RSSI affects Sleep Timer??

  • This seems really strange! I have a battery powered project using an Arduino Pro Mini and an RFM69 radio. It operates a servo that opens/closes my Venetian blinds.
    I have it set to smartSleep for 5 minutes (sleeptime = 600000) between cycles to reduce battery drain. It works great in my workroom where it is within a few feet of the gateway and RSSI is about -45 but as soon as I take it up to the the living room where the RSSI is around -85 the unit only updates every 25 minutes. Bring it to the workroom again and it immediately reverts to 5 minute cycles.
    I thought -85 was still a reasonably good level as I do not require high bit rate transmission. And even so, how can the RSSI affect the sleep time?
    The MySensors code is version 2.3.2 and I am using a serial gateway.

  • I don't have a good answer, but since it's still a multiple of 5, I would assume that it's simply missing the other packets, and your sensor really is waking up and attempting? Maybe set it to require a response from the gateway before going back to sleep?

    Just a guess.

  • 600000ms is 10 minutes 😉
    Perhaps messages gets lost in the other room?

  • Thanks, the 600000 was a typo. Should have read 300000.
    I finally got time to set up a terminal on my laptop so I could capture the serial monitor output from the node and then processed that with the log parser.
    I could see the node repeatedly attempting to find parent, failing, and incrementing the "transport failure counter", waiting 10 seconds, then trying again. There was also a sequence where 4 failed find parent attempts incremented a "consecutive failure counter". And another where it incremented a "failed uplink counter". I also saw the node initiating the 5 minute sleep interval however the pre-sleep message also failed and hence the node never did get to snooze, it just went back to finding parent. After a fair amount of analysis I was not able to determine what was "special" about the instance when it actually connected or why it occurred at roughly 5 times the normal sleep interval.
    I reviewed the MyTransport section of the API documentation but could not find any details that helped.
    In the end I lost interest as I decided to just reduce the modem bit rate to the point where the radio would connect reliably. I was surprised to see the node connecting with RSSI as low as -106 dB ( at a bit rate of 2400/4800).

  • thanks for the feedback

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