esphome / esphome/feature-requests

Support for DS28E17 1-Wire secondary to I2C primary bridge

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#1,985 7 comments 11 reactions 0 assignees View on GitHub
Type: One Wire
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Description

**Describe the problem you have/What new integration you would like**
Since 1-Wire sensors work reliably over more than 100 meters (if wired up properly), it allows having a central esp32 hub running esphome, with cheap 1-Wire sensors all distributed over the entire place. It currently limits the use of the Dallas 1-Wire bus to common 1-Wire temperature sensors and so on.

Using much more advanced I2C components over a longer distance (eg. ESP32 in distribution board and I2C component in different room, 20 meters apart) is unreliable at best, but mostly impossible.
One reliable way to allow the usage of remote I2C components, is to bridge them via the DS28E17 1-Wire module. That module will provide an I2C bus or rather it will tunnel I2C commands in the 1-Wire protocol, while keeping the actual I2C wires short, to remain inside the I2C bus capacitance limits.
![Typical application circuit](https://user-images.githubusercontent.com/1778889/204493456-c462b749-1737-4206-8a84-334986aacca8.png)

**Please describe your use case for this integration and alternatives you've tried:**
Implementing the DS28E17 1-Wire to I2C bridge in esphome would allow connecting all the currently supported I2C devices much further away from the esphome main board than before. That way it could for example be possible to have an MCP23017 (GPIO expander via I2C) remotely in a wall wiring box, and connect up to 16 switches to it, all connected via 1-Wire over a long distance to the main board. Even multiple DS28E17 are possible, each providing their own unique I2C bus, addressable via their 64 bit ROM ID.

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