Simple AC voltmeter
I had long been thinking of designing a simple AC voltmeter but had somehow never gotten to it. However, with school just ending, and me going back to electronics, this was a neat simple yet useful circuit that I felt I could just get done with in a day or two. The concept is fairly straight forward. Since I needed this only to measure the mains AC voltage and the output voltage of the sine wave inverter I was working on (based on the PIC32MX250F128B - more on this later), I didn't need to do any "true RMS" measurement. All I had to do was to convert the mains AC to DC, filter it and measure the peak voltage. Of course this had to be scaled down to a safe range for the microcontroller. The RMS voltage for a sine wave is equal to 0.707 (to 3 decimal places) the peak voltage. The design was based on the Microchip PIC16F676. However I realized that I didn't have any in stock with me. So, I just used the pin-compatible PIC16F684. On the software side of thin...