After all that trouble, the (hopefully working) prototype for the board arrived yesterday. It looks great, though work on it will have to wait a bit what with various other things going on in my life. The one exception will, I think, be soldering on some stacking headers and getting it into a stack so it can be tested.
This will be fine for regular Arduino projects, I think, though for the wearable voice changer project that this is supposed to be the core for. I'll probably still work to perfect this, though I think I may also work on dividing the basic audio I/O and the FV-1 processing back into two separate functions, but on sewable boards (rather than the Feather Wings that I started all this with).
There were some issues with the prototype boards, so I had to try a couple more times over the last couple of weeks to correct them. That wouldn't be so bad, even with the time delays, but the extra-fine leads on this board cost an extra $50-60 (over the normal $5).
But the customer service rep and I are now pretty sure that it's working, at least as far as the physical board goes. I just hope the electronics work right this time.
I've finally gotten to where I could purchase the prototype for this board. A whole new estimate was needed; the total I spent was $262, including $5 for an unrelated test board and a $12 bank processing fee. If I get any more, I may see about using a company other then PCBWay; they're wonderful (especially the customer service reps), but the price seems awfully high.
I'm figuring it'll be mid-June before the board arrives. I'd better start getting the other components ready for testing!
After quite a bit of work and component purchasing, I've finally managed to get a combination of screen and board to work together properly. This will be vital for not only the larger project I'm working on this for, but also for controlling and operating the Sound Processing Shield as I work up its sketch library.
The bad news is that I don't really expect to be able to buy my assembled test board until April, or until the COVID relief money comes (whichever is first, though at this rate I'm expecting the latter). So I probably won't be able to do any serious work on this until May... and I'm starting to feel kind of eager to get going!
As of today, I have 91 Followers for this Project. I just thought I'd mention that, since 91 is my favorite number (the explanation of that would be too long to go into here).
On another note, some of you Followers may have noticed a lack of progress here. For one thing, I've had to change apartments -- another long tale, and mostly irrelevant other than how it took up the money I might've spent on the prototype board. For another, the other components I got for my larger voice-changer project -- Arduino board, battery charger, and touchscreen -- are stubbornly not working, and I need them just to test the Sound Processing Shield.
At the end of this month, I'm going to get an alternative for the board, to address a couple of possible issues. That'll take a little while to implement, so it'll be late January at best, and more likely some time in February, before I can send off for the prototype (which of course will take a few weeks to arrive).
It turns out that the prototype board will be more expensive than I'd thought. For some reason the boards had to be upgraded in terms of minimum trace width (even though that hasn't changed since the test boards) to an extra $55 cost, and the components that I thought would cost about $30 are just over $100. In short, the total that I'd expected to be around $70 is instead almost $200.
I can't blame PCBWay, at least for the latter trouble; they're in China (just outside Hong Kong), and importing most of the components.
I'll still get this prototype, but it won't be until December, and if I have these produced in batches I'll probably go to another company.
This afternoon's mail included my sample boards (a batch of 5) from PCBWay, and I'm very happy with their work:
Again, this is a somewhat earlier version of the board; most of the components have been shuffled around, and some have been deleted (and a couple added) since I sent this design. This is mostly to confirm that I got the placement of the Arduino headers correctly -- which, somehow, I did... though I plan to recheck and re-recheck it just to make extra sure.
Now, over the next couple of weeks, I'll be preparing the Gerber and Centroid files for an actual (hopefully) working prototype based on the current layout.
And, by the time that arrives, I hope to have other parts of my larger project working as well.
Besides the typical minor tweaks to the layout, I made a couple of significant adjustments to the board over the weekend. For one thing, I corrected the values of the pull-up resistors from 1M to 10k. I also moved the location of the Clip LED to a spot next to the TRRS plug, where both could be visible from the same end of the enclosure (if any).
Weaving the signal wire for the latter change has me thinking more and more that rotating the FV-1 90 degrees clockwise might be worth the effort after all.
With the opening up of space near the Arduino RX/TX pins, I'm also back to contemplating an I2S interface for this board; I'm just not sure yet how to do it.
It occurred to me just a little while ago that an end user might want to have synchronized lights or some other effect with the voice, so I've connected the mike input at the FV-1 to the one remaining port on the MAX11312. Maybe it should go to one of the speaker output ports; I'm not sure. I may change to that later, especially if someone speaks up.
Also, I removed the extra output connections besides the TRRS jack. Using just one or the other port is a more likely thing for the SPS2. Before I finalize this version of the project, I may bring the right-angle headers back, or put bare-wire terminals in their place.
This is in addition to the rerouting of leads to make wiring more efficient.
I'm also considering a row of connections to allow a user to put in jumpers, connecting the FV-1's input and output directly to the analog I/O -- but not yet.
This morning I ordered the PCBs that I'll be using to make sure all of the headers are aligned correctly. They won't have the components on them (what a waste that'd be if the headers are on wrong!), but they'll get here relatively quickly (2-3 weeks, from China, as opposed to half again that with the components) and enable me to take the next step forward: the prototype!
bobgreenwade
