This is a function generator. I'd think that 3 digits of precision=20 would be pretty reasonable. The display would probably have more=20 digits of display but the lower order digits would be meaningless. The reason I want to use period measurements for lower-frequency=20 operation is to allow fast and easy setting of a frequency such as 60.2 Hz. dwayne At 06:45 PM 7/18/2014, Jean-Paul Louis wrote: >What resolution do you needs? > >Jean-Paul >AC9GH > > >On Jul 18, 2014, at 9:01 PM, Dwayne Reid wrote: > > > Good day to all. > > > > The recent discussion about controlling the frequency of a signal > > generator reminded me of a project that I've been meaning to do for > > years. But it's been sitting for so long that I should see if anyone > > has done anything similar to what I want. > > > > I have a couple of older BK Precision function generators. These > > cover the range of sub-Hz through, I think, 5 MHz. They work well > > but suffer one tragic flaw: it is not possible to know what frequency > > you are generating without using an external frequency counter or scope= .. > > > > I want to add a digital frequency readout to these units. There is > > space in the upper-left corner of the front panel that is just crying > > out for some form of readout. > > > > I've seen a couple of frequency meter projects over the past few > > years - most are simple and use a PIC's TMR0 and its' prescaler to > > measure a signal up to 50 MHz. But I'm picky. I want something that > > measures and displays frequency when the generator freq is above, > > say, 1 KHz but measures period and converts that period measurement > > to frequency at lower freqs. This allows quick display updates even > > when generating low-frequency signals. > > > > Bonus points if the unit can also measure and display period as well > > as both positive and negative pulse width. > > > > I could write it myself but surely someone has already done something > > similar to this. I hope. > > > > Any thoughts? > > > > Many thanks! > > > > dwayne --=20 Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax www.trinity-electronics.com Custom Electronics Design and Manufacturing --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .