# OpenTherm - TTL adapter

This adapter is designed to connect an OpenTherm compatible boiler to any TTL port (TTL-USB, ESP8266, ESP32, Arduino, etc).

- **Seller:** [Mind House](https://www.lectronz.com/stores/mind-in-ua), Berlin, Germany
- **Price:** €15.99 (EUR, before shipping and taxes)
- **Availability:** Sold out
- **Product page:** https://www.lectronz.com/products/opentherm-ttl-adapter

## Options

**TTL connector**

- JST XH 4 Pin 2.54mm with cable [Add €0.99]
- without (0 left)

## Links

- [Documentation](https://xyzroe.cc/OpenTherm-TTL-adapter/)
- [Code](https://github.com/xyzroe/OpenTherm-TTL-adapter)
- [Design Files](https://github.com/xyzroe/OpenTherm-TTL-adapter)

## Images

![OpenTherm - TTL adapter](https://lectronz-images.b-cdn.net/lectronz/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6NDM2MjEsInB1ciI6ImJsb2JfaWQifX0=--6d04350fe55adc63f22df62050d7a63a25827603/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJqcGciLCJyZXNpemVfdG9fbGltaXQiOls5NjAsNjQwXSwic2F2ZXIiOnsic3RyaXAiOnRydWV9fSwicHVyIjoidmFyaWF0aW9uIn19--970c165836a83091725a1a0fd4f37ce9408da1bf/ot_1.jpg)
![OpenTherm - TTL adapter](https://lectronz-images.b-cdn.net/lectronz/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6NDM2MjUsInB1ciI6ImJsb2JfaWQifX0=--b3e5e2e2fea028c4aae538cc7a97c7e70f2f9216/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJqcGciLCJyZXNpemVfdG9fbGltaXQiOls5NjAsNjQwXSwic2F2ZXIiOnsic3RyaXAiOnRydWV9fSwicHVyIjoidmFyaWF0aW9uIn19--970c165836a83091725a1a0fd4f37ce9408da1bf/ot_2.jpg)

## Description

Same size as popular RS485-TTL module for more compatibility.

As software part you can use:

[OpenTherm gateway for HomeAssistant](https://github.com/Laxilef/OTGateway) - very intelligent OT control firmware 🧠

[Tasmota OpenTherm](https://tasmota.github.io/docs/OpenTherm/) - perhaps the easiest way to connect the boiler to your smart home system 🏚

[Opentherm IO library for Arduino](https://github.com/jpraus/arduino-opentherm) or [OpenTherm Arduino/ESP8266 Library](https://github.com/ihormelnyk/opentherm_library/) (slave mode only)
if you want to build your own firmware 🛠

## Shipping policy

Some items ship from Germany and others from China. Please check.