A weblog focused on interesting circuits, ideas, schematics and other information about microelectronics and microcontrollers.
PIC frequency counter
A small frequency counter with a cheap PIC microcontroller and a few seven-segment LED digits with frequency range up to 50MHz.
Yes, I know - frequency counter is the second (well, maybe the third) device we all built in our microcontrollers beginnings... But this one is really interesting: It measures frequencies up to 50MHz without the prescaler / external counter / whatever (a little quis: Do you know why this counter can't be ported to the AVR?).
Here are the features:
# four or five digits resolution (display for example x.xxx kHz, x.xxx MHz, or xx.xx MHz); or 6 digits with F8FII's modification
# automatic range switching with different gate times
# optional addition or subtraction of a frequency offset (programmable)
# optional preamplifier for the input signal
# can be built on a single-sided 'breadboard-style' circuit board
# firmware available for common-cathode as well as commom-anode displays
# very low component count: a PIC 16F628, 4 or 5 7-segment LED displays, a 4- or 20-MHz crystal and a few resistors