schellenberg-usb

The aim is to control a Schellenberg belt winder with the Schellenberg RF-Stick. UI is only a REST interface, which can be easily integrated into any third party system (e.g.: Home Assistant). The application that communicates directly with the USB RF Stick was developed in C# .NET 8.0. The Nuget LibUsbDotNet was used for USB communication. This ensures that the solution can be run platform-independently. The solution was developed in a Windows environment and will ultimately run dockerized on a Raspberry PI (Linux).

The following HW components were used and tested for the development:

• Schellenberg Rollodrive 75 premium (DE 22576)
• Schellenberg radio stick (DE 21009)

The development was only possible thanks to the friendly support of @LoPablo and @Hypfer. Their research into the protocol is the base on which I was able to build this solution (see schellenberg-qivicon-usb).

Even though the basic functionalities are currently implemented, this project is still under development. I am grateful for any constructive feedback.

State Machine definition overview

stateDiagram-v2
	Unknown --> Starting : Init
	Starting --> Idle : Started
	Idle --> Moving : MoveUpReceived / Function
	Idle --> Moving : MoveDownReceived / Function
	Idle --> Moving : MoveUpPressed / Function
	Idle --> Moving : MoveDownPressed / Function
	Idle --> Pairing : PairingStartedReceived
	Moving --> Idle : StopReceived / Function
	Moving --> Moving : MoveDownPressed / Function
	Moving --> Moving : MoveDownReceived / Function
	Moving --> Moving : MoveUpPressed / Function
	Moving --> Moving : MoveUpReceived / Function
	Pairing --> Idle : Paired / Function
    [*] --> Unknown

Loading

API

REST call	Description
GET http://:5080/schellenberg/	Get status info, response is a json {   "version": "0.1.0",   "lastUpdate": "2025-01-31T15:21:26.363619+00:00",   "name": "Schellenberg Rollodrive Premium",   "message": "usbdev1.4",   "fsm_state": "Idle" }
POST http://:5080/schellenberg/pair	Pair the cover drive with the RF Usb stick, under construction (payload should be the unique device ID)
GET http://:5080/schellenberg/up	Drive the cover up, response is a updated json
GET http://:5080/schellenberg/stop	Stop the cover driving, response is a updated json
GET http://:5080/schellenberg/down	Drive the cover down, response is a updated json

Docker image for RaspberryPI

https://hub.docker.com/repository/docker/atilladocker/schellenberg-web2rf-api

Running the solution

Linux as runtime environment

The following Linux distribution is installed on the Raspberry Raspberry Pi 3 Model B Rev 1.2 with docker/docker compose:

PRETTY_NAME="Debian GNU/Linux 11 (bullseye)"
NAME="Debian GNU/Linux"
VERSION_ID="11"
VERSION="11 (bullseye)"
VERSION_CODENAME=bullseye
ID=debian
HOME_URL="https://www.debian.org/"
SUPPORT_URL="https://www.debian.org/support"
BUG_REPORT_URL="https://bugs.debian.org/"

USB driver challenge under linux

Check detailed USB info:

lsusb

or

sudo usb-devices | grep -A 5 "16c0"

In the response you can see the loaded driver. We had the CDC device with VID/PID 16c0:05e1 attached. For this type of device, the Linux kernel typically loads the 'cdc_acm' driver automatically, which is likely causing "Resource busy" error. If the cdc_acm driver is definitely attached to your device on your interfaces try a aggressive approach to prevent cdc_acm from claiming the device:

Create a blacklist file to prevent cdc_acm from loading at all. The blacklist method is an effective way to prevent the cdc_acm driver from interfering with your USB device. By adding blacklist cdc_acm to the modprobe configuration, you've ensured that the Linux kernel won't automatically load this driver, which was causing the "Resource busy" error in LibUsbDotNet.

This approach:

• Blacklists cdc_acm globally
• Adds a specific quirk for your device's VID:PID combination
• Prevents only this specific device from using the cdc_acm driver

Create/modify file:

sudo nano /etc/modprobe.d/blacklist-cdc-acm.conf

Add this line as file content:

blacklist cdc_acm
options cdc_acm quirks=0x16c0:0x05e1:0x004

Then reload modules:

sudo update-initramfs -u
sudo reboot

Docker

Copy docker-compose.yaml file to server using ssh:

scp -O .\docker-compose.yaml <user>@<hostip>:/home/schellenberg-service/

You can also create your own docker-compose.yaml file:

Content of the docker compose file

services:  
  schellenberg-api-service:
    image: atilladocker/schellenberg-web2rf-api:0.1.0
    container_name: schellenberg-api-service
    restart: always
    ports:
      - 5080:8080
    devices:
      - "/dev/bus/usb:/dev/bus/usb"    
    privileged: true
    

Start container

docker compose -f docker-compose.yaml up -d