The more I use PWM the more I like to understand it and monitor its duty cycle and timing etc. For this reason (and although 3 of my multimeters are capable of measuring PWM duty cycles and frequemcy) I decided to build my own PWM monitoring meter.
Yes I know the case is all scratched up and stuff but its practical and small. I still have a few finishing touches to add to the meter like a power socket and input socket but the unit is 100 percent working.
The first prototype was built on solderless breadboard and worked wonderfully. This unit is however built using a barebones Arduino Pro Mini 5V and LCD and a few other bits and bobs.
I made up the veroboard on the back of the LCD to control LED current through the backlight LED’s as well as contrast and also to allow a single DC input to the display. The Arduino Pro Mini is mounted to the bottom of the case and the mode select button and power switch below the LCD.
The Unit turned on displays the current frequency and duty cycle. With it floating it seems to pick up the 50hz ac signal. :-P
By pressing the mode button you can cycle between modes.
Now there are still a few thing I need to do to complete this meter but as with anything it is a work in progress. A practical one at that. :-)
This project has been seriously upgraded to include a digital PWM signal generator, a lighting controller as well as the user interface for my home automation system and therefore has many more buttons on board. It is also controllable from the PC where I have written some software in visual c# as a user interface. Information to follow soon.
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