This project was started from [this](https://www.mikrocontroller.net/topic/525778) discussion (Mikrocontroller.net).
It was the goal to replace the original Hoymiles DTU (Telemetry Gateway) with their cloud access. With a lot of reverse engineering the Hoymiles protocol was decrypted and analyzed.
* Clone this repository (you really have to clone it, don't just download the ZIP file. During the build process the git hash gets embedded into the firmware. If you download the ZIP file a build error will occur)
* In Visual Studio Code, choose File --> Open Folder and select the previously downloaded source code. (You have to select the folder which contains the "platformio.ini" file)
* Adjust the COM port in the file "platformio.ini". It occurs twice:
* Select the arrow button in the status bar (PlatformIO: Upload) to compile and upload the firmware. During the compilation, all required libraries are downloaded automatically.
* Clone this repository (you really have to clone it, don't just download the ZIP file. During the build process the git hash gets embedded into the firmware. If you download the ZIP file a build error will occur)
* Adjust the COM port in the file "platformio.ini". It occurs twice:
* upload_port
* monitor_port
* build: `platformio run -e generic`
* upload to esp module: `platformio run -e generic -t upload`
* other options:
* clean the sources: `platformio run -e generic -t clean`
* erase flash: `platformio run -e generic -t erase`
* OpenDTU then simultaneously connects to your WiFi AP with this credentials. Navigate to Info --> Network and look into section "Network Interface (Station)" for the IP address received via DHCP.
* When OpenDTU is connected to a configured WiFI AP, the "OpenDTU-*" Access Point is closed after 3 minutes.