06/10/2020 at 15:09 •
I was advised recently that I2C is not a good way to pass audio around, and that I should use I2S instead.
However, after much struggling and researching, I've been unable to figure out how to use I2S as a bidirectional multi-slave bus for audio. Maybe it can be done, and maybe it can't; I'm just not able to figure it out.
I've thus decided to set this project aside and turn my attention to an Arduino Shield that combines this with the AudioWing. That will bypass the need for I2S, taking the processor out of the audio flow altogether and leaving it to control the effects and other functions.
I'll supply a link in a separate log here once I've started that project here on Hackaday.
03/03/2020 at 01:55 •
I've now replaced the TFT capacitors on the design with surface-mount equivalents, and tightened up the copper just a wee bit more. Electronically it's the same, of course, but it's a more efficient design.\
(Keeping copper traces as short as possible both saves on copper, and minimizes the electrical resistance between components. The amount of either is tiny and the amount saved is minuscule, but these things do add up.)
01/17/2020 at 00:35 •
As planned, I've rearranged the connections between the MAX11312 and the FV-1, and I do think that this is an improvement. It did, of course, require some shuffling of pin connections, and I'm not sure that I ended up with fewer vias, but I'm pretty sure this at least uses less copper.
(I've left the jpg of the board layout in the Gallery for comparison. The new one has the name vertically; the old one has it horizontally.)
I'm still a bit uncertain about those pull-up resistors, though (as noted in my previous Log Entry). Whether to remove them, leave them be, or put in a switch or a couple of solder headers, I don't know. For now, I'll leave them.
I think I'm done with major revisions, though, at least until I have a good, working SoundWing.
01/12/2020 at 20:02 •
After finding that I'd neglected to include pull-up resistors on the SoundWing, I decided to check this board as well. Sure enough, no pull-ups were on board.
While probably electronically sound, this layout is a horrible mess of leads and vias, and I think it can be better. I probably will rework the whole thing (including changing the order of I/O connections between the two big chips) before I send this off to anyone.
EDIT: How much do you folks think this board will need pull-up resistors, anyway? This board is intended for use with a SoundWing (another project of mine), which will have them on board; I really can't think of any application that would happen without it. Some feedback on this question would be helpful.
01/03/2020 at 20:59 •
Contrary to my earlier assumption, I found a multi-mode I2C chip with 12 ports: the Maxim MAX11312. I've removed the two that I had been using, along with as many references to them as I could find in the Description, and have put in the MAX11312, with a start at the pin connections. I'd be surprised if I don't have to make some changes in that regard (connecting some floating pins, adding some components, changing a connection or two, etc.), but what I have here will do until I can really dive into the data sheet.
I think the board will be much easier to handle with just one I2C address to worry about.