This page contains detailed instructions on building a module and flashing it with the latest firmware. Following these instructions will allow you to communicate with compatible inverters.
| ⚠️ | TSUN | [TSOL-M350](https://www.tsun-ess.com/Micro-Inverter/M350-M400), [TSOL-M400](https://www.tsun-ess.com/Micro-Inverter/M350-M400), [TSOL-M800/TSOL-M800(DE)](https://www.tsun-ess.com/Micro-Inverter/M800) | others may work as well (need to be verified). |
To build your own AhoyDTU, you only need a few things. Remember that the maker community is always developing new and innovative options that we may not have covered in this readme.
Start with an ESP8266 or ESP32, and combine it with an NRF24L01+ breakout board. Other ESP boards with at least 4MBytes of ROM may also be suitable.
Make sure to choose an NRF24L01+ module that includes the '+' in its name. This is important because we need the 250kbps features that are only available in the plus-variant.
**Attention**: The NRF24L01+ can only communicate with the MI/HM/TSUN inverter. For the HMS/HMT it is needed to use a CMT2300A!
To future-proof your setup and use our sister project OpenDTU, we recommend investing in an ESP32 board with two CPU cores. Additionally, you can use a NRF24L01+ module with an external antenna as a radio for superior performance and compatibility with upcoming developments.
If you are using the NRF24 directly on the ESP board, make sure to set the transmission power to the lowest possible level (this can be adjusted later in the web interface). Using a high transmission power can potentially cause problems.
The ESP board's built-in controller has limited reserves in case both WiFi and nRF are transmitting simultaneously.
If you are using additional interfaces, such as a display, the reserves will be further reduced.
If you are upgrading an existing installation, you may notice that the pins are set to '0' in the web GUI, which will prevent communication with the NRF module.
To resolve this, set MISO=19, MOSI=23, SCLK=18 in the settings.
This is the correct default for most ESP32 boards. For ESP82xx, simply saving the settings without changes should suffice.
1. install [esptool.py](https://docs.espressif.com/projects/esptool/en/latest/esp32/) if you haven't already.
2. download and extract the latest release bin-file from [ahoy_](https://github.com/grindylow/ahoy/releases)
3.`cd ahoy_v<XXX> && cp *esp32.bin esp32.bin`
4. Perhaps you need to replace `/dev/ttyUSB0` to match your acual device in the following command. Execute it afterwards: `esptool.py --port /dev/ttyUSB0 --chip esp32 --before default_reset --after hard_reset write_flash --flash_mode dout --flash_freq 40m --flash_size detect 0x1000 bootloader.bin 0x8000 partitions.bin 0x10000 esp32.bin`
5. Unplug and replug your device.
6. Open a serial monitor (e.g. Putty) @ 115200 Baud. You should see some messages regarding wifi.
After you have successfully flashed and powered up your Ahoy DTU, you can access it from your browser.<br/>
If your Ahoy DTU was able to log on to the configured WiFi network, it will try to obtain an IP address from your local DHCP server (in most cases this is your router).
If it cannot connect to your configured network, it will provide its own WiFi network that you can
to for further configuration.
The WiFi SSID *(the WiFi name)* and password are pre-configured and are set to SSID "`AHOY-DTU`" and password "`esp_8266`" by default.
The Ahoy DTU will keep this network open for a certain amount of time (default is 60sec).
If nothing connects to it and the time expires, it will retry to connect to the configured network, and so on.
If you are connected to your local network, just find out the IP address used or try the default name [http://ahoy-dtu/](http://ahoy-dtu/).
In most cases, your router will give you a hint.
If you connect to the WiFi the Ahoy DTU opens in case it could not connect to any other Network, the IP-Address of your Ahoy DTU is [http://192.168.4.1/](http://192.168.4.1/).
To take control of your Ahoy DTU, you can directly call one of the following sub-pages (e.g. [http://ahoy-dtu/setup](http://ahoy-dtu/setup) or [http://192.168.4.1/setup](http://192.168.4.1/setup) ).
