Hi! It’s me again. I want to precise one thing. Are there anyone here who have succesful working RS485 network without any issues? We are talking here about issues but maybe someone have fully working sensors network?

Hi! My nodes stops working random once a week, once a month etc. I now upgrade my nodes sketch with watchdog timers. But not with avr/wdt library but with some code i’ve found in the internet. I dont upload the code to nodes but I’ve checked that the watchdog function working as I set some delay() into sketch. Its not a problem that the node hanging, the problem is They don’t restarting it self.

There is one thing that we all need to try. When you using RS485 than you have power supply somewhere far far away from nodes. Longer power lines means higher inductance and far more noise on power lines. I think we need to try to put some 10 - 100uF electrolitic cap on all nodes (i have 10uF on each node) and few ceramic 100nF near the microprocessor on every node. If you use atmega328p you need at least 3 of 100nF caps ( i forget to put them on my nodes). I’we read that this 100nF caps are very big improvement in power supplying the atmega.

Hi! Everything working pretty well, but sometimes some random node stops to communicate and react for pressing buttons. I have watchdogs in every nodes so I think that only communication is hanging.. Is it possible that only altsoftserial library hanging inside arduino code ??

Jumping 0.8 immediately after switching the relay and sometimes rising very slow during the time when relay is on.

Hi, I have few in wall nodes mounted under the light switches. I have two relays and one DS18B20 in each node. When i'm turning light on, switching the relay, the DS18B20 readings jumping about 0.8 degrees celsius up. When I switch off the relay readings back to normal. Anyone have similar problems ? Sensors are away from from node board, relays etc. so it's not about the heat from atmega or relays.

@gohan No I can't operate it with button. Relays are not optoisolated, i don't isolate them because my node board are powered by 5V and i can't provide external power only for relays.

@sineverba I have some problems with my RS485 sensors too. They working for few days like a charm and than one of them stops sending and receiving data. Most of the time it happend when I click button and relay switch the light. My wiring is ok, i have pull-ups and pulldowns in the middle on master and termination on both ends. I have watchdog enabled

void before()
{    

wdt_disable(); // maybe redundant
wdt_enable(WDTO_8S);
// sensors.begin();

}

But even with that the node won't reboot so i think it may not hangs and only lost communication. Maybe its something wrong with AltSoftSerial lib ??

I should mention that I'm using OneButton lib to extend functionality of my pushbuttons for long press and double click. Maybe that library have some issues with AltSoftSerial or MySensors ?

Hello again. After a week of thinking and hard work i finally got RS485 network working very close to what I want. I've done everything like it was mentioned here before. Fully bus-like network, termination only on both ends of line and pull-up and pull-down on the gateway. I also change MySensors library to newest 2.1 beta branch. All nodes working very good for last month but some times one node hanging and I can't control it via OpenHab or built in switch. I don't know what cause this behavior. I turn on watchdog timers in every nodes and theoretically when node hangs, watchdog should reboot arduino after 8 seconds. Practically it won't reboot my node.. It seems like the node don't really hangs but the communication stops.. Is it possible that one node can loose connection while other nodes on the same bus/wires working like a charm ?

I don't know if it would help but openhab reconnects with the gateway when I change something in .things file and save it. Binding reloads and all starts to comunicate again.