Frequency Counter of AVR with LCD Display

The frequency counter project operates with 40MHz while integrating an 8-digit LCD display.

The device can be an optional offsets for use in a receiver or transceiver while having 10Hz resolution. It also contains a built-in digital voltmeter with 6 channels. Direct reading can be provided by dividing by 10 or dividing by 64 pre-scalers the VHF version of the device.

The frequency counter contains only three inexpensive ICs along with a regulator and three transistors. It operated at about 25mA from 6V to 15V DC. The LCD display is the most expensive single item in the circuit, which is an industry standard 16 × 2 dot matrix module. This can often be found used or at bargain prices. The circuit can be built using any prototyping technique since the parts are easily obtained. Designing the own PCB is an option since the prototype can be built on a small commercial strip board.

To remove jitter, high sample rate of 5 samples/sec or more is obtained while the circuit operates in low current single supply. For portable use, the counter can be operated from a small battery with optional PC telemetry.

Rest of the project