Temperature variations

How useful is this MQTT-SPY turning out to be – I had no idea I had such temperature variations from my DS18B20 – ok it looks worse than it is due to the limited range of the graph but I really do need to do some averaging!! This is just 1,147 readings at 5 second intervals. No way I would have spotted this without this easy to use (and free) software… now I sound like an advert.


graphing MQTT SPY


3 thoughts on “Temperature variations

  1. Pete,
    I’m going to beg your indulgence here… this comment is MQTT related, but not about MQTT-SPY, so please feel free to delete it (or, hopefully, move it elsewhere if you don’t find it too offensive :-)).

    There’s been a nasty little problem lurking with the esp_mqtt package and -some- Linux installations of MQTT for about a week to ten days now which, to be honest, I thought was specific to my cack-handed C coding. After integrating a ton of my crap code back into the latest pull of Tuan’s package, my ESP became unable to connect to the mosquitto broker. It could talk to the server fine, open a connection to port 1883 and initiate the connect, but it always failed and then immediately restarted a reconnect cycle (ad infinitum). The mosquitto server also spewed out messages saying “Invalid protocol `MQTT’ on CONNECT”. WTH? Mosquitto thinks MQTT is an invalid protocol?
    After a few days of on-and-off work, trying to find my mistake, I finally pulled a clean version of esp_mqtt, pointed it at the server and, no surprise, got the same error. But, I knew the mosquitto installation hadn’t changed in any way …and yet there wasn’t anything posted on the ‘net (that I could find) from other esp_mqtt users complaining that their ESPs had suddenly stopped working. Again, WTH?
    It turns out that Tuan updated esp_mqtt to be fully 3.1.1 compliant when he was working on the LUA integration. Not really a problem, as 3.1.1 has been around for a while now and is pretty much the default. What bit some of us Linux users though, is that the version of mosquitto available from the Software Centre on Ubuntu based distributions (and tagged as “MQTT 3.1/3.1.1 compatible”) is a really ancient 0.15 revision and, despite the tag, is actually only 3.1 compliant. Duh!
    As usual, Tuan responded really quickly and rolled out a fix in just a few hours, so if anyone else is dead in the water with these syptoms, you can pull the latest package and modify the protocol define in the /include/user_config.h file:-

    #define PROTOCOL_NAMEv31 /* MQTT version 3.1 compatible with Mosquitto v0.15 */
    //#define PROTOCOL_NAMEv311 /* MQTT version 3.11 compatible with Paho & Mosquitto > v0.15 */

    That’s the quick fix.

    I’ve also put up a post at https://esp8266hints.wordpress.com to explain how to update your Ubuntu Update Manager to use the up-to-date repository which Roger Light has already provided on the mosquitto site and
    automatically update your version of mosquitto to whatever is the latest and greatest.

    Hopefully this will save someone else’s walls from all of those dents (from head banging).

  2. I agree. I have DHT22 connected to Arduino connected to ESP8266 and only sending out MQTT message when there is a change in values. I kind of knew I have to improve on my code but this charting makes it very easy to study the variation of the change even with 3 hours worth of data. Looks like weekend will be spent in finding out why there is too much variation at some point then no change and then again lot of changes. Maybe my circuit is unstable.

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