BLE firmware upgrade enabling FTMS-based indoor cycling support on electric bikes for apps like Zwift.

The shift to virtual fitness demands hardware that integrates smoothly with leading platforms like Zwift. Without indoor trainer functionality, existing BLE modules were incompatible with key training apps. The goal: upgrade an electric bike’s BLE firmware to support FTMS for indoor cycling.

‍

Context

Delphian Systems’ older BLE/ANT+ module (SRU-532) previously enabled indoor training on electric bikes. But with that chip obsolete, the new BLE module based on Silicon Graphics’ BGM210PB32JIA2R lacked indoor support, halting compatibility with key applications.

Solution Highlights

The engineering team integrated Fitness Machine Service (FTMS) support into the BGM210PB32JIA2R chip’s firmware. Using the existing  PCB, the indoor training function now allows real-time status transmission to apps like Zwift.

• Transmits FTMS-compliant performance data
• Supports seamless phone app pairing
• Fully compatible with companion mobile fitness apps

‍

Problem statement

Before Indoor Trainer BLE Integration, our electric bike’s BLE module lacked indoor trainer functionality after the Delphian SRU-532 chip became obsolete. Without FTMS support, the new module using BGM210PB32JIA2R could not communicate with training apps like Zwift, blocking a critical feature for users who train indoors. Our users needed seamless app compatibility and reliable fitness data transmission, which the existing firmware could not provide.

‍

Solution

To resolve this, we integrated FTMS (Fitness Machine Service) into the firmware running on the BGM210PB32JIA2R BLE module. This allowed the system to transmit real-time cycling data—speed, resistance, cadence, power—over BLE to apps like Zwift. Development used the provided BLE hardware PCB and existing schematics.
Compatibility testing ensured seamless operation with companion mobile fitness apps and third-party platforms. The module’s firmware was restructured to simulate indoor cycling conditions while maintaining stable BLE communication.
App compatibility was achieved with Zwift and other FTMS-supported platforms, ensuring the BLE module now supports both indoor and outdoor scenarios.

‍

Value add

The integration restored critical functionality for indoor cyclists using our e-bike platform, reducing the need for third-party sensors or expensive trainer upgrades. The firmware extension maximized reuse of existing hardware, ensuring long-term support and lower total cost of ownership. Its FTMS-based implementation allows scalable support for any future fitness apps using standard BLE protocols.

‍