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mitchel6
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Coarse tune problem

Post by mitchel6 » Thu May 18, 2017 1:32 pm

Hi.
I built one and have a problem.
The module worked just fine before I cariblate it.
But after cariblation, polarity of the coarse knob have inverted.
Any ideas???

Thanks in advance.

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mwgilbert
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Re: uBraids build error/anomaly

Post by mwgilbert » Thu May 18, 2017 1:56 pm

ZZ Ardoz wrote:I've built a bunch from both version of the pcbs (which one do you have?) and have never had an issue with any of Magpie's boards, which are excellent.

Maybe some high-res photos would help - can you provide some?
Thanks very much.These are all v2. I will post photos tonight.

M. Gilbert

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Re: uBraids build error/anomaly

Post by ZZ Ardoz » Thu May 18, 2017 2:01 pm

mwgilbert wrote:
ZZ Ardoz wrote:I've built a bunch from both version of the pcbs (which one do you have?) and have never had an issue with any of Magpie's boards, which are excellent.

Maybe some high-res photos would help - can you provide some?
Thanks very much.These are all v2. I will post photos tonight.

M. Gilbert
Yeah - not a bad pcb in the batch - or any Magpie board for that matter. If I had to put blind money on it, it would be a bad component.

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Post by Altitude909 » Thu May 18, 2017 2:29 pm

did u have the pot centered when you calibrated?

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Post by mwgilbert » Thu May 18, 2017 2:42 pm

Altitude909 wrote:did u have the pot centered when you calibrated?
I believe so. I will re-calibrate this evening to be sure. Thanks, and I'll post the result.

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Re: uBraids build error/anomaly

Post by GryphonP3 » Thu May 18, 2017 3:24 pm

ZZ Ardoz wrote:
mwgilbert wrote:
ZZ Ardoz wrote:I've built a bunch from both version of the pcbs (which one do you have?) and have never had an issue with any of Magpie's boards, which are excellent.

Maybe some high-res photos would help - can you provide some?
Thanks very much.These are all v2. I will post photos tonight.

M. Gilbert
Yeah - not a bad pcb in the batch - or any Magpie board for that matter. If I had to put blind money on it, it would be a bad component.
That is very strange that some of his output waves are working and some aren't. The circuit does not use different paths for different waveform outputs iirc. Thats stumping me. Different pots not working and all that, I would recommend reflowing opamps and DACs. I cant think of any advice for certain waveforms bot outputting at all. I know some have different relative pitches, and harmonics based on the pot settings, so if the pots are short/open circuit from the op amps, they could come through as very quiet or silent, but that would also impact other waveforms, which would not be working perfectly. I would start by reflowing pots and op amps, anyway, and go from there. Are you sure some waveforms are working "perfectly" Gilbert?
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Post by mitchel6 » Thu May 18, 2017 5:17 pm

Altitude909 wrote:did u have the pot centered when you calibrated?
Hi. Yes I did. Here's a picture.

Picture file

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Re: uBraids build error/anomaly

Post by mwgilbert » Thu May 18, 2017 8:22 pm

GryphonP3 wrote:That is very strange that some of his output waves are working and some aren't. The circuit does not use different paths for different waveform outputs iirc. Thats stumping me. Different pots not working and all that, I would recommend reflowing opamps and DACs. I cant think of any advice for certain waveforms bot outputting at all. I know some have different relative pitches, and harmonics based on the pot settings, so if the pots are short/open circuit from the op amps, they could come through as very quiet or silent, but that would also impact other waveforms, which would not be working perfectly. I would start by reflowing pots and op amps, anyway, and go from there. Are you sure some waveforms are working "perfectly" Gilbert?
We reflowed opamps and DAC/ADC. We also checked control voltages at the inputs of the ADC. Yes, some waveforms are working.

All I have this evening is an iPhone, so this is the best image qual for now. Please excuse flux, etc. from all the extra reflowing. I will get some better images ASAP. Again, this is now just a learning/curiosity project.
Image
Image
Image

If we don't solve this, and I don't think we have the time to start swapping all the passives, we'll chalk it up to experience.

Thanks to all commenters!

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Post by mwgilbert » Thu May 18, 2017 8:24 pm

mwgilbert wrote:
Altitude909 wrote:did u have the pot centered when you calibrated?
I believe so. I will re-calibrate this evening to be sure. Thanks, and I'll post the result.
Apologies to Altitude909, the comment above was not for us. Yes, our module does calibrate and accurately tracks 1v/oct for what it';s worth :)

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Re: uBraids build error/anomaly

Post by GryphonP3 » Thu May 18, 2017 9:34 pm

mwgilbert wrote:
GryphonP3 wrote:That is very strange that some of his output waves are working and some aren't. The circuit does not use different paths for different waveform outputs iirc. Thats stumping me. Different pots not working and all that, I would recommend reflowing opamps and DACs. I cant think of any advice for certain waveforms bot outputting at all. I know some have different relative pitches, and harmonics based on the pot settings, so if the pots are short/open circuit from the op amps, they could come through as very quiet or silent, but that would also impact other waveforms, which would not be working perfectly. I would start by reflowing pots and op amps, anyway, and go from there. Are you sure some waveforms are working "perfectly" Gilbert?
We reflowed opamps and DAC/ADC. We also checked control voltages at the inputs of the ADC. Yes, some waveforms are working.

All I have this evening is an iPhone, so this is the best image qual for now. Please excuse flux, etc. from all the extra reflowing. I will get some better images ASAP. Again, this is now just a learning/curiosity project.
Image
Image
Image

If we don't solve this, and I don't think we have the time to start swapping all the passives, we'll chalk it up to experience.

Thanks to all commenters!
I cant tell from this resolution, but the STM32 looks to have some suspect pins around the bottom left side from the pic viewing angle. I would drown it in flux and gently reflow around that. This chip is usually the culprit when sound functions aren't working, especially if the op amps et all are clean.
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Re: uBraids build error/anomaly

Post by pld » Fri May 19, 2017 2:48 am

mwgilbert wrote:We reflowed opamps and DAC/ADC. We also checked control voltages at the inputs of the ADC. Yes, some waveforms are working.
What's your criteria for "working", i.e. have you looked at the output with a scope? Assuming the signal path is unchanged from the regular Braids, there's a few places to systematically localize the issue (DAC output, pre-/post-filter, AC coupling, output gain) and/or compare behaviour with other waveforms. If you haven't done so, checking the relevant voltages for the output path (+-12V at the 072, DAC 2V5 reference), and looking for changes in either V or signal when output is good/bad would be a first step.

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Re: Coarse tune problem

Post by pld » Fri May 19, 2017 2:56 am

mitchel6 wrote:Hi.
I built one and have a problem.
The module worked just fine before I cariblate it.
But after cariblation, polarity of the coarse knob have inverted.
Any ideas???

Thanks in advance.
What's the voltage source for calibration, or better: have you measured the 1V/3V you were using to calibrate?

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mwgilbert
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Re: uBraids build error/anomaly

Post by mwgilbert » Fri May 19, 2017 8:20 am

GryphonP3 wrote:I cant tell from this resolution, but the STM32 looks to have some suspect pins around the bottom left side from the pic viewing angle. I would drown it in flux and gently reflow around that. This chip is usually the culprit when sound functions aren't working, especially if the op amps et all are clean.
Thanks! We have another build session this weekend and will do that. I will also post a real image after that.
pld wrote:What's your criteria for "working", i.e. have you looked at the output with a scope? Assuming the signal path is unchanged from the regular Braids, there's a few places to systematically localize the issue (DAC output, pre-/post-filter, AC coupling, output gain) and/or compare behaviour with other waveforms. If you haven't done so, checking the relevant voltages for the output path (+-12V at the 072, DAC 2V5 reference), and looking for changes in either V or signal when output is good/bad would be a first step.
Thanks! Yes, we looked at the output with a scope.
We did check all supply voltages everywhere, but will check for V changes between settings. The signal when output is bad is nil.

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Re: uBraids build error/anomaly

Post by pld » Fri May 19, 2017 9:53 am

mwgilbert wrote:Thanks! Yes, we looked at the output with a scope.
We did check all supply voltages everywhere, but will check for V changes between settings. The signal when output is bad is nil.
Well I'm a measure/localize-first kind of guy, so I'd check the signal at the DAC. If it's also nil, then a likely cause are the SPI lines and maybe some mechanical stress using the encoder is enough to cause intermittent faults. Coincidentally I think they're the bottom side, left-most pins on the stm32 as GryphonP3 suggests, so a reflow-first approach may well things working quicker :)

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Re: Coarse tune problem

Post by mitchel6 » Sun May 21, 2017 4:40 am

pld wrote:
mitchel6 wrote:Hi.
I built one and have a problem.
The module worked just fine before I cariblate it.
But after cariblation, polarity of the coarse knob have inverted.
Any ideas???

Thanks in advance.
What's the voltage source for calibration, or better: have you measured the 1V/3V you were using to calibrate?
The voltage source is a References App of O_c.
And yes, I measured the 1V/3V by DMM.

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Post by GryphonP3 » Mon May 22, 2017 12:46 am

Here's a weird one:

I have built about 20 of these so far, always able to get them up to 100%, then on this most recent batch, I had this identical problem on 2 modules:

Image

Little line to the left. All of the pins on the associated chips are perfect. The only thing that has changed from my normal process is that my screens were from a newer adafruit order than my old stock. Maybe a coincidence though? If so, has anyone seen this problem and dealt with it before? I've troubleshot all usual display culprits over and over to no avail.
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Post by pld » Mon May 22, 2017 12:56 am

GryphonP3 wrote:Little line to the left. All of the pins on the associated chips are perfect. The only thing that has changed is that my screens were from a newer adafruit order than my old stock. Maybe a coincidence though? If so, has anyone seen this problem and dealt with it before? I've troubleshot all usual display culprits over and over to no avail.
Could be a SH1106 vs. SSD1306 (the OLED driver) disparity; they are mostly compatible except for a minimally different memory layouts (IIRC 128x64 vs 132x64, so off by 4px). Depending on the graphics library used you might be able to change the type or offset to compensate.

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Re: Coarse tune problem

Post by pld » Mon May 22, 2017 1:03 am

mitchel6 wrote:The voltage source is a References App of O_c.
And yes, I measured the 1V/3V by DMM.
Calibration went wrong using an o_C? Inconceivable :D
Hm, incorrect voltages and/or knob positions are the obvious things. Does the v/oct input work properly?

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Post by GryphonP3 » Mon May 22, 2017 1:38 am

pld wrote:
GryphonP3 wrote:Little line to the left. All of the pins on the associated chips are perfect. The only thing that has changed is that my screens were from a newer adafruit order than my old stock. Maybe a coincidence though? If so, has anyone seen this problem and dealt with it before? I've troubleshot all usual display culprits over and over to no avail.
Could be a SH1106 vs. SSD1306 (the OLED driver) disparity; they are mostly compatible except for a minimally different memory layouts (IIRC 128x64 vs 132x64, so off by 4px). Depending on the graphics library used you might be able to change the type or offset to compensate.
Will check tomorrow - left my studio for the night. I have 3 more on the workbench ready to do the hardqare as well so we will see if the problem persists with those. Thanks for the reply!
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Post by Altitude909 » Mon May 22, 2017 5:17 am

GryphonP3 wrote:Here's a weird one:

I have built about 20 of these so far, always able to get them up to 100%, then on this most recent batch, I had this identical problem on 2 modules:
..
Little line to the left. All of the pins on the associated chips are perfect. The only thing that has changed from my normal process is that my screens were from a newer adafruit order than my old stock. Maybe a coincidence though? If so, has anyone seen this problem and dealt with it before? I've troubleshot all usual display culprits over and over to no avail.
That's a faulty display. Got one from adafruit myself, they should replace it. It's why I make my own screens now. You would think that for what they charge, there would be better QC. I looked at the bad one I had under a miciroscope and the solder paste they used to solder the flexboard was not even remotely close to being gone, no doubt shorting adjacent pins

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Re: Coarse tune problem

Post by mitchel6 » Mon May 22, 2017 6:40 am

pld wrote:
mitchel6 wrote:The voltage source is a References App of O_c.
And yes, I measured the 1V/3V by DMM.
Calibration went wrong using an o_C? Inconceivable :D
Hm, incorrect voltages and/or knob positions are the obvious things. Does the v/oct input work properly?
Inconceivable yes. I also checked ICs and passives around it.
V/OCT input is working properly..

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Post by GryphonP3 » Mon May 22, 2017 9:31 am

Altitude909 wrote:
GryphonP3 wrote:Here's a weird one:

I have built about 20 of these so far, always able to get them up to 100%, then on this most recent batch, I had this identical problem on 2 modules:
..
Little line to the left. All of the pins on the associated chips are perfect. The only thing that has changed from my normal process is that my screens were from a newer adafruit order than my old stock. Maybe a coincidence though? If so, has anyone seen this problem and dealt with it before? I've troubleshot all usual display culprits over and over to no avail.
That's a faulty display. Got one from adafruit myself, they should replace it. It's why I make my own screens now. You would think that for what they charge, there would be better QC. I looked at the bad one I had under a miciroscope and the solder paste they used to solder the flexboard was not even remotely close to being gone, no doubt shorting adjacent pins
Thanks for letting me know before I pulled my hair out even more troubleshooting. Two in one batch!! Thats terrible. I will give them a shout tonight.
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Post by Altitude909 » Mon May 22, 2017 10:07 am

Does it flicker? Maybe it's bad parts and not a process thing.. I replaced the bad display with a eastrising part and it worked fine

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Post by ZZ Ardoz » Mon May 22, 2017 1:27 pm

Altitude909 wrote:
GryphonP3 wrote:Here's a weird one:

I have built about 20 of these so far, always able to get them up to 100%, then on this most recent batch, I had this identical problem on 2 modules:
..
Little line to the left. All of the pins on the associated chips are perfect. The only thing that has changed from my normal process is that my screens were from a newer adafruit order than my old stock. Maybe a coincidence though? If so, has anyone seen this problem and dealt with it before? I've troubleshot all usual display culprits over and over to no avail.
That's a faulty display. Got one from adafruit myself, they should replace it. It's why I make my own screens now. You would think that for what they charge, there would be better QC. I looked at the bad one I had under a miciroscope and the solder paste they used to solder the flexboard was not even remotely close to being gone, no doubt shorting adjacent pins
I had 2 bad ones in the last lot. And quite a few where the screen itself was really not put on straight enough to qualify as a good job. a bit disappoiniting. Will be making my own ones after this as well.

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Post by GryphonP3 » Tue May 23, 2017 12:24 am

Altitude909 wrote:Does it flicker? Maybe it's bad parts and not a process thing.. I replaced the bad display with a eastrising part and it worked fine
It didn't flicker, no. I sold one with this issue to a customer at a discount a week or two ago who wanted one without waiting for a new batch and didn't mind the line. He said the screen went totally dead after being on for a few hours straight. Now I have to replace it with a new one for him, at Adafruit's fault. On these ones in this batch, I swapped both faulty displays out for others which work perfectly. So the displays were definitely at fault all three with identical issues. Weird!! Cant believe this level of QC. I hope they dont make me jump through hoops over there for replacements. When I sent a support message informing them of the problem they said I need to address the issie in the forums and get approved by a moderator for replacement. Sounds promising :deadbanana: Eastrising? Are those te blue displays you are using now?
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