0voters
Assuming we keep everything else in the design roughly the same, and ignoring implementation difficulty, which of these is best? Let's evaluate these assuming a base board alone without any expansions.
The prototype is Dual Micro-B. Dual C is the easiest revision to make. C and A Host or Micro-B and A Host are about equally tough but not impossible; they'd push the board dimensions up to about 110x45 from 100x40.
Looks like Micro-B + A Host is winning. I'm on board with doing an A host port, but I'm thinking if we do that it will be worth it to upgrade to C for the power/data port. That gives us a more robust connector and a bit more future proofing.
Are you guys picking Micro-B + A just because it's comfortable and the same as the original core? What's the downside to C over Micro-B? Just not enough widespread adoption yet? Is the feeling that C would be annoying just because everyone already has so much Micro-B stuff lying around?
I have had more experience of failure with Micro-B than any other connector, it's not how I voted but maybe the reason the others voted for B and A Host is continuity like you say, I think your suggestion of an A with a C is the best of both worlds
I'm with you here. I'm starting to think that in a couple of years we will end up regretting sticking with Micro-B. Just the pleasing symmetrical quality of C alone is really nice to have. That endless fiddling with Micro-B needs to go away.
FWIW, I was pretty disappointed that the original board had a micro-B connector. I mean, I only got mine earlier this year. But I'm of the opinion that the micro-B connector sucks and is dead dead dead. It's totally supplanted by USB-C, which is much more robust. I actually thought a full-size B made way more sense on the original board, since that is standard for music equipment and there are plenty of big ports on the original board... there was no need to go micro. Also, my MIDI instrument uses full-B, so I'd have consistency through my setup. Micro-B is for [old] cell phones.
It looks like dual-C is winning again.
I personally think the micro usb should go away. I had many problems with the cable getting broke, loose connections, and even one axoloti board where the connector went completetly fucked and bent off.
The host should be either A or C, my first instinct was A since that is the format I have around with all my midi/usb devices, but as mentioned here it seems C will be the main standart in the future and it is more in the spirit of a mini device. What I am wondering about this is though: All these USB hubs with a C connector are USB3.0. It seems out of this discussion that this is not supported, right?
it looks good, very mini! May I ask why there is four mini jacks?
Considering the shield buisiness: I just stumbled on this from the teensy world, good example in how an axoloti shield could look like, right?
https://www.pjrc.com/tga-pro-guitar-audio-shield/
@Blindsmyth See my diagram earlier in the thread. It gives us the possibility of doing four mono balanced channels, i.e. input left and right and output left and right. By default it will work like the old core: stereo in, stereo out, headphone out but with one additional stereo aux in. Each jack can be independently switched from this default setting into the balanced mode.
The reason why I chose Micro-B + A is because if I understood comments about the prototype design, it was with Micro-B+A, and that USB-C is almost a drop in replacement, so this would mean it could start with whats common, and it would be almost a drop in to transfer from micro-B to USB C.
If going straight to USB C is a better option then this shouldn't be ignored.
Hi!
I just recently discovered axoloti, am really interested in this project and looking forward to buy the next generation.
Just created an account to let you know that I would prefer dual C because i hope to get rid of micro rather sooner than later.
Thanks for the effort that is put into this!
Thanks for the feedback everyone. I think there's a pretty clear consensus here about at least abandoning micro-B; I agree. All other things being equal, and ignoring development effort, is there a specific reason you prefer dual C over C + A Host? The robustness and convenience of the full A Host jack seems desirable to me; it's slightly more plug and play with available Midi controllers. But we can do a slightly smaller board with Dual C. To be clear, from a functional perspective they'll operate similarly with our system; the hardware provides USB 2.0 support. It really comes down to feel and convenience.
The compactness and uniformity of having them be both C is nice. Potentially the same cable for both ports. But everyone likely already has tons of A -> B and A -> Micro-B cables for controllers lying around.
100x40 vs 110x48. It's actually about a 25% increase in area but still slightly smaller than the main section of the original core.
for me size is the only factor really. if they would be of equal size i would go for a fullsize a port
That is super great, so it means the configuration of the ports could be switched in like a config object?
Balanced IO onboard would be great! What does aux in mean? does it mean you can have another input that is summed together with the main in?
I have been using the current axoloti with a SM58 and the gain set high also quite a lot but I have to say the audio quality was not really great. So in the end a dedicated shield is the best. But for trying out while patching it was sufficient. And maybe your balanced in will have better quality.
I also think that small size is the main point of this project.
What I find another argument A though is that all these USB C hubs are 3.0, and thus not usable with axoloti.
USB 2.0 hubs often have a cable with USB A connector attached to it.
But the more I think about I come to point that a USB Hub shield would propably very cool. Then we could have C here for small size, and all of us USB controller freaks would want to have more that one port anyway.
Would something like that be possible?
https://www.electrodragon.com/product/usb-battery-power-bank-usb-hub-shield-for-raspberry-pi/
@Blindsmyth Exactly! The IO configuration will be switchable with a config object. We're still dealing with a stereo ADC so when enabled the aux input gets summed in before conversion and has its own programmable gain. Here's what the input stage looks like:
I think this will still be a useful thing to take advantage of though. It's available in the codec; we might as well make it available.
I want to chime in on the USB discussion from above: the microcontrollers on both Axoloti Core and the new Akso board only support USB 2.0. So even with a USB-C physical connector, we'll still be running USB 2.0. Devices that support newer USB standards handle this situation, e.g. a USB-C 3.0 hub will still work.
It's kind of a subtle point: there are physical connectors (A, B, micro-B, C, etc.) and protocol versions (2.0, 3.0, 3.1, etc.). There isn't a clear mapping between the two sets; you can have various protocol versions running on various connectors depending on hardware/software configuration.
