ESPHome-PHC-Controller

This project implements a PEHA(acquired by Honeywell) PHC Controller which integrates into Home Assistant through ESPHome. This solution can replace an existing dumb controller (STM - Steuermodul), thus smartifying an existing PEHA PHC installation.

Demo installation

Smart PHC controller with PHC-Modules. A close up of the board containing the ESP32 with the RS-485 converter and a step-down module can be found here.

Requirements

This project has been developed and tested on an ESP32. A ESP8266 is probably going to work just fine. For best results use an ESP32 in combination with the Arduino Framework. The use of the and ESP8266 or the IDF framework will likely result in incorrectly timed messages on the bus.

The PHC-Bus is RS-485 based. In order communicate on the bus a RS-485 TTL Adapter is required. Currently only a Chip with automatic flow control has been tested. Connect the A/B wires to the PHC-bus. This can easily be done using the screw-terminal on the power-supply (see). Finally connect the RS-485 adapter to your ESP and you are good to go.

With the help of a step-down module/voltage converter the 24V supplied by the PHC-power-supply can be used to power the ESP.

Make sure to remove any existing controllers (STM - Steuermodul) from the bus, as they will interfere.

Configuration variables

A example configuration can be found here

PHC Controller

id(Required, string): Controller ID which will be used for entity configuration.
uart_id(Required, string): ID of the UART-Component connected to the PHC-Bus

AMD(Output module/Ausgangsmodul) as switch

phc_controller_id(Required, string): The PHC-Controller to which this entity belongs
address(Required, int): Module DIP-Switch address
channel(Required, int): Output channel on the Module
All other options from Switch

AMD(Output module/Ausgangsmodul) as light

phc_controller_id(Required, string): The PHC-Controller to which this entity belongs
address(Required, int): Module DIP-Switch address
channel(Required, int): Output channel on the Module
All other options from Light

EMD(Input module/Eingangsmodul) Output as light

phc_controller_id(Required, string): The PHC-Controller to which this entity belongs
address(Required, int): Module DIP-Switch address
channel(Required, int): Output channel on the Module
All other options from Light

EMD as binary sensor

phc_controller_id(Required, string): The PHC-Controller to which this entity belongs
address(Required, int): Module DIP-Switch address
channel(Required, int): Output channel on the Module
All other options from Binary Sensor

JRM(Blinds-Module/ Jalousie-Rolladen Modul)

phc_controller_id(Required, string): The PHC-Controller to which this entity belongs
address(Required, int): Module DIP-Switch address
channel(Required, int): Output channel on the Module
max_open_time(Optional, Time): Determines for how long the Output will be enabled while opening. This value should guarantee the cover reaches it's open state. Defaults to 30s.
max_close_time(Optional, Time): Determines for how long the Output will be enabled while closing. This value should guarantee the cover reaches it's closed state. Defaults to 30s.
assume_position(Optional): Assume the covers position based on measured open/close times
- open_time(Required, Time): The time it takes to open the cover completely from it's closed state. Must be smaller than max_open_time.
- close_time(Required, Time): The time it takes to close the cover completely from it's opened state. Must be smaller than max_close_time.
All other options from Cover

Related work

Without previous reverse engineering work done by others this would have been a lot more time consuming.

Throubleshooting

The UART debug function can be used to analyze communication on the bus.
Kown Memory Issues:
- ESP8266 out-of-memory exception
- Guru Meditation Error: exception caused by LOOP_STACK_SIZE exceeded
  - solution

TillFleisch / ESPHome-PHC-Controller