Tasmota Serial (MQTT) Bridge for MQTT-CUL
==========================================



## Hardware

- Wemos D1 mini or equivalent ESP8266 board running Tasmota (tested with v9.3.1)
- DIY-CUL device (Arduino Pro Mini with aCULfw + C1101 Transceiver)
  - RX/TX connected to Wemos D1 mini hardware UART (TX->RX and vice versa) using level shifters



## Tasmota-Configuration

##### Set baudrate for Hardware-UART

CUL-Device uses 38400 bps

```
baudrate 38400
```



##### Set serial delimiter

```
serialdelimiter 128
```

- CUL finishes every message with CR+LF (*\r\n*)
- *serialdelimiter 128* filters all unprintable chars and seems to take both CR and LF as a delimiter - at least both are filtered out and consequent messages are not concatenated, which happens if using NO serialdelimiter (value set to >128)



##### Set serial config

```
SerialConfig 8N1
```



##### Initialize CUL on Tasmota startup

Additionally, Tasmota´s Serial bridge is only active after the *SerialSend* function was used once after startup.

In my setup I need to get also "RAW" data from CUL, as I am using remote controls not directly supported by the aCULfw firmware, so I use the X05 command. If this is not needed, the right command is likely to be X21. 
For details see: http://culfw.de/commandref.html 

```
rule1 on system#boot do serialsend X05\r\n endon
```

activate the rule:

```
rule1 1
```



##### Additional rule for publishing SerialReceived output on another topic

```
rule2 on SerialReceived#Data do publish MQTTCUL/received %value% endon
```

- Unfortunately this rule will only work if ther is NO control char in the received string, so it is mandatory to use a *SerialDelimiter* setting that filters out all of them (i.E. SerialDelimiter 128 does the job). 
- The output of this rule is ALWAYS UPPERCASE. Don´t know why, but that´s how Tasmota handles it. Regarding CUL output this could be a problem, as it outputs lowercase chars in most messages. 
  - **CUL2MQTT.py** handles this by putting all data received from MQTT-CUL topic to lowercase (as all of the logic has already been completed and was written based on the normal lowercase output seen on any CUL device). 
  - **CUL2MQTT.py** now also supports the Tasmota ***tele/TOPIC/RESULT*** output in JSON format directly. It is preferred to use it this way, without the additional rule.