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We’re looking for a Firmware Developer to join our team. The device firmware & hardware are already functional — your role is to understand the system and enhance it, not build from scratch. Need to work with MCU & Board: Nordic nRF52840 (ARM Cortex-M4) on custom PCB with BLE 5.0 Sensors: Optical glucose sensor (9 LEDs, 525–1700 nm) with photodiodes Accelerometer – LIS2DH Temperature – MLX90614 GSR for skin contact/stress monitoring PPG for heart rate & blood volume monitoring Hardware Architecture: Power management – BQ25155 PMIC with ship mode External SPI flash – MRX25R for data logging LED driver – DAC121S with configurable currents Multi-channel ADC with adjustable photodiode gains On-board battery charging and dock detection circuit Firmware Features: BLE pairing & secure bonding (fixed passkey) State machine for Acquisition, Idle, Dock, Error Handler Low-power sleep optimisation & ship mode (~tens of nA) Timestamped flash storage with bulk BLE download Requirements: Strong C/C++ embedded firmware experience Nordic SDK or Zephyr RTOS knowledge BLE communication & security expertise Low-power MCU design understanding Ability to read schematics & work with sensor datasheets
Project ID: 39699640
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Active 9 mos ago
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21 freelancers are bidding on average ₹1,125 INR/hour for this job

Greetings, I have completed full-stack projects for clients in similar domains where electronics, IoT and firmware had to align seamlessly. Taking responsibility for all saves you the hassle of coordinating between separate engineers. Approach: Concept & requirements definition. Electronics design: schematic, PCB, component selection, manufacturing readiness. Firmware: drivers, protocols (I2C/SPI/UART/RS-485), low-power optimization, application logic. Prototyping and validation with documented bring-up. Final delivery: Gerbers, BOM, firmware source, and complete documentation. My profile has case studies of consumer IoT devices, data loggers, motor controllers, and industrial systems where this combined approach ensured faster delivery and fewer iterations. I encourage you to review those projects for context and feedback from clients. To move forward, could you confirm if the focus is on cost optimization, low-power design, or compliance with specific standards? With that clarity, I’ll share a detailed execution plan. Looking forward to collaborating with you on this. Regards, Abbas Jawadwala | SMB ElectroTech
₹1,000 INR in 40 days
6.0
6.0

I have more than 10 years experience in electronics hardware design and firmware development with full product prototype . and i have already done many products based on NRF5 . So I can do your job within a time limit with your satisfaction.
₹3,500 INR in 40 days
4.9
4.9

Working in the field of Electrical Engineering and Automation since 5 years sets me apart from lots of programmers. During this tenure, I have developed my expertise in C++, Python, C#, Java & HTML using Arduino, Raspberry Pi, ESP8266, Orange Pi, Atmega 328p and numerous other microcontrollers. I have made projects for various clients which include various Control Systems, Automation Systems and custom boards to achieve various specific applications.
₹1,000 INR in 40 days
3.8
3.8

Hello, I am an experienced firmware developer specializing in embedded systems with strong expertise in C/C++ and Nordic nRF52840 MCU, ready to enhance your already functional device firmware. Key Skills & Experience: Proficient in Nordic SDK and Zephyr RTOS for robust firmware development. Deep knowledge of BLE communication, secure bonding, and low-power design techniques. Experience with multi-sensor integration including optical glucose sensors, accelerometers (LIS2DH), temperature sensors (MLX90614), GSR, and PPG sensors. Skilled in power management optimization, including PMIC control and ultra-low power modes (ship mode at tens of nA). Ability to read and interpret schematics and sensor datasheets for effective system-level debugging and enhancement. Experienced in implementing state machines, timestamped flash storage, and bulk BLE data transfer. I will thoroughly understand your current system, optimize firmware performance, enhance features, and ensure reliable, secure operation. Best regards, Vicky Keswani
₹1,000 INR in 40 days
3.5
3.5

Hello there, As an Embedded Software Engineer with a strong experience in Embedded Software Development, Bare-metal, Device Drivers, RTOS/Zephyr, I can deliver your projects with all requirements. In addition. I am an Open Source Contributor in ZephyrRTOS and Linux
₹1,000 INR in 40 days
1.8
1.8

hi, I’m an embedded firmware engineer with strong C/C++ skills, specializing in ARM Cortex-M MCUs, BLE communication. Experienced in integrating of sensors, managing data logging to external flash, and implementing secure wireless communication. Proficient with hardware-level debugging, I focus on enhancing and optimizing existing firmware for performance, stability, and efficiency. thanks, ankur matariya
₹1,100 INR in 30 days
0.7
0.7

I have more than 8 years of experience working C, C++ and Linux/RTOS Embedded. Worked on both application and device drivers (i2c, spi, usb, ethernet, lcd etc). Worked on QT also (recent experience). Have done yocto customization, recipe preparation, build scripts etc. Keen to involve in this project, please discuss. Negotiable Price
₹1,000 INR in 40 days
0.0
0.0

With well-versed proficiency in high-level programming languages such as C++, I have the ability to deeply understand existing codes and systems - exactly what your project requires. Having worked extensively on embedded systems and sensors, developing firmware for your device on the Nordic nRF52840 is something I can tackle effortlessly. Having in-depth knowledge of the MCU and Board specifics, such as BLE 5.0 with security expertise is a part of my routine tasks. My keen eye for reading schematics and sensor datasheets will prove to be an asset here. I am experienced in incorporating power management techniques for longevity, sleep optimization and even implementing ship mode of (tens of nA) that proves to be essential for low-power MCUs like ours. The timestamped flash storage demands bulk data download via BLE; which I have successfully delivered in prior projects.
₹990 INR in 1 day
0.0
0.0

I am a Nanoelectronics & Embedded Systems Engineer with extensive experience in C/C++ firmware development, Nordic nRF52840 (ARM Cortex-M4), and low-power IoT devices. I have worked on BLE 5.0 communication, secure pairing/bonding, and state machine–based control for data acquisition systems. My skills include: - Nordic SDK & Zephyr RTOS development - Sensor integration (optical, temperature, accelerometer, PPG, GSR) with SPI/I²C - Low-power optimization for battery-powered devices (~nA sleep currents) - External SPI flash storage & timestamped data logging - Schematic reading and debugging hardware–firmware interaction I can quickly understand your current firmware and enhance it for improved performance, reliability, and efficiency.
₹750 INR in 40 days
0.0
0.0

I have experience with IOT applications and also worked on nrf52840 for ble. Have experience with flash memory peripherals and accelerometers. I just need on chance to prove it. If you need any proof of concept regarding your project I can do it for free. If you are okay with it then only we can start onyour project. I'm also working as a full time IOT developer in a product based start up. That's why I can give only 20hrs per week, but these 20hrs would be enough for me because I already have drivers related to these devices. I just need to integrate them.
₹750 INR in 20 days
0.0
0.0

I have previously worked with nRF MCUs and currently have free time to dedicate fully. I am committed and can work diligently while integrating smoothly into a team. Although I had no prior experience, I successfully completed a vehicle tracking project with my team. Now, I aim to consolidate and further develop the experience I have gained, and I hope to be part of your team in the long term. I am eager to apply and strengthen my skills in embedded firmware development, BLE communication and security, low-power MCU design, as well as reading schematics and working with sensor datasheets.
₹1,000 INR in 40 days
0.0
0.0

I am a firmware developer with 2.5 years of experience Worked on BLE and Bluetooth Classic in Android system pairing with multiple devices
₹750 INR in 40 days
0.0
0.0

As a skilled Embedded Software Engineer, I have worked with a wide range of microcontrollers, including STM32, ESP32, TI CC2640, nRF9160, and nRF52840, as well as microprocessors like the Raspberry Pi and STM32MP series. I possess strong proficiency in C, C++, and Python. My experience includes working with various peripherals such as I2C, SPI, UART, ADC, DAC, and TIMERS. I have hands-on experience with LVGL for custom GUI design and have worked extensively on monitoring a variety of sensors interfacing via RS485, RS232, and CAN protocols. Additionally, I have deployed AI models on embedded hardware and implemented IoT communication protocols such as HTTP/HTTPS and MQTT/MQTTS. I am confident that my skill set and experience can bring valuable insights and contributions to any project I undertake.
₹1,000 INR in 40 days
0.0
0.0

I bring 19+ years of embedded firmware experience with deep expertise in C/C++, Nordic nRF52 series, BLE 5.0, and low-power design. I have worked extensively on sensor integration (accelerometers, PPG, temperature, optical) and can quickly understand your existing system to enhance it with robust, optimized, and maintainable code. My skills include Nordic SDK & Zephyr RTOS, secure BLE communication, ADC/LED driver handling, SPI flash logging, and state machine implementation. I focus on low-power optimization, reliability, and clear documentation, ensuring smooth collaboration and long-term maintainability. I’d be happy to contribute to your project and deliver enhancements that are scalable, efficient, and production-ready.
₹1,000 INR in 40 days
0.0
0.0

Hi this is really same project I have done while ago na could finish even in within stiputated time so please give it to me
₹1,000 INR in 40 days
0.0
0.0

My past projects include ESP32-S3 BLE + LVGL UI system, low-power sensor interfaces, I2C/SPI communication, and data logging firmware. These align closely with your architecture and requirements.
₹780 INR in 40 days
0.0
0.0

I am NSQF Level 5 Certified Embedded Software Engineer. I have experience with C/C++ Programming, Embedded C, Embedded System, Microcontroller, Linux, Qt/Qml. Also, I have hands-on experience in various projects like Car Black Box, Address Book, Steganography, Arbitrary Precision Calculator, Mini shell and etc. So, I would like to contribute myself for tour project with my expertise and will try to give you the best work by my knowledge.
₹1,000 INR in 40 days
0.0
0.0

Surat, India
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