Skip to content

Instantly share code, notes, and snippets.

@ecampidoglio
Created February 21, 2013 23:42
Show Gist options
  • Save ecampidoglio/5009512 to your computer and use it in GitHub Desktop.
Save ecampidoglio/5009512 to your computer and use it in GitHub Desktop.
A Bash script that prints the current state of the CPU on a Raspberry Pi. It displays variables like temperature, voltage and speed.
#!/bin/bash
# cpustatus
#
# Prints the current state of the CPU like temperature, voltage and speed.
# The temperature is reported in degrees Celsius (C) while
# the CPU speed is calculated in megahertz (MHz).
function convert_to_MHz {
let value=$1/1000
echo "$value"
}
function calculate_overvolts {
# We can safely ignore the integer
# part of the decimal argument
# since it's not realistic to run the Pi
# at voltages higher than 1.99 V
let overvolts=${1#*.}-20
echo "$overvolts"
}
temp=$(vcgencmd measure_temp)
temp=${temp:5:4}
volts=$(vcgencmd measure_volts)
volts=${volts:5:4}
if [ $volts != "1.20" ]; then
overvolts=$(calculate_overvolts $volts)
fi
minFreq=$(cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq)
minFreq=$(convert_to_MHz $minFreq)
maxFreq=$(cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq)
maxFreq=$(convert_to_MHz $maxFreq)
freq=$(cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq)
freq=$(convert_to_MHz $freq)
governor=$(cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor)
echo "Temperature: $temp C"
echo -n "Voltage: $volts V"
[ $overvolts ] && echo " (+0.$overvolts overvolt)" || echo -e "\r"
echo "Min speed: $minFreq MHz"
echo "Max speed: $maxFreq MHz"
echo "Current speed: $freq MHz"
echo "Governor: $governor"
exit 0
@mcgyver83
Copy link

On a raspberry pi2 I have this error executing this script:
cpustatus.sh: 23: cpustatus.sh: Bad substitution

@ThomasKaiser
Copy link

/sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq is wrong unfortunately! Don't trust in it if you're interested in CPU clock. This is controlled by the 'firmware', the kernel has no clue at which frequency the CPU cores are running and you need to query the firmware with vcgencmd measure_clock arm instead especially if you're interested in overclocking.

bamarni/pi64#4 (comment)

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment