@kimot No, it is an obvious mistake, I am very sorry. Maybe it is becouse the code in master branch is very old, the newest is not yet on github, but the developement branch is quite new. I am going to fix this soon.

@kimot in theory you might be right, but in practice... it just works. The propability of collisions is extremely low and this is, as far as I know, the only problem you can worry about. After all, it was not my idea to use MySensors with RS485: https://www.mysensors.org/build/rs485

This is great, thanks! One suggestion: add a switch mode regulator that can handle 12 or 24 volt DC input. This will allow small sensor devices to hang off a typical bus network having extra pairs for the central power supply.

Thanks for your fast reply. That sounds easy. And you think that the communication between sensor nodes and Gateway are still possible via wired RS485? I tried to find an example on this site for sending Information from Gateway to sensor nodes. (via SendMessage ?) For example I like to Switch on/off an light that is connected to an relay board at my sensor node. Communcation Flow: OpenHab2 --> MQTT --> Gateway --> RS485 --> Sensor Node --> Relay Board Currently I have an working RS485 Connection between my Arduino Uno's with the use from SoftwareSerial library. During my testings I realized, that the message that I triy to send "Hello" will be sent to the other arduino char by char. Is that true? Because I tried to raise up an pin on HIGH with "if(msg == "Hello")..." But it doesn't worked. Will the sendMsg method from the MySensor library handle this out of the box? Regards, Simon

Hi PJR, now it is working with this code in the MyTransportRS485 without any changes on MySensors.h: #if defined(MY_RS485_SWSERIAL) SoftwareSerial& _dev = MY_RS485_SWSERIAL; #elif defined(__linux__) SerialPort _dev = SerialPort(MY_RS485_HWSERIAL); #elif defined(MY_RS485_HWSERIAL) HardwareSerial& _dev = MY_RS485_HWSERIAL; #else AltSoftSerial _dev; #endif As far as I can interpret the peace of code, the #include "hal/transport/MyTransportRS485.cpp" is active as soon as the MY_RS485 layer is defined. This is a great step, I can use all my nodes from now on! Thank you very much for your support! By Kduino

By the way I have done this with the icsc lib from majenko, if anyone is interested. The rs485 input is directly sent via udp and v v. Additionally I extended the icsc with an ack funtionality to keep track on lost messages on the bus. It runs currently with 57600 baud.

Today the new rs485 shield arrived, i will solder it up over the weekend and start testing early next week:)

Note that you can make use of any MAX485 module that is suitable for the arduino (5V). Basically they are all the same except for a few minor tweaks like LEDs or other non relevant stuff.

Hi, Have you seen the following: rs485-rs232-serial-transport-class-for-mysensors-org Is that what you are looking for?