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bruhautomation / ESP-MQTT-JSON-Multisensor

(OBSOLETE) ESP MQTT JSON Multisensor for Home Assistant. Supported sensors include the TEMT6000 light, AM312 PIR, DHT22 temperature/humidity sensors. RGB led supports flash, fade, and transition. Over-The-Air (OTA) uploading, too!
https://youtu.be/jpjfVc-9IrQ
Apache License 2.0
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Getting very inaccurate temperature readings #15

Open TheFitzZZ opened 7 years ago

TheFitzZZ commented 7 years ago

Hey guys,

I have six of the sensors around the house, some also where already other sensors exist, so I can compare the results. Something I don't really need another sensor for is the fact, that the remperature is off by some extend. It's always way too high by 5-10°C - same error with °F btw.

Any ideas what could cause this? It makes them practially useless.

Thanks

tariquesani commented 7 years ago

Do you by any chance have DHT11 rather than DHT22

TheFitzZZ commented 7 years ago

No, but I think I see the issue now: the case (the 3D printable one included here). I think it heats itself up and the ventilation by the few left-outs isn't enough by any chance to get proper readings.

How I know this? I aimed a little USB ventilator at the box to get some airflow. And voila, the temperature seems much more likely to be correct: went from 31°C to 24° - which seems reasonable.

I will verify further, design a new case and make a pull request for it once I've tested it ... will take some time though :-)

bruhautomation commented 7 years ago

Yeah, in doing some testing with this tonight. It does appear that the case is causing the heating issues. Sorry about that! You could add an offset in the code, but that's not a great solution. I'm going to redesign the case and move the sensor further from the board. That should help.

@TheFitzZZ, if you come up with a new case design, too. I'd be happy to post the link or host the STL in the repo if you want!

Cheers!

gillrishi commented 7 years ago

Hi I am using dht11 sensor. it shows temprature 987 c and humidity 1098%. Can you help me out to fix this issue? Thanks

tariquesani commented 7 years ago

@gillrishi get a dht22

gillrishi commented 7 years ago

Ok.. Thanks for your help

bruhautomation commented 7 years ago

Yeah DHT11 sensors aren't as great. If you use a DHT11, make sure you set line 73 to

#define DHTTYPE   DHT11

Cheers!

cbrherms commented 6 years ago

Looks like the V2 case might be doing something similar though. i'm getting about 5C difference even on the new case.

martinjuhasz commented 6 years ago

Same here, its related to the case (I'm using a custom one, but still with the sonsor attached outside to the case). Having the sensor some cm away from the encasing shows me the correct temp.

Any ideas what we can do about this?