Recent content by theidealist

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    Controlling Rs485 slave devices (heater, pump, SWG) directly with Pi

    I realize I posted the above at a potentially particularly inopportune time for a number of users here. I hope you and your families (and your pools!) are all okay! l hope it's okay to give this thread a "bump" in the hopes that there's someone out there with some ideas, because I am out of...
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    Controlling Rs485 slave devices (heater, pump, SWG) directly with Pi

    Okay, so it's been two weeks since I've posted, but I haven't given up yet! However, I still haven't been victorious in getting the RS-485 connection to provide sensible data. Based on the generous help and input from @superuser and others, I performed the following tests using my multimeter...
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    PXL_20210214_003721763.jpg

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    PXL_20210204_025054382.jpg

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    PXL_20210204_025213780.jpg

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    PXL_20210204_025035837.jpg

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    Controlling Rs485 slave devices (heater, pump, SWG) directly with Pi

    Thanks for this suggestion! That does look way easier than I thought it would be. I'm hopeful I can bend the RS-485 bus to my will, but this is a nice back up plan.
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    Controlling Rs485 slave devices (heater, pump, SWG) directly with Pi

    Wow, thanks for all the great suggestions! I'm out for the next few days but will get back on this next week and report back. Thanks for the detailed advise here, @superuser! I do have a multimeter and can test this! I don't know if my adapter is terminated, but can do the test you...
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    Controlling Rs485 slave devices (heater, pump, SWG) directly with Pi

    Okay, so looking at the bytes being returned again, it really does look like random noise, maybe with some underlying oscillation (maybe why we get semi-regular packet sizes). For documentation purposes, my next plan of attack is: Get out the voltmeter and see what the Jandy voltage is VCC to...
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    Controlling Rs485 slave devices (heater, pump, SWG) directly with Pi

    This is a great idea, thanks! One of my goals here was to be able to control the temperature remotely, so that I can keep the (indoor) pool temperature colder most of the time when we're not going to be swimming in it but have a way to tell the system that we'll be swimming in a few hours so...
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    Controlling Rs485 slave devices (heater, pump, SWG) directly with Pi

    Thanks for the suggestion! Unfortunately, I see no real difference (other than the number of bytes per "packet"). I conducted an experiment trying each of SEVENBITS or EIGHTBITS, at each of 4800, 9600, 19200, 38400 baudrates. There wasn't a clear winner 🤦‍♂️ The results...
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    Screenshot from 2021-01-25 17-26-13.png

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    Controlling Rs485 slave devices (heater, pump, SWG) directly with Pi

    Made a bit more progress on this. I'm now able to read the data from Python, which I was having trouble with before. Unfortunately, the data does not make a ton of sense to me: $ ./jandy_heater_control.py Opening rs485 serial connect on port /dev/ttyUSB0 Read the next packet. It was 748...
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    Controlling Rs485 slave devices (heater, pump, SWG) directly with Pi

    Okay, so made a little bit of progress on this last night, thanks to @superuser for the suggestion. After I tried disconnecting the VCC (Red) and, then, also the Ground(Black) wires, I still got nothing. Then I had a thought that maybe RS-485 wires aren't color coded. So, maybe...
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    PXL_20210118_215213820.jpg