Beginner questions, extending / mounting the DIY board

[6495202]

Hi, and thank you for your amazing product.

1. In http://gechologic.com/support/index.php?topic=123.0 you mentioned to add a 220mF capacitor in series with an additional external mic - Could you post a photo of what this looks like when soldered on? As for the firmware, you mentioned in a future version the additional mic could be controlled (on, off, mix) - does this alreary exist? If not, how does it currently behave?

2. At http://phonicbloom.com/diy/make_your_own_enclosure/ the SDIO in seems to have 4 connections. Online, I'm finding SDIO slots with 9 or 12 pins. How to solder this, exactly? Is a specific part expected, and if yes, could you point one out at mourse.com or so?

3. If I'm adding the mic and the line-out, can/should I connect both to the same AGND?

Thank you!

[6495202]

Adding some more questions:

- Can the Glo receive or send clock in any way?
- The LED colors do not seem to work correctly for me. For binaural bests or isochronic tones, they do not shine amber, blue, green, turquoise. Usually it's either blue, red, or off. Is this a known issue?
- What's the best approach to attach a dial / knob, that lets the user select any of the 24 channels directly?

[mario]

Hi! Thank you, happy you like it!

What kind of board (or breadboard) are you prototyping on? Not sure how useful for you is to see this as you may need to use different kind of caps, maybe not even SMD.

The caps are commonly placed on mic or line inputs to remove DC voltage and let only AC signal through, I made these experiments on the custom PCB - the last picture here shows the bottom side and the 220nF caps.

Firmware - well I have what is shown in the demo there, if I remember correctly it's a binary compiled to use line-in instead of mics and there was no control to switch it - haven't worked on it since however the code base is shared with Gecho where these options already exist - eventually I will enable them in Glo as well, where they make sense. That will probably happen later this year when I'll get a chance to move on with this model - because eventually I'd like to design a single-PCB pocket synth with touch keyboard like this board uses.

As for SD, you can use any slot you want - signals compatible with Glo board you have are as shown here, however this is not the most fortunate solution as it only works with 1-bit SPI mode, and is slower than what can be achieved with ESP32 if you use full 4-bit SDIO mode. It is good enough to load-store data - patches, configuration, samples to load to memory and play, even to build a mp3 player (ESP32 has enough power for that) but not to read/write wav files at a higher sampling rate.

Mic and line-out (if not wired differentially), yes, same AGND.

[mario]

- Can the Glo receive or send clock in any way?

No, unless you program it in. It can have MIDI so it could send clock there. Or you mean some other hardware sync signal? That would be a nice programming exercise too

- The LED colors do not seem to work correctly for me. For binaural bests or isochronic tones, they do not shine amber, blue, green, turquoise. Usually it's either blue, red, or off. Is this a known issue?

So you never get any colour that consists of green element - maybe the LED is damaged? What do you see on power on? It should quickly cycle through all 3 colours.

- What's the best approach to attach a dial / knob, that lets the user select any of the 24 channels directly?

Like this? I used the I2C encoder, as you saw in this article but even a potentiometer could be used, when wired to some ADC capable input. The firmware does not support this (yet) simply because there was no interest in DIY beyond the "build your own enclosure" and "add charging circuit", you are the first one to ask about this
 

[6495202]

Thank you for your replies.

I haven't started prototyping. Just gauging what I could do that would be on my level, which is zero. I have a box to fit the board in. My plan is to add a some stuff on the outside, like springs or a kalimba. A knob to dial in the channels directly would be my preferred mod.

Diodes: It sounds like I don't have green, then. On startup there is only red and blue flashing, then the switches to purple.

I got the DIY set that came without the expansion board. Do you still sell those?

[mario]

I have a box to fit the board in. My plan is to add a some stuff on the outside, like springs or a kalimba.

Sounds good!

A knob to dial in the channels directly would be my preferred mod.

I can add this to the next firmware version, it's a very simple modification.

Diodes: It sounds like I don't have green, then. On startup there is only red and blue flashing, then the switches to purple.

While I test every board before shipping, things may happen during transport or use - if this bothers you, feel free to ship it back and I'll fix it or replace for new board if it cannot be easily fixed.

I got the DIY set that came without the expansion board. Do you still sell those?

Well I did not officially release that board as it has a small error in it (one resistor needs to be soldered sideways, if you look closely at this picture maybe you will find it - it is marked "100k"). And I did not have time to revise this and order flawless PCBs. You can have one of these experimental boards if you want, maybe it will save you time - and also the question is if it can fit into the box you have and if the keypad is any good for your application at all.

At the moment it does as much as is shown in the demo - plays usual channels and where applicable, sends MIDI notes out. I also wrote a test binary for the touch keyboard to see if/how well it works (and it does reasonably well), but this is not yet integrated in the software - however it is a trivial thing to implement, I just did not have time to do it - but the idea is that notes from the keyboard will be added to the incoming MIDI data stream, and the rest of the software will handle it normally.

[coutlasssupreme]

Hi Mario,

I would love one of these boards. I fount the sideways resistor. I think I can pull it off. Do you still have some?

[mario]

Hi Jorge, I still have them - also panels to make a complete enclosure. But you will need to attach the Glo board permanently and end up with empty wooden Whale case. You could get a bare Glo PCB and assemble another one (there are 0402 components). Also this version is less than ideal because SD card is wired in 1-bit SPI mode which is slow. This board will get redesigned soon, probably accepting standard ESP32-WROVER or ESP32-WROOM modules instead of the Glo board.

[coutlasssupreme]

Mario, I would like the expansion board. My whale is a DIY kit, and id love to add the inputs like this.

Let me know how I can pay it and you could send it with the gecho I'm ordering when they are available.

Jorge

[mario]

Ah that's cool! Just leave a note with Gecho order later, I'll contact you about the expansion board and possibly enclosure panels. Or if you change your mind and want them earlier, let me know.

[coutlasssupreme]

Mario,

Actually, assembling a Glo sounds very fun. Let's arrange for you to send me another bare Glo and the expansion board.

My email is [email redacted by admin to not attract spam] if you want to send some instructions on how to go about it.

Thanks

[mario]

Cool! I'll email you soon.