I want to visit Elgin Park.
Busy with professional work.
Still processing feedback from master.
Met with silicon guru.
Received sample parts.
Thinking about redesign.
More coming soon.
Earlier today, someone I consider to be one of today’s most talented Eurorack designers provided some very insightful feedback on the i8 design over a long and detailed email. Here is a short summary of his main points, ignoring the ones that cannot be addressed without losing the integrity of our approach:
- Deliver 3 to 4 brilliant submodules from day one
- Use RGB knob illumination to help users memorize functions
- Provide more analog ports per channel (ideally 12 or more)
- Use 12V instead of 5V for analog ports
- Get rid of the Arduinos
- Provide better isolation between analog and digital signals
- Use SPI as main digital bus
- Use a single ARM processor to drive everything
- Reduce dependency on any software that could become obsolete
I tend to agree with pretty much everything.
I’m going back to the drawing board.
Eurorack modules use 12V voltage levels, but Arduino’s analog inputs expect 5V. Because of this discrepancy, we will need to use a potential divider along the way. We have two options for it: upstream of the analog port, or downstream. Both options have pros and cons, which are worth reviewing.
If we put the potential divider upstream, we could use standard Arduino shields, but we would need to amplify their outputs to get back to 12V. If we put it downstream, inputs and outputs would remain on a 12V level, but we could not use standard Arduino shields that make use of the analog ports.
Quite frankly, I’m not sure which way to go…