We have several Raspberry PI 2 devices running balenaOS and connecting to an openBalena server. The devices run fine until the ambient temperature increases like in summer time. Then there are unexpected restarts of the device every few minutes. We tried to monitor the cpu temperature (/sys/class/thermal/thermal_zone0/temp) but in most cases, the cpu temperature does not overshoot 50°C, what should be not a problem for the Raspberry PI. We even tried the newest balenaOS 2.113.18, but it makes no difference. We have the problem on all Raspberry PI 2 devices and it is easy reproducable when running a Raspberry PI 2 e.g. in a closed box.
Any ideas?
hey there @r.krucker the first thing that comes to mind here is the power supply - have you checked that? How are you powering them? It could also be another component that’s overheating, not necessarily the CPU.
Thanks for the hint. We measured the voltage once on the GPIO pins and once on the usb cable. On both we have seen the same behavior. When the Raspberry PI runs, we had a nearly stable voltage arround 5.2 V. When the issue happened, we saw a voltage swing from 4.98 to 5.2 V. Maybe a component on the board cause that voltage swing when it gets warmer. Or has it to do with the throttling of the CPU?