Raspberry Pi, heat & crashes

[sdevijver]

I bought my RPi from RS components. I've installed Xbian version 1.0a4. My RPi would crash a couple of minutes after booting.

Then I discovered that removing the top cover of my case improved the situation. Now it would reboot after 10 minutes to half an hour. When I played a movie however it didn't last more than a couple of minutes.

Then I discovered that Xbian by default overclocks the system. I restored the defaults and still with the top cover removed it didn't crash anymore. It could now play a 50 minute video repeatedly without difficulties.

In the meanwhile I had installed watchdog. When I put the top cover back on the case my RPi would reboot every 15 to 20 minutes, while being idle in the XBMC home screen and still with the default overclock values. I has also added my own script to track the CPU/GPU temperature when my unit crashed. It fluctuated between 42C and 45C. Here is the script that I configured in crontab to run every minute:

Code: Select all

#!/bin/bash

CURRENT_TEMP=`cat /sys/class/thermal/thermal_zone0/temp`
UPTIME=`cat /proc/uptime | awk '{print $1}' | awk 'BEGIN {FS="."} {print $1}'`
TIME=`date +%s`
BOOT_TIMESTAMP=$(($TIME - $UPTIME))
BOOT_TIME=`date -d @$BOOT_TIMESTAMP +"%d-%m-%Y_%H-%M"`

PREVIOUS_TEMP_FILE=~/log/temp_log_${BOOT_TIME}.previous
TEMP_FILE=~/log/temp_log_${BOOT_TIME}

if [ ! -d ~/log ]
then
  mkdir ~/log
fi

if [ -f $TEMP_FILE ]
then
  mv -f $TEMP_FILE $PREVIOUS_TEMP_FILE
fi

echo $CURRENT_TEMP > $TEMP_FILE

Then I added a 12V fan connected to the 5V GPIO pin and I also restored the default xbian overclock values. Now I can play the same 50 minute video repeatedly without any difficulties. The core's temperature is now ~34C.

This is the Xbian config.txt:

Code: Select all

arm_freq=840
core_freq=375
disable_overscan=1
gpu_mem_256=100
gpu_mem_512=100
sdram_freq=400
over_voltage=0

This is my config.txt where I restored the RPi default overclock values:

Code: Select all

arm_freq=700
core_freq=250
disable_overscan=1
gpu_mem_256=100
gpu_mem_512=100
sdram_freq=400
over_voltage=0

Conclusion: your overclocked RPi may work fine without cooling in a closed case but mine doesn't.

[drgeoff]

You may have a faulty RPi like some people in http://www.raspberrypi.org/phpBB3/viewt ... 28&t=20657 and other threads. Although the cause may be thermal, it is not necessarily overheating that is the issue.