Custom nRF52840 GPS Bike Computer with ANT+, BLE, LCD

I am a third-year Electrical Engineering student at the University of Calgary and an avid cyclist and triathlete. I started this project because I wanted to understand how a complete commercial-style bike computer could be designed from the component level, while creating a platform that I could customize for my own cycling and triathlon training.

Rather than using a development board or combining several premade modules, I designed the complete multilayer PCB in Altium around a bare Nordic nRF52840 system-on-chip. This makes the project a challenging combination of embedded hardware, low-power design, RF communication, sensor integration, battery management, USB, and compact PCB layout.

The main features include:

• Nordic nRF52840 processor with Bluetooth Low Energy and ANT+ connectivity

• MAX-M10S GNSS receiver for speed, distance, position, and ride recording

• Low-power Sharp Memory LCD for outdoor readability

• Barometric pressure sensor for altitude and elevation tracking

• Low-power accelerometer for automatic wake and sleep functionality

• QSPI flash memory for storing ride and system data

• Physical buttons for reliable operation while riding

• USB-C charging, data communication, and firmware development

• SWD programming and debugging interface

• ESD protection on external connections

The power system is designed around a protected single-cell LiPo battery. A TI BQ24074 power-path charger allows the computer to operate from USB power while simultaneously charging the battery, with automatic selection between USB and battery power. A dedicated fuel gauge provides battery state information so that the remaining runtime can be displayed accurately.

The nRF52840 will communicate with cycling sensors through Bluetooth Low Energy and ANT+, including heart-rate monitors, cadence sensors, speed sensors, and power meters. The GNSS receiver provides outdoor positioning and speed, while the barometer improves altitude and elevation-gain measurements.

The first firmware will be written specifically for this hardware. Initial functions will include automatic wake, live speed, position, altitude, elevation gain and loss, battery monitoring, sensor connectivity, and ride-data recording.

The electrical design and PCB layout are now being prepared for the first prototype fabrication and hardware bring-up. The first revision will be tested for power integrity, USB operation, charging, GNSS reception, wireless communication, sensor operation, display control, and low-power sleep current.

PCBWay sponsorship would help make the first physical prototype possible. I intend to document the assembly, bring-up process, test results, problems discovered, design improvements, and real-world ride testing so that other students and electronics designers can learn from the complete development process.

Additional schematic diagrams, PCB renders, design details, and project updates are available on my engineering portfolio: https://bryce-ilcan-portfolio.r8v556dh6c.chatgpt.site/projects/nrf52840-bike-computer