Roaders wrote: ↑
Fri Jun 24, 2016 6:58 am
I've just got my Sense HAT after waiting about 2 months for it to be delivered from china and am VERY disappointing with the temperature accuracy. I think that it is probably reading temperature at around 10 degrees too high.
What a waste of time and money...
That's basically what im doing with mine at the moment is trying to correct the data (just doing a huge ton of collecting at the moment).
Needing to buy a real themometre and possibly run it alongside a UPS one as well to see if i get same results after error correcting.
As some have said, it is unfortunate that the HAT is only 1-2cm off the main board... unfortunately the CPU is basically right under the pressure/humidity chips which do the temperature.
Some ways of dropping temp is having the pi on it's side to allow some air flow.
At the moment im playing around with something like:
Code: Select all
output = subprocess.check_output("cat /sys/class/thermal/thermal_zone0/temp", shell=True)
cpu = int(output)/1000
###Avg temp from humidity & pressure
Code: Select all
temperature = (sense.get_temperature_from_pressure() + sense.get_temperature_from_humidity()) / 2
^The above is very close to a 10 degree difference in general. You'll get roughly 40C cpu and an average of around 30C from sense HAT.
doing something like:
temperature = avg temp - (CPU - avg temp) #Basically minus the difference from the sense hat.
Theres another one of:
avg temp - ((CPU - avg temp)/5.466)-6
I dont understand exactly what the /5.466 is meant to be doing; the -6 brings it closer to realistic, this ends up usually 2degrees higher than the above formula.
But it does provide some 'fun' in trying to work our and error correct temperatures. The alternative is getting a female-male 40 pin GPIO so you can extend and move the sense hat away from the pi... but that kind of defeats the purpose of having a tiny pi (given you could of just added that to your normal PC).
I wont lie... it is a very odd set up, and i dont see how the one they sent to the international space station could of been of any valuable use, esp with the case they had which would of restricted airflow almost entirely.