Kettler Bridge

This software is a bridge between an old KettlerBike with USB Serial port to a fresh Bluetooth Low Energy peripheral implementing FTMS and some GATT services.

the bike appears as a controlable Bike (FTMS, with SIM and ERG support)
there is also a Cadence sensor, power meter and other services
In SIM mode : It implements a Power Curve to fit to external feeling.

it's a work in progress:

Working on the power curve
Implementing Gear Shift
Using Momentary buttons to shift gear up and down
Oled screen feedback

I was able to test it on a Kettler Ergorace (https://www.bikeradar.com/reviews/training/indoor-trainers/resistance-trainer/kettler-ergorace-trainer-review/) and ZWIFT.

setup

Install on a rasperypi zero with nodejs (version 8, some lib are not compiling on Node 10).

Power

We need to enable 1.2A USB power draw mode, otherwise the RPi limits the draw to 0.6A:

/boot/config.txt
---
# Force 1.2A USB draw
max_usb_current=1

NodeJS

nodejs : follow the link below and find a list of scripts. Just run the wget of the selected version, and ... you have a node with the coreect version. https://github.com/sdesalas/node-pi-zero version 8.10 is OK

BLeno special setup

We use the great bleno (from abandonware for continuous support) library for simulating a Bluetooth Peripheral followin the gatt FTMS protocol. see https://github.com/noble/bleno

Stop the bluetooth service (Bleno implements another stack)

sudo systemctl disable bluetooth
sudo hciconfig hci0 up

install lib

sudo apt-get install bluetooth bluez libbluetooth-dev libudev-dev

KettlerUSB2BLE

download the sources

git clone https://github.com/360manu/kettlerUSB2BLE.git
cd kettlerUSB2BLE

Install !! No Sudo for node install. It breaks the compilation

npm install

it can take a while as bleno must be compiled from sources.

Bike Setup

just plug an USB cable from your PI (data USB, the central one) to the USB I personnaly use 2 cables

One Mini USB to USB B
an old one from USB B to USB A it's not very clean but it works

The Linux version installed on the PI already contains the CP21xx drivers. -> Nothing special on this side

Usage

Start

First try (need to sudo for bleno):

sudo node server.js

You should hear a sound from the bike when the Serial connection is OK. On the bike screen, you can now see the "USB" icons

If you scan for BLE peripheral (use Nordic RF app fro ANdroid or IPhone for example) Your kettler bike should appear as KettlerBLE device with two services (power & FTMS)

website

The Bridge is also a simple web server. It help debuging and have more feedback on the current state of the bike.

I use a static IP for the PI (see the doc of your router)

modify the index.ejs (line 47) file with the ip of your raspbery
start your browser pi-adress:3000

you can follow the bridge activity on a simple website. It will display the current power, HR et speed and some logs. It's also possible to switch gears.

Running as a service

For an automatic launch with the raspberry

sudo systemctl link /home/pi/kettlerUSB2BLE/kettler.service

-> Created symlink /etc/systemd/system/kettler.service → /home/pi/kettlerUSB2BLE/kettler.service.

sudo systemctl enable kettler.service
sudo systemctl start kettler.service

future

Power Curve description with config
Oled feedback
Gear Shift

danheron/kettlerUSB2BLE