What's the most difficult and time-consuming task in this project? Coding the sampler software? No. Soldering and assembling all the components together? No. Designing the custom enclosure? No!
The answer is: sourcing the components.
A huge amount of time has been spent on finding the right components: which DAC (digital to analog converter, i.e. the device which converts 0s and 1s into real-life sound!) to choose, etc. ?
But the most difficult task was to find the right component to provide a SD card slot.
It looked simple at first sight:
- Why not use this ultra-classical component "SD card module", available in all online electronic shop?
The answer is simple: to interface this module with the RaspberryPi, we have to use the SPI interface (is there another solution using directly SDIO? If you do know, please let me know), which results in a very low transfer rate limit, around ~ 1.5 MB/sec. Loading a 200 MB instrument on a SamplerBox would require more than 2 minutes!
I've been looking for a solution for weeks, until someone pointed me today to this part:
I cross my fingers until this component arrives, to see if it will work as expected!