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Resolved: SoftwareSerial between two Jeenodes

Added by ulli over 6 years ago

Hi guys,

I have a strange issue.
I use two jeenodes which are connected to each other by using SoftwareSerial. (with very short wires)
The main node pushes the SoftwareSerial strings just straight to the standard uart and I see following:
fsk 1 92 05 52 6A FF
fsk 1 92 05 ¿5™ 6A FF
fsk 1 92 05 53 6A °B
™Sometimes I get wrong characters in the messages. Does anybody know why this happened?
You see the setting attached on this message.

Maybe the resistor which is used for the OOK signal decoding is disturbing the softwareserial?
Or do you see any other reasons?

Maybe the softwareserial is not a good solution….Is there a better way to transfer the commands between the two jeenodes?


Replies (5)

RE: SoftwareSerial between two Jeenodes - Added by ozzy over 6 years ago

Why not use the RFM12 connection ?. I have it working very well for transmitting outdoor temperature to a couple of nodes indoor.

RE: SoftwareSerial between two Jeenodes - Added by martynj over 6 years ago

ulli,

The receiving side is not framing the incoming character consistently. Provided the signal is “clean” (GND’s linked together etc.,) the most likely cause is the either side is not keeping to the bit time limit correctly.
You could try reducing the nominal baud rate, though it may not be effective because I suspect there is some conflict at interrupt time.
I believe Software Serial uses pinchange interrupts - these are non-latching, meaning if you don’t get to service the change fast enough, the pin state may already have changed again.

RE: SoftwareSerial between two Jeenodes - Added by ulli over 6 years ago

First of all thanks for the fast support!

ozzy: I can not use the RFM12 because one JeeNode is 433 and the other is 868.

martynj: I already connected the VCC and GND pin of both Jeenodes. I source the secound Jeenode with the other over one Port connector.
Do you think it ould be the same issue by using the I2C or Software SPI?

I will try reducing the baudrate…

RE: SoftwareSerial between two Jeenodes - Added by martynj over 6 years ago

ulli,

If there is a conflict for resources to service interrupts fast enough, I’d suspect it will affect whatever driver package is involved.
Is there some area of the OOK-adapted rf12 code that keeps interrupts OFF too long?

RE: SoftwareSerial between two Jeenodes - Added by ulli over 6 years ago

martynj,

you’re awesome! I reduced the baudrate and tried to reduce the cli…sei functions to a minimum and it looks good.

Thanks a lot!

Now I got everything running well on two jeenodes!

  • IR send + receive
  • heating valves (ETH) send
  • ITPlus (LaCrosse) temperature sensors receive
  • power plugs send +receive
  • and LEDs :)
    (1-5/5)