OpenVSH is an open-source firmware for Vimar Smart Home devices. It uses the Zigbee standard for device control and Bluetooth Low Energy (BLE) for Firmware Over-The-Air (FOTA) updates and configurations. The firmware is written using Zephyr OS and the NRF Connect SDK.
I have a Vimar Smart Home system installed in my home, primarily chosen for its compatibility with the Zigbee standard. However, the functionality of the products is quite limited. For example, on the 2-way switch, it's impossible to customize the status LED, the rolling shutter is cumbersome to configure, and some features are entirely lost on the thermostat. I decided to purchase their gateway and switched all devices to Bluetooth mode, but this turned out to be slow and required internet access for commands sent from their app, even when I'm inside the house.
Frustrated with these issues, I opened one of the devices and discovered that it uses the Nordic Semiconductor nRF52840 SoC. I then purchased the development kit and rewrote the firmware for the 2-way switch. Fortunately, Vimar's boards conveniently expose the SWD pins needed to completely rewrite the chip's memory. After some testing, I was able to identify and use them to apply the new firmware. I have since decided to rewrite the firmware for all the devices I have, using Zigbee standard. Why Zigbee? I tested Matter over Thread, but it unfortunately requires more flash memory than what is available on the SoC, and the boards lack external flash memory.
| Vimar product name / code | OpenVSH device name | Status |
|---|---|---|
| 2-way switch IoT connected mechanism (14592, 16492, 19592, 20592, 30802) | On/Off Light | Beta |
| Rolling shutter IoT connected mechanism (14594, 16494, 19594, 20594, 30804) | Window Covering | Planned |
| IoT dial thermostat 2M (02973, 30810) | Thermostat | Planned |
| IoT connected dimmer mechanism 220-240V (14595, 19595, 20595, 30805) | Dimmable Light | Not Planned |
| 16 A IoT connected actuator (14593, 16493, 19593, 20593, 30803) | Not Planned |
Before flashing the device, you need to either build the firmware or download the hex file for your device from the latest release. To flash the firmware, you'll need an SWD-compatible debug probe. Covering all use cases would be impossible, but below you'll find a brief guide explaining how to use SEGGER J-Link Debug Probes and the one included on the nRF52840 DK.
In any case, this operation only needs to be done once, as future updates will be handled via Firmware Over-The-Air (FOTA) using Bluetooth Low Energy (BLE).
To connect the SEGGER J-Link to an SWD connector, follow the pinout mentioned in the official documentation.
Once the debug probe is connected, you need to download the SEGGER J-Link Software. You can then use the JLinkExe command line tool to flash the device.
Create a script file flash.jlink:
Reset
LoadFile /path/to/your/file.hex
Reset
Go
Quit
Execute JLinkExe to flash the device:
JLinkExe -Device <DeviceName> -If SWD -speed 4000 -AutoConnect 1 -NoGui 1 -CommandFile flash.jlink
To flash the device using the SEGGER J-Link included on the nRF52840 DK (documented here), you need to use the P20 connector (documented here). The pins to connect are the same as with any SWD-compatible debug probe: "SWDIO", "SWDCLK", and "RESET". You also need to use "VDD nRF" and any "GND" pin from the board (for example, the one on the P17 connector) to power the device. Additionally, you need to connect "SWDSEL" to another "VDD nRF" to signal to the board that an external device is connected. This ensures that any command issued using SEGGER J-Link tools will be directed to the device rather than the board. Below is a diagram showing how to connect them:
Once the debug probe is connected, follow the last part of the SEGGER J-Link Debug Probes section, replacing DeviceName with NRF52840_XXAA. Alternatively, if you have installed the nRF Command Line Tools, you can use nrfjprog:
nrfjprog --program /path/to/your/file.hex --chiperase --verify --reset
Docs coming soon.
Docs coming soon.