This demo uses 3 preloaded samples to play audio under user control. Samples are loaded into ECP5 block RAM so preloading onto flash isn't necessary. The samples are about 30kbyte total so the ECP5-12 should be capable of running this demo too.
It includes 2 modes:
- Manual control using user buttons to play different notes and samples.
- Automatic control using a simple integrated tracker
make ulx3s_prog
These buttons marked on the board are used for control:
- 1: Start tracker playback (loops automatically)
- 2: Stop tracker playback
- 3: Change selected sample (piano, steel drum, square wave)
- 6 / 4 / 5: Play keys C, D, E respectively
- 0: Change current octave
Output is currently sent to the headphone jack. It's pretty noisy so in the future SPDIF / HDMI output may be added for cleaner output. The VOLUME parameter can be used to reduce volume if needed.
Output is sent to the headphone jack in both analog / digital form (SPDIF).
- Headphones can be plugged in directly to hear the analog output but it's a bit noisy. Output volume can be set at build time using the
VOLUMEparameter. - SPDIF receiver can be used to hear the digital output. Using a 3.5mm-to-RCA cable will output SPDIF audio using what would be the composite video cable. This can be plugged directly into the coaxial input of the receiver.
- Add iCEBreaker target. This can serve as a use case for streaming large audio tracks from flash rather than block RAM.