Protocol decoder:easymatic
| File:Easymatic.jpg | |
| Name | EASYMATIC |
|---|---|
| Description | Asynchronous, serial bus, differential |
| Status | planned |
| License | GPLv2+ |
| Source code | decoders/uart |
| Input | logic |
| Output | Easymatic protocol |
| Probes | — |
| Optional probes | Thermostat, Boiler |
| Options | invert_thermostat, invert_boiler |
The easymatic protocol decoder can decode the thermostat Easymatic bus protocol used by De Dietrich.
Hardware
Differential link
The easymatic is linked to the boiler with two wires. This link can feed power to the easymatic. Easymatic can have two R4 accu in order to save data if the power cut. Boiler power is a 24V modulated with communication power.
Communication is always working.
[To be confirmed]
The hardware is similar to OpenTherm Specifications : - differential link - about 24V - tension modulation for boiler - intensity modulation for thermostat (easymatic) ?
In order to link with a logic analyzer Saleae Logic an interface must be done.
Electrical coding
[To be define]
Idle state
[To be define]
Protocol
Uart based
Whereas OpenTherm use Manchester code, the easymatic seems to be based on Universal Asynchronous Receiver Transmitter (UART). It's a : - 1200 bauds communication. - 8 bits of data - no parity - one stop bit
The bit order of the 8 data bits is LSB-first.
details
[To be discovered and detailed]
Frames are repeated twice
To be define : how an order is send
All frame are composed by 6 bytes Boiler frames begin with a byte in 01, 03, 05, 07, 09, 0B, 0D Thermostat frames begin with a "boiler beginning frame +1" : 02, 04, 06, 08, 0A, 0C, 0E
Frame 0A/0B
| Frame (first byte) | 2sd byte | 3th byte | 4th byte | 5th byte | 6th byte | Comments |
|---|---|---|---|---|---|---|
| 0A | ? | ? | ? | ? | ? | |
| 0B | ? | ? | ? | T°C exterior | example : 70,0°C = 0700DEC = 02BCHEX | |
| 0C | 00? | T°C max boiler | Set point frost protection T°C exterior | |||
| 0D | 00? | 00? | 00? | T°C exterior | ||
| 0E | Hour | Day | Minutes | FF? | FF? | |
| 01 | 40? | T°C drink water | T°C boiler water | |||
| 02 | C1? | Set point room T°C day | Set point room T°C night | |||
| 03 | 00? | ? | ? | ? | ? | |
| 04 | 05? | Set point frost protection room T°C | Set point T°C drink water | |||
| 05 | Boiler bits command | Set point frost protection room T°C | Set point T°C drink water | |||