I have installed LineageOS using PINN on my raspberry pi 3 and it runs fine, but I started worrying about high temperature. You see, when I use Raspbian or RecalboxOS, it warns me with a temperature icon when the temperature is too high. When I am using Lineage, I don't get any under voltage warning, probably meaning that I won't get high temperature warning too. So, is temperature controlled by hardware or software? If it is controlled by software, then I will need to be careful.

  • Just an aside comment, if the CPU is getting that hot, if you haven't already, you should consider putting a heatsink on it to avoid the problem entirely. There are lots of low cost stick-on heatsinks that you can find with a google search. – crj11 Feb 20 '18 at 16:31

Temperature warning is conrolled by the Raspberry Pi firmware.

If the temperature of the SoC is between 80C and 85C, you will see the "Over temperature warning". If the temperature of the SoC is over 85C, the ARM core(s) and the GPU will be throttled back in an attempt to reduce the core temperature.

source: Raspberry Pi Documentation, Firmware warning icons


Whilst hitting the temperature limit is not harmful to the SoC, it will cause CPU throttling. A heatsink can help to control the core temperature and therefore performance. This is especially useful if the Pi is running inside a case. Airflow over the heatsink will make cooling more efficient. [..]

With firmware from 12th September 2016 or later, when the core temperature is between 80'C and 85'C, a warning icon showing a red half-filled thermometer will be displayed, and the ARM cores will be throttled back. If the temperature exceeds 85'C, an icon showing a fully-filled thermometer will be displayed, and both the ARM cores and the GPU will be throttled back.

source: Raspberry Pi Documentation, Overclocking options in config.txt

  • What happens if throttling back doesn't help? Does it power off? – user81004 Feb 21 '18 at 4:54
  • @ÖmerRıfatKuldaşlı regarding your comment "What happens if throttling back doesn't help? Does it power off?" I don't know the answer. I would like to suggest to open a new question for this topic. If your RPi is getting that hot, you might want to install a fan for better airflow. All my RPis with heavy workload have a fan and average cpu temperature is less than 37°C (inside office with human friendly ambient temperature). These fans are inexpensive and do a silent job with 3.3 volt. – Fabian Feb 21 '18 at 14:04
  • It doesn't get that hot, I just wanted to know so I could prevent it – user81004 Feb 21 '18 at 14:05
  • its a good question, go for it – Fabian Feb 21 '18 at 14:05
  • crosslink to the follow up question: raspberrypi.stackexchange.com/questions/79562/… – Fabian Feb 22 '18 at 13:15

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