# Hardware options

There are currently two possible hardware options for this project, both in need of external power supply. A self powered board is under development by a member of the community and is currently being tested. 

## Hardware v1 by [@roarfred](https://github.com/roarfred)
Composed from a ESP12E (or F) chip, this ESP8266 based board is designed specifically for this project with an on board M-bus chip.

Building this project will require some skills in ordering and assembling electronic circuits as well as programming. No detailed instructions are available.

![The HAN Reader Hardware](v1/img/HanReaderInEnclosure.PNG)

*The completed board mounted in a [3D printed enclosure](/Enclosure)*

## Assembly of readily available modules
You can also use a ESP based development board and combine this with a M-Bus module. Here are a few boards that have been tested, each one has a dedicated firmware file in the releases section. 

### ESP8266 based boards

[Wemos D1 mini](https://docs.wemos.cc/en/latest/d1/d1_mini.html)
- M-Bus connected to GPIO5 (D1)
- Jump GPIO4 (D2) to GND to force AP mode during boot
- Dallas temp sensor connected to GPIO14 (D5)

### ESP32 based boards

[Wemos D32](https://docs.wemos.cc/en/latest/d32/d32.html) 
- M-Bus connected to GPIO16
- Jump GPIO4 to GND to force AP mode during boot
- Dallas temp sensor connected to GPIO14

[Adafruit HUZZAH32](https://www.adafruit.com/product/3405) 
- M-Bus connected to GPIO16


Combine one of above board with an M-Bus module. Connect 3.3v and GND together between the boards and connect the TX pin from the M-Bus board to the dedicated M-Bus pin on the ESP board.

[TSS721 M-BUS module board](https://www.aliexpress.com/item/TSS721/32751482255.html)

![FeatherMbus](img/feather_3010-00_mbus_slave.jpg)