Using a 555 timer, an 8-bit synchronous counter and an 8-bit R-2R ladder DAC, design and
construct a waveform generator that can be switched to produce the following waveform
outputs. Only three switches or less may be used.
The 555 timer frequency must be adjustable with a variable resistor so that the final
waveform output frequency range is 100 Hz to 1 kHz.
1. A sawtooth wave
2. A reverse sawtooth wave
3. A triangular wave