How to measure the energy performance of Raspberry Pi against a task?

Question

I want to measure the energy consumed while performing a repetitive task on a Raspberry Pi. One example of my usecase is measuring the energy consumed when I am sending 10,000 data packets/min to a server. And then compare the energy consumed when sending 1,000 packets/min. Are there any software tools which can help to achieve the objective?

Answer 1

doesn't work since RPi lacks the power gauge hardware. Still, may be useful for people running different SBC brands

I would start by logging /sys/class/power_supply/*/current_now every ten seconds or so. You may want to replace the star by whatever the power supply device is called on RPi. A simple script would do:

for i in {1..360}; do
    cat /sys/class/power_supply/*/current_now >> log.txt
    sleep 10
done

This script would run for an hour (3600 seconds), so keep sending your data packets during that time. Then you can simply take the log file, compute the average current (it'll be in micro-Amperes, so divide by 1000000), multiply by 5 Volts and voila - you have the energy consumption in W*h.