A CPU Busy-Meter for Microcontrollers
When you’re using a PC, if you’d like to know how much you’re stressing your CPU, you can pull up this information with a few clicks of a mouse. On the other hand, how stressed is your Arduino or other development board? Usually we have no idea, but as Dave Marples shows in his Embedded Rambling post, this type of monitoring is actually fairly easy to implement.

His concept takes the fact that since microcontrollers generally loop through a series of commands over and over, you can insert a command to turn on an LED when it’s actually doing something, and turn it off when idle.
Since on/off cycle happens extremely rapidly, this can be used with an LED for a PWM effect (pulse-width modulation) to give you a quick reference as to your system’s load. This signal can also be setup with a series of resistors and capacitors to output a voltage proportional to the load in order to allow a numerical reading via a voltmeter.


