Add even more versatility to your workshop facilities with this PIC-based frequency generator/counter.

Combining the sophisticated features of a Maxim MAX038 waveform generator and a PIC16F877 microcontroller has resulted in a highly versatile and inexpensive workshop tool whose facilities have hitherto been unattainable without considerable design complexity.

The MAX038 is a high-frequency precision function generator whose output is selectable to produce triangle, sine and square waveforms, within a wide operating frequency span of 0× 1Hz to over 10MHz, split in the PIC-Gen as eight overlapping frequency ranges. Range and waveform selection are performed by the PIC16F877 in response to pushbutton switch controls. Frequency is fully variable within the selected range by means of a front panel control potentiometer.

An alphanumeric liquid crystal module displays the frequency and range information. Four frequency outputs are provided:

• Direct output at ± 1V peak-to-peak
• AC coupled output, fully variable between zero and 4V peak-to-peak
• Pulse output, 0V to 5V logic level
• 3× 2768MHz fixed frequency, 0V to 5V logic level

The PIC is also used as a frequency counter, switch selectable to monitor the frequency generated by the MAX038, or from an external source in conjunction with a pre-conditioning waveform shaper and frequency divider. Two external signal inputs are provided: one for 0V to 5V logic level waveforms, the other for AC waveforms having a peak-to-peak swing of between about 2V to 5V. The prototype can monitor frequencies in excess of 40MHz.