I've built this kit as a general purpose 6 digit LED display, 2 A/D 0-5V inputs could be made as a dual 3 digit display. Easy to make as a frequency counter too.
Dragonfly
**broken link removed**
It's got a microcontroller, a PIC16F886 or you can upgrade it and use a 18F2525. The 18F2525 has a TMR0 with enable / disable which would make it better suited for a frequency counter.
It's got two 10bit A/D inputs on the USER connector and with a simple resistor divider you could easily make it a dual display panel meter.
Yahtzee game, dice, clock, timer etc... Yep it's programmable and even has RS485
IT all depends on what you want to make and what volatge you want to read and how you want to display it.
You can have and LCD or 8 x 7 segememnt LEDS
just use an op-amp to devide the voltage say you want 0- 30 volts then use op-amp to devide it to 0- 5V. then send the data out
If you used a GLCD then you can have upto 8 channels
or use a max7219 seven segment driver
here is a link for one