555 Timer As A Tone Generator
Once our window comparators give the output we need, we also need to have a way to generate a unique sound or tone to correlate with each of the 8 positions.
The circuit seen above is a generic a-stable multivibrator circuit. It outputs a pulse with modulation (PWM) wave which can be used to drive a speaker. The sound is a little dull and scratchy, but it works. Anyone who remembers MS-DOS video games will probably recall hearing these types of tones in many games.
If we change the value of R1, we will actually get a different tone pitch. So, if we connect up the 8 different logic signals from the window comparators to 8 different resistor values, which connect to the 555 timer, you'll hear a different sound for each of the 8 distances away from the IR proximity sensor.
Once our window comparators give the output we need, we also need to have a way to generate a unique sound or tone to correlate with each of the 8 positions.
The circuit seen above is a generic a-stable multivibrator circuit. It outputs a pulse with modulation (PWM) wave which can be used to drive a speaker. The sound is a little dull and scratchy, but it works. Anyone who remembers MS-DOS video games will probably recall hearing these types of tones in many games.
If we change the value of R1, we will actually get a different tone pitch. So, if we connect up the 8 different logic signals from the window comparators to 8 different resistor values, which connect to the 555 timer, you'll hear a different sound for each of the 8 distances away from the IR proximity sensor.