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One of my aqara sensors suddenly stated that the temperature in the garage passed +650 degrees.. I checked, and it wasn't. 😉
Both humidity and pressure is reading normal levels - i guess this must be a HW error?
Its not dead either, just severely offset:
13d464d7-8a77-4740-95bf-6ed3a59515b8-image.png -
After researching a number of various Zigbee solutions, I have come to the conclusion that Deconz with a ConbeeII is probably the best one available, covering the two HA1.2 stacks and ZLL stacks with the widest compatibility range, even better than the ZHA or Zigbee2MQTT components of Home Assistant, and also the best maintained with regurlar firmware updates. It is really an equivalent to z-way but for zigbee. It has a rest API so I am dreaming awake of a bridge for openLuup here...
deCONZ REST APICould be a good project? I may get one to play with... It could potentially enable unifying the hue devices into one network.
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2.4Ghz band Zigbee, WIFI, BT, Microwave, Cordless Phones Interferences. What Zigbee channel to pick?
Kicking off this section with a quick write up on Zigbee 2.4GHz channel utilization.
Zigbee has become a very popular protocol over the past few years mostly due to its low power consumption, low chip cost (not being proprietary like z-wave was) and ease of inclusion.
It does come with a couple of downsides however ranging from single controller topography (aka single PAN coordinator) to what the title says: It uses the 2.4GHz (ISM) band which is possibly ultra saturated by other wireless protocols and even a variety of other more or less proprietary zigbee stacks. (i.e philips hue, Ikea Tradfi, Xiaomi, Plantlink etc...)
It is therefore important to make sure they don't interfere with one another.This is a good article showing the correspondence between Zigbee and WIFI.
ZigBee and WiFi Coexistence ZigBee and WiFi CoexistenceZigBee and WiFi channels both exist in the 2.4 GHz band, existing in the exact same frequency space. When deploying both WiFi and ZigBee in the same environments, careful planning must be performed...
Interferences lead to range reduction, dropped packets, more retries and lags. I have a 2.4GHz spectrum analyzer I can post some results from. I read through the zigbee alliance presentation claiming low interference but my experience demonstrates quite the opposite. When I was using SonosNET and Hue at the same time on neighboring channels, playing SONOS would kill the philips hue network.
Sudden offset in temperature reading
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One of my aqara sensors suddenly stated that the temperature in the garage passed +650 degrees.. I checked, and it wasn't.
Both humidity and pressure is reading normal levels - i guess this must be a HW error?
Its not dead either, just severely offset:
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strange indeed... seems like a hardware problem!
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Took out the battery for a moment, and now its back.. Just a "senior moment" (well, 10 hours) i guess!
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..and now its back at 655° again.. order a new one i guess..
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If it's suppose to be around 65F° then it it could be a notation error. Mixing up decimal points and decimal comma
US notation 65.5 would result in 655 when the notation is not set to imperial. E.g. EU notation is 65,5.
Still doesn't explain why it changes all of the sudden though.
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Hm! It wasn't that, but rather when it goes below 0° C! (cold in Norway)
I'll throw one of the others outside to see if the same happens, mabye its a flaw in the zigate plugin? -
Sounds like a signed value is being interpreted as an unsigned one, so the MSB is set when the temperature goes negative. I’d guess that a 16 bit value is scaled so that 32768 = 327.68 degrees. This would also be consistent with the UPnP standard representation of temperature being in units of 1/100 of a degree.
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..And this is done in the plugin, i presume? Seems like all message handling is done there in zigbee?
I'll have a look at the code tomorrow.. -
If it’s as I think, then the fix is easy... if the value exceeds 327.67 then subtract it from that number.
