zephyr RTOS) for the nRF9151, including:

• Devicetree configuration

• Kconfig configuration

• RTOS management: tasks, queues, semaphores, and power management (PSM, eDRX for LTE)

Protocols and Connectivity

Implementation of stacks such as:

• MQTT
• CoAP
• HTTPS over LTE-M / NB-IoT

Use of TLS / DTLS and certificates for secure communication (Secure Socket API of the nRF9151).

Bus communication protocols:

• SPI
• I2C
• UART
• PDM
• PWM

(all available in the nRF9151)

LoRa / LoRaWAN protocol for the LoRa1278-C1 module.

Power Management

Optimization of power consumption for IoT devices: implementation of PSM (Power Saving Mode), eDRX, and wake/sleep cycles.

The nRF9151 can reach as low as 2.7 µA in PSM, therefore the firmware must properly take advantage of this capability.

Debugging and Tools

Use of SWD + J-Link / nRF9160 DK for flashing and debugging.

Analysis with:

• ITM
• ETM
• DWT

(available in Cortex-M33)

Basic CI/CD, version control using Git.

Management of OTA (firmware update over-the-air) for deployments in the field.

Embedded Security

Use of Arm TrustZone and Arm CryptoCell-310 (present in the nRF9151) for:

• Secure boot
• Key storage
• Secure communications

Please indicate:

• What experience do you have in PCB board design using Nordic chips?

• If you have used the C programming language, in what type of project did you use it?

• What work have you done with Zephyr RTOS?

Finally, please confirm whether you have experience or at least a working knowledge of the topics described above.

Job Type: Part-time

Work Location: Remote