Here is another modification of a digital voltmeter. This time with 7 – Segment LED Display. These circuits seems to be more popular than other designs so I’ve decided to publish another variant. You can find 4 variations of digital voltmeter on this site under Projects –> Digital Voltmeter. For Arduino based LCD voltmeter click here. Present version has the same characteristic as a VFD version available here. Due to multiplexing routing used to drive the LED’s you may notice a slight digit flickering during display update, however it’s barely noticeable. In the next figure you can see a design schematic.
During the testing I have found a slight shift in measured values above 10 Volts probably due to the use of standard resistors in voltage divider construction. 0.1% precision resistors should reduce this shift.
MPLAB-X project files and C source code are available at this link. Feel free to modify the code according to your needs. If you have any questions please contact me and I’ll do my best to help.