PIC frequency meter and voltmeter

PIC frequency meter/voltmeter

Frequency measurements up to 50MHz

Power supply voltage measurement range: 0.0 V - 25.5 V

The input voltage at both analog input terminals is measured and simultaneously displayed as a bar graph (PWR/SWR or S) indicator.

The input sensitivity can be selected between 0.25V, 0.5V, 1.0V and 2.0V to achieve maximum bar graph indication.

This is the successor to the PIC16C71 4-digit LED frequency meter and voltmeter.

Some hard-to-find parts used in previous versions have been omitted because they have been discontinued for some time.

The earlier PIC16C71 was replaced by the 28-pin device PIC16F876.

The latter can drive a 4-digit LED display in multiplexed mode, simultaneously measure frequency and power supply voltage, and process two analog inputs to display the SWR/PWR signal strength in a bar graph format.

Since it is built into the PIC16F876, no external digital tube driver chip or external data EEPROM is needed.

The reduced number of chips used also makes the counter smaller than its predecessor.