Experiences, problems and questions

  • Not sure where to start, I have several things in mind...

    Maybe first a big thanks! It's an amazing and interesting project!

    Before mysensors I used Z-Wave (and custom stuff over WiFi), but I faced some problems with it and it costs much. It is closed source and for me not well documented enough. Many manufacturers seem to not test it in real environments (compatibilty to other products/range).

    Someone on domoticz forum told me he switched to mysensors, so I thought to give it a try.

    So far I built some nodes and got some experience. I'm using NRF24L01(+), gateway on a WiFi ESP8266, integrated into domoticz.

    Maybe some of the following questions I could answer by myself after research, but if you know it on the spot, I would be quite happy if you can share it šŸ™‚

    My problems/questions/experiences are:

    1. Some days ago a temperature node with DS18B20 reported 0.0Ā°C. This sensor was working for around a month. It for sure was 15Ā°C or more. I'm using DallasTemperature Lib v3.7.7. I think this is related to an invalid read of my temp sensor. After that it continued to work, but now it reports 2x S_DOOR with the first having V_TEMP in domoticz (probably correctly measured). How a S_TEMP can become a S_DOOR with temperature?
      1a) Is there any code implemented to restart the node automatically? What will happen if a SPI or IĀ²C connection needs again a setup()?

    2. I bought some chinese clones that did not work. Took me some hours to find out what's going on...
      2a) What about selling kits containing every needed component? Of course genuine parts for a fair price.
      2b) Is that possible if a third party will do it (license)?

    3. I setup a node with an BME280, feeded from 2xAA battery and a 1.8 to 3.3V chinese voltage converter. This worked for 1 day. Now it just sends one message after I press reset. (Lib Adafruit BME280 1.0.5) Anyone with similiar experience?

    4. I have setup a node (arduino pro mini) with 2x NTC resistors (actually bought DS18B20 but just got NTCs w/o datasheet...) and a DS18B20. Node is feed by 2xAA directly and stopped working after around 2-3 weeks. Sleep current is ~0.110mA. Current during transmission around 20mA. The DS18B20 just reported a value ~2-3 hours on a day. The NTCs were sending data more continuesly but now also stopped. (ok, might be I moved the node by 2 meters) Does this make sense?

    5. I flashed the node mentioned in 4) several times by a cheap USBasp without erasing the eeprom, but it got always a new ID. ID is stored in eeprom, no?

    6. If I add 1-2 repeater nodes will this make everything more stable and packets will find its path dynamically?
      6a) I plan to create some actuators (light switches). What happens if a packet is lost? What is the default timeout after a packet gets discarded?
      6b) Will a NRF24L01 with PA(+LNA) bring more stability?

    7. Does the NRF24L01 interfere with WiFi?
      7a) How to know about the channel and frequency it is using?

    8. If my neighbour is also using mysensors, will his new nodes be registered on my network? (I recommended him...:-))
      8a) Signing alone probably does not help here, or?

    9. Is there any congestion control implemented or does this happen a layer above on the NRF24L01 chip?

    10. Out of interest: Is there any rough estimation about how many people are using mysensors?

    I'm ready to create and share some new soft-/hardware. So far setting up all the stuff took a lot of time and I lost a bit of mood. Actually, I would have bought a ready solution, but I don't know of any satisfying my needs (except mysensors) šŸ™‚

  • Contest Winner

    @krisha Welcome to the MySensors community!
    For 8 and 8a: the gateway has an inclusion feature that will make it only accept new nodes in the network if the controller allows it for a certain period.
    You can either trigger it by a command from the controller or by a button press on the gateway (depending on your gateway configuration).
    Signing will not prevent nodes from "showing up" alone, but if your gateway and/or your nodes requires signatures, your neighbor will not be able to get messages through to/from your nodes/gw.

    If you use encryption, all your communications will be obfuscated and unreadable by your neighbor.

    You can also pick a non-default base address for your wireless communications to get your own "band".

  • Hardware Contributor

    Hello and welcome !

    1. No idea how node type can change. This has been reported by another user, it is a complete mystery to me as there should be a hardware level checksum. Maybe some clones don't implement that correctly, it would be strange, but I don't see any other plausible explanation.

    2. Don't be too cheap when buying modules. Most modules are fakes, but MySensors does well with most of them except the very cheap ones which should not be called "clones". You can buy reliable modules (and supposed to be made with real chips) from a few sources like CDEByte shop on AliExpress or Ebay, or Itead.cc

    3. Avoid step up converters, they usually are really noisy and create more problems than they solve. With BME280 you can go to a very low voltage (below 2V) so the best solution is to update the pro mini bootloader and fuses to remove the 2.7V BOD and set clock to 1MHz so it, too, can run down to a very low voltage. Then you can just power directly from the 2*AA.

    4. DS18 needs a minimum Vdd of 3V. Probably after 2-3 weeks the voltage of your 2 AA went a bit too low. Then it might make your code block. For battery powered nodes, use i2C sensors (bme280 or si7021) and forget about all those problems šŸ™‚

    5. Yes it's in EEPROM, probably it was reset somehow during flashing process.

    6. If you don't have a huge home, just get a PA/LNA module and you won't need any repeater and won't lose packets anymore. I like a few other people bought a PA/LNA module from CDEByte and I have not been disappointed: no more range problems, no more lost messages etc. And opposite to the cheaper PA/LNA modules on AliExpress/Ebay you have no foil wrapping and tinkring to do. Just plug it and enjoy your stable MySensors network šŸ˜‰

  • Hero Member

    @Nca78 have you got a link to the PA/LNA module from CDEByte , they sound interesting.

  • Hardware Contributor

    @Boots33 said in Experiences, problems and questions:

    @Nca78 have you got a link to the PA/LNA module from CDEByte , they sound interesting.

    This one :

    I have one with IPX antenna too, and it works very well with a IPX=>SMA adapter and a SMA antenna outside of the enclosure