Converts an RTTL ringtone into verilog using Python - and plays it back using differential PWM modulation
Provide 10kHz clock on io_in[0], briefly hit reset io_in[1] (L->H->L) and io_out[1:0] will play a differential sound wave over piezo speaker, different tunes can be selected by different tune_sel inputs
Piezo speaker connected across io_out[1:0]
| # | Input | Output |
|---|---|---|
| 0 | clock | piezo_speaker_p |
| 1 | reset | piezo_speaker_n |
| 2 | tune_sel0 | ledout_0 |
| 3 | tune_sel1 | ledout_1 |
| 4 | ledout_2 | |
| 5 | ledout_3 | |
| 6 | ||
| 7 |