ajvdw / emsbusshield Goto Github PK

Hello World,

For anyone who would like to know if this EMS Bus Shield is working, I can confirm that it works flawlessly with the EMS-ESP firmware. I have connected it to an old Nefit TopLine boiler, with a Moduline 400 thermostat and all communication is working properly!

Big thanks to Arie Johan for providing this GitHub repository including the Gerber files to be able to manufacture the PCB

Here were the steps involved for me:

1. Create the PCB by uploading the zip file with the gerbers to a PCB manufacturer. I used JLCPCB, but I guess PcbWay also works. It didn't cost that much, for about 10 Euros, you can get 5 PCB's. Excellent

2. Order the parts, e.g by Reichelt. I don't think it's very critical, but most (if not all) parts are so common that you get it delivered in a couple of days. Do not forget to also order the 2x10 pin headers for the D1 mini

3. Solder it together. I just my beloved 25 year old WECP-20, with normal soldering skills. I soldered all the pins of the 2x10 bus header, but I don't think all of them are needed.

4. Order your D1 mini ESP32 from somewhere. This device at AliExpress worked for me. Solder the pin headers onto the device.

5. Flash the ESP-Home firmware. I used the esptool commandline on a Linux device, after downloading the bin files involved. the bin files for esphome can be found here, and flash the stable or development version

6. Configure ESP-Home EMS-ESP (it's one the site). Configure it to connect to your Wifi network, and DO NOT FORGET to put the custom pin configuration in the settings. It's also on the README.MD on this repository, but I naively hoped it would work out of the box. If the blue led keeps blinking once, that might be the reason!

7. Connect to wires to your Boiler (I connected to the thermostat header), and browse the EMS-ESP site that your ESP32 exposes.

Play around with it and enjoy!

Good luck!

Richard

I have question about max voltage for powering the board. I used my lab power supply and if I set-up voltage to 12V an ESP board is bricked after few second (I can’t connect to ESP-EMS via Wi-Fi). If I used voltage between 7-9V ESP board working. I measured voltage on 78L05 and there is still 5V, but if I used 12V 78L05 is too hot (+70°C). Is this a bug or a feature?

Hi!

Thank you for your project! I'm looking to build the shield, but I'm not sure about L1 and L2 inductance values. In the original schematics at https://emsesp.github.io/docs/EMS-Circuit/#a-breadboard-prototype they have 4.7uH inductances, and your schematic has 4.7 mH. Is this correct? Or the difference doesn't matter much?

Thank you!