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Post by dizzeesatchel on Aug 29, 2022 8:45:44 GMT
I think the biggest problem is it introduces noise into other modules in the chain. I’ve been doing a bit of rearranging & re-soldering and the back voltage has dropped quite a bit, it’s now only about 1v when connected by usb. I’d like to understand how to get it down to zero but this module wouldn’t be connected to usb while it’s in the case anyway so i’m not too worried. I found this while searching which might be helpful: reddit.com/r/raspberrypipico/comments/wwghgc/can_i_power_the_pico_from_vsys_and_also_have_usb/I fixed the buttons, had them in the wrong orientation…. whoops  Got some different ones for v2 build, lower profile and a bit more clicky, they take a bit more space on the board though so will have to plan around that. Need to check the pots as they’re not quite right, also the digital input (might just be a bad connection there, it’s a real bodge) and figure out how to calibrate the analogue for 5v. Basically i got everything just a little bit wrong  Also somehow i got one of the outputs out of order (i thought i was so careful about those!) The biggest thing is still coming up with a sensible layout for all the connections under the hood so the two boards will slot together neatly. BUT last night was a breakthrough, first time it (almost completely) worked when sandwiched together, buttons working, lots of blinking lights and voltages coming from the outputs all in 0-5v range. Encouraging! Currently awaiting some new perfboard which *claims* to be the exact height & width of a 2U module, so hopefully v2 will be something i can actually mount and test in the rack  |
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Post by keurslagerkurt on Aug 30, 2022 10:04:36 GMT
Impressive sandwich-work dizzeesatchel! By the way, if anyone ever wants to do a run of PCB's for this, feel free to use my schematics. (In case anyone would want to do a bigger run, its of course best to contact Allen Synthesis from EuroPi who I based the schematics of, he's a superhelpful and kind person, so I'm sure it would work out). I was thinking about doing it myself, but my attention has shifted a bit away from DIY AE this summer (more work, more shows, and more aperitifs with the hot weather  ). So really happy to see that my small experiments can mean something to other users! On your issues, I'm not sure what their causes are, but my bet would be its soldering/layout on the protoboard. It's why I stopped with using protoboard, I'm too sloppy with it and it always takes a long long time to debug the board (longer than it takes to design a PCB layout..). The +2V flowing back def seems like something with the circuit. No diode will leak voltage back like that AFAIK. |
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Post by dizzeesatchel on Aug 30, 2022 11:23:09 GMT
Yeah i've made a number of revisions to this prototype going back and forth so i'm sure its my layers of duff soldering to blame.
But i learned a lot laying it out like this and when the slightly larger (hopefully!!) protoboard arrives there'll be a tiny bit more room to play with so should be able to make the layout more efficient. The board i was using here has these pre-flowed connections arranged in columns, which i thought would be super useful for sharing signals, as it's similar to working on a breadboard, but i think it's more hassle than its worth tbh and probably the cause of some of the problems encountered.
I'm pretty sure the pots acting up are because i did a bad job cutting the traces between each pin, should be fine to solve in v2.
Digital input is fine on further testing, just need to get smarter about transferring the connection from one layer to the other.
Only just noticed the europi pinout diagram in the github and that explains why my outputs were in the wrong order (wonder why they did it like this?):
I'm still a bit flummoxed about the analogue in... The Europi schematic has a pretty complex input borrowed from MI
keurslagerkurt for simplicity's sake i was just going with a single CV input rather than following your plan of a switchable CV in / assignable by pots input. It looks like on your diagram the input just goes directly into the Pico GP26 through a 47k resistor? I guess it needs to be pulled to ground at some point but not sure physically where to put a GND connection in that chain? With nothing connected - using the diagnostics.py script, my analogue in is flipping between 0 - 5v wildly. Probably because its not pulled to ground? But when connecting an input it isn't read accurately either.
Also, and this might be one to ask Rory rather than here, but the calibration procedure asks for a 10v signal input. I'm assuming we could simply give it 5v at that point to correctly calibrate for AE-land?
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Post by dizzeesatchel on Aug 30, 2022 13:31:37 GMT
Perfect! Obviously mounting holes aren't quite in the right place, but will worry about that later.
edit: i got this off eBay if anyone is looking for something similar |
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Post by reductionist_earth_catalog on Aug 30, 2022 20:39:53 GMT
That looks really nice! Would be interested in buying some of those protoboards as well
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rappel
Junior Member
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Post by rappel on Sept 5, 2022 13:09:02 GMT
I like the Pico can have a small screen. Euro Pi does not have any. I've not yet written any video code for the Pi, but a visualizator 8 bit 256 colors module with video output and X and Y corrections, would be gruesome! Ok, that might take quite some time It would be easier to upload a retropi , load a demo, and pretend it's doing some kind of magic!! |
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Post by dizzeesatchel on Sept 7, 2022 18:14:04 GMT
sneak peek. still a few things to fix, but at least it fits!
edit: oops just killed that Pico i think. Hopefully all the other bits are ok and i can just swap in a new one.
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Post by dizzeesatchel on Sept 7, 2022 19:16:16 GMT
I like the Pico can have a small screen. Euro Pi does not have any. I've not yet written any video code for the Pi, but a visualizator 8 bit 256 colors module with video output and X and Y corrections, would be gruesome! I was thinking about video synths recently, really interesting field, something like that for AE would be, uh, pretty niche, but cool! Quantum VJ is nice but the design and software doesn’t seem to be open source, otherwise it would be ideal for some kind of adaptation i think Longer-term, i would love to do something in the field of livecoding with the europi, i found some guides to a way to mirror the Micropython repl on the OLED, haven’t got it working yet though. Even better would be connecting a keyboard directly to the module a la Monome Teletype, but i can’t figure out if that’s even possible with a pico…maybe with the newer wifi version? |
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Post by keurslagerkurt on Sept 23, 2022 7:03:16 GMT
Yeah i've made a number of revisions to this prototype going back and forth so i'm sure its my layers of duff soldering to blame.
But i learned a lot laying it out like this and when the slightly larger (hopefully!!) protoboard arrives there'll be a tiny bit more room to play with so should be able to make the layout more efficient. The board i was using here has these pre-flowed connections arranged in columns, which i thought would be super useful for sharing signals, as it's similar to working on a breadboard, but i think it's more hassle than its worth tbh and probably the cause of some of the problems encountered.
I'm pretty sure the pots acting up are because i did a bad job cutting the traces between each pin, should be fine to solve in v2.
Digital input is fine on further testing, just need to get smarter about transferring the connection from one layer to the other.
Only just noticed the europi pinout diagram in the github and that explains why my outputs were in the wrong order (wonder why they did it like this?):
I'm still a bit flummoxed about the analogue in... The Europi schematic has a pretty complex input borrowed from MI
keurslagerkurt for simplicity's sake i was just going with a single CV input rather than following your plan of a switchable CV in / assignable by pots input. It looks like on your diagram the input just goes directly into the Pico GP26 through a 47k resistor? I guess it needs to be pulled to ground at some point but not sure physically where to put a GND connection in that chain? With nothing connected - using the diagnostics.py script, my analogue in is flipping between 0 - 5v wildly. Probably because its not pulled to ground? But when connecting an input it isn't read accurately either.
Also, and this might be one to ask Rory rather than here, but the calibration procedure asks for a 10v signal input. I'm assuming we could simply give it 5v at that point to correctly calibrate for AE-land?
Usually I get an e-mail to notify me when I get tagged, but I apt missed it.. So, sorry for my late answer! The 47k + potentiometer at the input stage are a voltage divider. If you turn the pot all the way to one side, you will get a voltage divider from 5V -> 3.3V. Turning the pot in the other direction attenuates it further. It's an easier input stage than the Eurorack version because we have less things to worry about. We are SURE that there will be no voltages outside the 0-5V range, where Eurorack has a much wider range of possible voltages depending on different modules. I myself had no troubles with a flipping voltage, also, if the pot is turned to 'full attenuation', the input should essentially be connected to ground. I remember I contacted Rory for the calibration, i did use 0-5V inputs from my 2ATT module to calibrate, checked with a voltmeter. I'm not sure if I had to change anything in the python calibration script to be honest.. But I remember Rory was very helpful! |
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frndo
Full Member
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Post by frndo on Nov 23, 2022 17:47:45 GMT
Hi to All! pump this post, to make a quick (from a begginer) question. I tried the last days breadboard the Pi Pico with euroPi firmware. I upload all the libraries, and scripts; but still fail to work (the error message indicates that the OLED it´s no connected). Any idea? I tried the OLED with arduino and works well, and use the Pico Board with a sequencer firmware, and works to! Maybe I lost in some point of the github schematic. Thanks for your help!
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Post by dizzeesatchel on Nov 23, 2022 20:12:31 GMT
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frndo
Full Member
Posts: 110
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Post by frndo on Nov 23, 2022 20:54:44 GMT
Thanks for answering! Yeah, I doubled check the OLED specs, before purchase; and it´s a model describes in github. dizzeesatchel Do you think that swap pins (ex. SCL - SDA) maybe works? I would be happy, that it works even without the OLED (as it happened with version 1 of EuroPi); I even thought about commenting on the code, everything related to the screen; but I see that in this version there is a whole interface and a menu that is executed from the OLED. |
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Post by dizzeesatchel on Nov 24, 2022 10:27:56 GMT
I would definitely check the layout of pins on the OLED - they should be labelled on the underside of the screen (they are on mine) - double check each one is going to the right place. It does sound like that's the problem if you get the no OLED error. Also check any libraries for the screen are installed. I really want to get mine working but i blew up my Pico and got discouraged for a while |
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frndo
Full Member
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Post by frndo on Dec 3, 2022 15:44:58 GMT
Hi! I'm sorry for the delay. It is definitely something related to the order of the OLED pins, I have the CPC version. I see that in the assembly instructions there are two types of configurations, but I don't understand how that is transferred to the breadboard or if I have to specify something in the code? I already tried changing the pins in the code and it tells me that the SCL PIN is incorrect. Thanks a lot for your advices, and I'm sorry to hear that your Pico blow up! maybe keurslagerkurt knows something about the code? |
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Post by keurslagerkurt on Dec 6, 2022 9:51:57 GMT
Hey frndo ! To be honest, I know next to nothing about communication protocols (SPI, I2C,..) between peripherals like OLEDs and the Pico board. If I recall correctly, I connected the OLED according to a schematic that came with the OLED itself and the pinout of the Pi Pico. I didn't change anything in the code for that, because the code should be the same for communicating between the OLED & the Pico, it shouldn't matter whether it is meant for Eurorack, AE,.. Regarding calibration etc, I think I messed in the setup code a little bit, but that was a long time ago.. Most importantly, I got help from Rory of the EuroPi project himself. I sent him a message on Reddit, and he was very kind & fast to answer, a supernice person. I read that by now, the calibration process etc might have changed also a bit in the code, so I think it is def a good idea to contact him if you have any troubles. |
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frndo
Full Member
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Post by frndo on Dec 6, 2022 17:31:24 GMT
Hey frndo ! To be honest, I know next to nothing about communication protocols (SPI, I2C,..) between peripherals like OLEDs and the Pico board. If I recall correctly, I connected the OLED according to a schematic that came with the OLED itself and the pinout of the Pi Pico. I didn't change anything in the code for that, because the code should be the same for communicating between the OLED & the Pico, it shouldn't matter whether it is meant for Eurorack, AE,.. Regarding calibration etc, I think I messed in the setup code a little bit, but that was a long time ago.. Most importantly, I got help from Rory of the EuroPi project himself. I sent him a message on Reddit, and he was very kind & fast to answer, a supernice person. I read that by now, the calibration process etc might have changed also a bit in the code, so I think it is def a good idea to contact him if you have any troubles. Hi! thanks for answering! I was finally able to get it working!!. It seems something very basic, but for a beginner, it was not easy to figure out... the CPC model of OLED, needs the connection to the Pi Pico of SCL and SDA; and you also need the SCL and SDA connection to the I2C pins. I'll keep putting it together and contact Rory if I can't get the calibration right (it's a long term project and I'm going slowly). |
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Post by waporwave on Dec 20, 2022 7:10:50 GMT
Oh cool, I'd definitely be down to test, I love programming DSP stuff. Didya give the 3 out already or have they not been made? Weirdly when I checked this micro controller out though, it said only 1 purchase per customer... must have just been that one seller, I kind of just assumed that they were in short supply all around.
I was actually thinking about doing this myself, but hooking it up in a different way, for what I would want to do, but I'm waiting on some other things.
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Post by keurslagerkurt on Dec 23, 2022 15:50:36 GMT
Oh cool, I'd definitely be down to test, I love programming DSP stuff. Didya give the 3 out already or have they not been made? Weirdly when I checked this micro controller out though, it said only 1 purchase per customer... must have just been that one seller, I kind of just assumed that they were in short supply all around. I was actually thinking about doing this myself, but hooking it up in a different way, for what I would want to do, but I'm waiting on some other things. Heyo, the prototype never made it off the breadboard! Got sidetracked by a lot of other stuff going on, and also the end of the covid era meant spending more time outside again. (so less time in the synthesizer bunker). If anyone wants to use the schematics to make a proper PCB prototype, feel free! It needs some clever thinking to integrate the Pi Pico into/onto the PCB. Or it is also possible to work with the RP2040 directly, but then you will also need some extra stuff detailed in the datasheet (timer crystal, some caps/resistors,..) |
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Post by waporwave on Dec 24, 2022 2:51:17 GMT
Oh cool, I'd definitely be down to test, I love programming DSP stuff. Didya give the 3 out already or have they not been made? Weirdly when I checked this micro controller out though, it said only 1 purchase per customer... must have just been that one seller, I kind of just assumed that they were in short supply all around. I was actually thinking about doing this myself, but hooking it up in a different way, for what I would want to do, but I'm waiting on some other things. Heyo, the prototype never made it off the breadboard! Got sidetracked by a lot of other stuff going on, and also the end of the covid era meant spending more time outside again. (so less time in the synthesizer bunker). If anyone wants to use the schematics to make a proper PCB prototype, feel free! It needs some clever thinking to integrate the Pi Pico into/onto the PCB. Or it is also possible to work with the RP2040 directly, but then you will also need some extra stuff detailed in the datasheet (timer crystal, some caps/resistors,..) yeah send em so people can see, what exactly are these schematics that you're referring to for though?
I'm planning on doing more DIY soon, and using that raspi thing was on my list. it was 3.3v iirc, so you would just need to adjust inputs and outputs?
Edit: OH, I thought I was on a different thread and got confused, sorry. I see. Also, I don't think using the chip directly is that much of a benefit since the price is so low anyways.
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Post by dizzeesatchel on Feb 13, 2023 13:00:24 GMT
I had a few month's break from this but i do really want to finish it! Think i'm best off starting the whole thing from scratch at this point, happily i think there's enough of all the major components left (might have to top up on resistors). The most frustrating thing is not being able to find double-sided prototype board in the appropriate size!  Closest i've found is this one but the mounting holes are very weirdly located... |
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Post by waporwave on Feb 16, 2023 7:28:53 GMT
I'm also working on my project slowly. I had similar issues with finding a good prototype board, cut up some cheap ones, but they were a pain to work with, and only single sided. I've just gone back to all breadboard for now.
Another thing I wanted to mention is the Digital Out, which is not included in the original schematic pic. Using tons of Op amps is a waste, and the equivalent transistor circuit seems to be pretty big. What I'm using right now is an inverter chip that I had lying around, which will accept my 0-3.3v and invert to 5-0v, and I have all my logic inverted in code. I think there's also voltage stepper ICs which I might look into? Only problem right now is that the inverter rise time is actually like 1/20th the speed of my DACs max, which is not a big problem for cv, but I want to try audio output aswell and I don't know if it would be fast enough.
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Post by dizzeesatchel on Feb 16, 2023 13:14:41 GMT
might just bodge the lack of double-sided board like so.... (there's only a few things which need to go on 'upside-down')
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Post by dizzeesatchel on Feb 18, 2023 23:26:55 GMT
Third time lucky??  Having a little double-sided PCB left over from the DIY kit module turned out to be super useful!
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Post by rodney on Feb 19, 2023 5:40:57 GMT
I'm just catching up with this thread. wow! impressed with both inventiveness and tenacity happening here. ❤
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Post by dizzeesatchel on Feb 19, 2023 17:23:19 GMT
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Got some different ones for v2 build, lower profile and a bit more clicky, they take a bit more space on the board though so will have to plan around that.
Also somehow i got one of the outputs out of order (i thought i was so careful about those!)
). So really happy to see that my small experiments can mean something to other users!
