PIC16F84_Variable Frequency and Amplitude Generator

This project is based on PIC16F84 Microcontroller. The system checks the variable resistance value and modifies the amplitude and frequency of the square wave. To simulate this circuit, initially activate Mixed Mode simulator from the Schematic Editor window. Simulation can be performed by selecting Run Transient analysis (Oscillograph) from Simulation menu.

This project includes PIC16F84, two variable resistances, ADC 0808, DAC AD8582, and Buffer 74ALS245A.

The two variable resistances are for changing amplitude and for changing the frequency of the square wave. Using the ADC 0808 both the values is read. DAC AD8582 converts the digital value of amplitude and time to analog waveform. Buffer 74ALS245A is used for switching ADC and DAC since we have only one 8 bit port.

The source code written in C language and can be viewed from the code editor window

The source code has to be compiled after making any modifications (editing). Also the code can be debugged during simulation.

Algorithm

1. Start

2. Selects channel of amplitude ADC

3. Reading the variable resistance values from ADC for amplitude.

4. Out the amplitude value.

5. Selects channel of time ADC.

6. Reading the variable resistance values from ADC for time.

7. Make delay based on ADC value

8. Display of varied frequency and amplitude in waveform viewer.

Iterate the loop for making a square wave.

Block Diagram:

The source code in the code editor window has to be compiled after making any modifications

(editing). Also the code can be debugged during simulation.