@mick Thanks for coming back to this topic, the stuff arrived already some weeks ago, but unfortunately I was busy with other parts, amongst them btw. a modification of the MySensors plugin for FHEM to get probems shown more easily. So finally some soldering work was on my list yesterday. So today there's the option to at least give some first impressions on that:
- Network is @57600 for the use of the TJA1050 modules.
- Soldered some adopter boards for direct replacement of the modified LC-Tech MAX487 modules, (crossed RX/TX as usual, there's no DE/RE, later also desoldered the 120 Ohm resistor)
- plugged it in Node_2's socket, and
WOW: It worked!
Tried a second one on the same node (module without the 121R): Also worked
So I continued and tried to teplace the transceiver at Node_3 with the tested (now resistorless) one:
Continued with the last transceiver in line holding the pullup/dow resistors: Also no luck
So I decided to stop at that point to see how Node_2 will perform over night and meditate on the question why the behaviour on the other two nodes is different. Kept Node_1 and Node_4 not connected to the bus, so starting the experiment just with 3 nodes and the GW online.
This mornings's findings:
- (Node_2 hat at least once spontanously rebooted, but still was sending in data. I's rate this as some kind of partly success, but obviously the node needs to be reviewed, there most likely exists a problem not related to RS485.)
- (Node_5 was offline for whatever reason, no issues - as always - on Node_3)
- These transceivers can be used for MySensors@RS485
- They can be used in a mixed network together with normal transceivers
- BUT: (hypothesis) They may not be used in combination with altSoftSerial; Node_2 is HW-Serial, the other two still use software, so for them DE/RE might be essential (ISR?)
Additional remarks: I tried also a different power source for the 12V a couple of weeks ago - no difference (MAX487-only bus)
The GW was online during all of the time, it's uptime is 7 days by now (also SW-serial).
So I'll have to do some more testing on some of the topics and perhaps also build some more test nodes to avoid touching my "normal" bus too often - this seems to also cause additional trouble...
I'll come back when I know more, but again, this will take some time.
@bakcsa Thanks for this great summary!