Magic Mirror fire hazard.

dvcv

@Mykle1
So the mirror has been set aside for a while but I finally added the temperature module to it and these are the stats.

I have never left the mirror on for more than a couple hours because I was afraid of the heat. So the uptime of 7 hours is the longest its been on. Even without the pegboard, the pi is giving a temperature close to 80 degrees. Could this be because of a faulty pi?

cowboysdude

Well if it caught on fire you’d be the first… been running 3 of these without issue for a year… I’ve seen no signs of anything that would cause me to worry.

Mykle1

@dvcv

Are these the kind of results you get when running the default installation? Some modules will challenge the Pi more than others, thus increasing your system load and your system temps. Several of these together could easily be responsible for your current levels. Personally, I’d be worried about cooking the Pi but not necessarily a fire. Have you employed heatsinks and a fan?

pinsdorf

The CPU temperature is an easy start, but I don’t think that it gets you very far to assess potential fire hazard. Reason is that this value does not tell you anything about the temperature of the surrounding air. Bigger cases might be able to cope with the CPU’s heat while the air in smaller cases may heat up more/quicker.

Instead, I’d attach a DHT22 sensor and run the mirror for a couple of days (while I’m around). This sensor logs temperature an humidity, is pretty cheap, easy to connect, and well covered by the maker community w.r.t. libraries and documentation. You should place the sensor inside the case at the top, because warm air moves up as we all know.

There are a couple of modules showing the temperature from a DHT22 sensor on the mirror. This is nice, but gives you just a current value. Thus, it might be beneficial to log the data, visualize it in a chart and look at trends, max values over the day, time to cool down after shutdown, etc1.

Please have a look here for tutorial to achieve logging and visualizing DHT22 sensor data using Thingspeak:

Even simpler, you could periodically write temperature values to a CSV file on the RaspPi’s file system, copy this file manually to a PC, and visualize it in Excel. There are many tutorials for this. The following one seems to be focussed on the bare minimum without too may bells and whistles:
https://learn.adafruit.com/dht-humidity-sensing-on-raspberry-pi-with-gdocs-logging/overview

Have fun!

dvcv

@Mykle1 I have a few modules installed aside from the default ones. I do have a heatsink but no fan. So how does the fan work? Is it constantly on or do you have it programmed to turn on after a certain temp.

Mykle1

@dvcv said in Magic Mirror fire hazard.:

I have a few modules installed aside from the default ones.

Well, it really depends on the modules themselves. You could have 10 that have little affect on the Pi. However, you could have 1 or two that tax the Pi to it’s limits.

I do have a heatsink but no fan. So how does the fan work? Is it constantly on or do you have it programmed to turn on after a certain temp.

You can do it either way. Personally, I have mine on all the time. It keeps my Pi at a nearly constant 42°C. I prefer that to the temperature swings between it being on and off.