A complete bike monitoring system including the following modules:
- Speed
- Cadence
- Heart Rate
- Power
- Distance to following vehicle - Ultra sonic ranger (USR)
- Temparature
- Gradient
Each module will be run using an nRF51 chip, interfacing with a hub (nRF52), which will communicate with an andriod smartphone using BLE.
This repo contains all code for the sensors and hub, our app is available on bitbucket: https://bitbucket.org/lukacstomi91/smartbike/commits/branch/master
This project is being undertaken as part of my Electronics and Electrical Engineering MEng degree at the University of Glasgow, along with 3 others.
All modules connect to each other via BLE, with the network looking like this:
Phone <-BLE-> Hub
Hub <-I2C-> Temparature, Gradient
Hub <-ADC-> Heart Rate
Hub <-BLE-> Speed
Hub <-BLE-> USR
Hub <-BLE-> Cadence <-BLE-> Force
Each module has further details in a readme file in each sub-folder
To simplify the BLE communication, and reduce on-air packages, the following BLE characteristics are used to communicate between the Hub and Phone.
| Data | Data range (all int) | size | Packaged in |
|---|---|---|---|
| Speed | 0-500 (wheel rpm) | uint16 | cscs measurement, last wheel event time |
| Total dist | 0-65000 (m) | uint32 | cscs measurement, cumulative wheel revs |
| Speed Bat | 0-100 | uint16* | (cscs measurement, last crank event time) upper byte |
| Cadence | 0-200 | uint16 | cscs measurement, cumulative crank revs |
| Cadence bat | 0-100 | uint16* | (cscs measurement, last crank event time) lower byte |
| Power | 0-1000 | uint16 | rcrs measurement, inst speed |
| Power bat | 0-100 | uint8 | rcrs measurement, inst cadence |
| USR | 0-250 (meters*10) | uint16 | rcrs measurement, inst stride length |
| USR bat | 0-100 | uint32 | rcrs measurement, total distance |
| Hub Bat | 0-100 | uint32* | (rcrs measurement, total distance) second byte |
| Gradient | 0-100 (degrees +50) | uint16* | (hrs measurment, RR-interval) upper byte |
| Temp | 0-120 (degrees +50) | uint16* | (hrs measurment, RR-interval) lower byte |
| Heart Rate | 0-250 | uint8 | hrs measurment, heart rate measurement value |
| Device info | - | - | Device Information Service |