Raspberry Pi Pico 2 - hands on with audio application - ported Organ and FM synthesizer from ESP32

[@adrimathlener8008]

Wow, love it. And the distortion gives the organ sound it charm.

[@marcellicence]

Thank you. I've added pedal control with a high range of gain to allow internal distortion =)

[@DanielMiclos]

When I saw the news about the Pico 2, your videos were the first thing that came to my mind!

[@marcellicence]

It is indeed an interesting microcontroller board.

[@StepDub]

Nice. Great results for such an inexpensive chip.

[@marcellicence]

Thank you for your feedback =)

[@simbasimba2029]

Jeez, you don't waste any time! Nice work.

[@marcellicence]

Thank you very much. First time that I pre-ordered a product and started quickly to test it out 😀

[@KeyhanAkbarzadeh]

synth sounds great👌🤘and you play really cool! 🤘 thanks for the demo! this is the first thing I'm gonna do when my picos get delivered next week! :D

[@marcellicence]

Thank you very much. I tried out some projects in Arduino in the meantime and they should work =)

[@빛날휘-e8u]

nice demo!!😊😊😊

[@marcellicence]

Thank you =)

[@MagnusWedmark]

Cool video, thanks! Original Pi Pico can normally be overclocked to around 250-270Mhz without upping voltage or anything. Have you tried this? I'm guessing this guy will go higher like 150 => 350 Mhz. And I did some test with one of my PiPicos when it comes to advancing the ADC possiblities on the PiPico and manage, with overvoltage, to get 380Mhz with stable serial traffic. But that is close to the limit. At start speed it seems to read ADC at around 2Msps/12-bits.

[@marcellicence]

Thank you. I've never tried overclocking yet. Reliability stands at the first place in my projects. That would be very nice to use such a high clock rate. Sounds not bad. Do you even get stable ADC readings? I just remember the ADC on the ESP32 which returns more or less unstable values

[@MagnusWedmark]

@@marcellicence pi pico adc's seem much better. I've read an article about the internal capacitors not being optimally chosen, but I think that was more like details. Sorry to say, I don't have reference signals good enough to actually measure how good it is.

[@dubra74]

but I didn't find any schematic how you connected all electronic components 6N138 and raspberry pico 2 pinouts? I uploaded code but can't hear anything ...

[@marcellicence]

I would suggest to have a discussion on GitHub. I am sure we will get it running soon.

[@hastyman]

Do you have any documentation available on how you did this? I placed an order for a Pico 2 the day I saw this video. They were on backorder and it just arrived last night. I'd love to finally get that organ sketch working on something.

[@marcellicence]

This video was made using the Pico SDK. It seems that it results in a better performance than using Arduino. But in the meantime I tested out some of the ml_... projects and got them to work on the Pico 2. I need to prepare the audio driver on GitHub as a final missing piece. I can prepare an update as soon this will work.

[@marcellicence]

I've uploaded an optimized audio driver some minutes ago. Please let me know if you are facing some issues. Pin settings are described in librp2350_i2s_audio.h

[@hastyman]

@@marcellicence this is the most optimistic I've felt about this project since I started trying to get a successful compilation a year ago. I'm so close to victory, but I'm getting some persistent buffer and sample errors that I do not know how to resolve. I tried a few manual fixes, but it kept going deeper and I feel like my idea was not a good solution. Any tips for this part? In file included from /Users/Documents/Arduino/ml_synth_organ_example/ml_synth_organ_example.ino:57: /Users/Documents/Arduino/ml_synth_organ_example/ml_synth_organ_example.ino: In function 'void setup()': /Users/Documents/Arduino/ml_synth_organ_example/ml_synth_organ_example.ino:152:17: error: 'SAMPLE_RATE' was not declared in this scope 152 | Organ_Setup(SAMPLE_RATE); | ^~~~~~~~~~~ /Users/Documents/Arduino/libraries/ML_SynthTools/src/ml_organ.h:83:47: note: in definition of macro 'Organ_Setup' 83 | #define Organ_Setup(...) OrganRP2350_Setup(__VA_ARGS__) | ^~~~~~~~~~~ /Users/Documents/Arduino/ml_synth_organ_example/ml_synth_organ_example.ino: In function 'void loop()': /Users/Documents/Arduino/ml_synth_organ_example/ml_synth_organ_example.ino:305:25: error: 'SAMPLE_RATE' was not declared in this scope 305 | if (loop_cnt_1hz >= SAMPLE_RATE) | ^~~~~~~~~~~ /Users/Documents/Arduino/ml_synth_organ_example/ml_synth_organ_example.ino:383:18: error: 'SAMPLE_BUFFER_SIZE' was not declared in this scope 383 | int32_t mono[SAMPLE_BUFFER_SIZE]; | ^~~~~~~~~~~~~~~~~~ /Users/Documents/Arduino/ml_synth_organ_example/ml_synth_organ_example.ino:384:23: error: 'mono' was not declared in this scope 384 | Organ_Process_Buf(mono, SAMPLE_BUFFER_SIZE); | ^~~~ /Users/Documents/Arduino/libraries/ML_SynthTools/src/ml_organ.h:85:59: note: in definition of macro 'Organ_Process_Buf' 85 | #define Organ_Process_Buf(...) OrganRP2350_Process_Buf(__VA_ARGS__) | ^~~~~~~~~~~ exit status 1

[@hastyman]

@@marcellicence thanks for your work on this. I'm seeing a few issues when compiling for sample and buffer. I attempted to manually correct that with the same settings I saw in the config.h file, but was unsuccessful. I'd appreciate any tips! Here are the messages I'm seeing when compiling: In file included from /Arduino/ml_synth_organ_example/ml_synth_organ_example.ino:57: /Arduino/ml_synth_organ_example/ml_synth_organ_example.ino: In function 'void setup()': /Arduino/ml_synth_organ_example/ml_synth_organ_example.ino:152:17: error: 'SAMPLE_RATE' was not declared in this scope 152 | Organ_Setup(SAMPLE_RATE); | ^~~~~~~~~~~ /Arduino/libraries/ML_SynthTools/src/ml_organ.h:83:47: note: in definition of macro 'Organ_Setup' 83 | #define Organ_Setup(...) OrganRP2350_Setup(__VA_ARGS__) | ^~~~~~~~~~~ /Arduino/ml_synth_organ_example/ml_synth_organ_example.ino: In function 'void loop()': /Arduino/ml_synth_organ_example/ml_synth_organ_example.ino:305:25: error: 'SAMPLE_RATE' was not declared in this scope 305 | if (loop_cnt_1hz >= SAMPLE_RATE) | ^~~~~~~~~~~ /Arduino/ml_synth_organ_example/ml_synth_organ_example.ino:383:18: error: 'SAMPLE_BUFFER_SIZE' was not declared in this scope 383 | int32_t mono[SAMPLE_BUFFER_SIZE]; | ^~~~~~~~~~~~~~~~~~ /Arduino/ml_synth_organ_example/ml_synth_organ_example.ino:384:23: error: 'mono' was not declared in this scope 384 | Organ_Process_Buf(mono, SAMPLE_BUFFER_SIZE); | ^~~~ /Arduino/libraries/ML_SynthTools/src/ml_organ.h:85:59: note: in definition of macro 'Organ_Process_Buf' 85 | #define Organ_Process_Buf(...) OrganRP2350_Process_Buf(__VA_ARGS__) | ^~~~~~~~~~~ exit status 1

[@marcellicence]

@@hastyman The organ project is not ready yet. I will take a look at it soon. You will find a list of compilable targets in the document in the doc folder. Thank you very much for your feedback. The configuration for RP2350 is missing here causing these errors.

[@GreatCaptainA]

what's the maximum polyphony you can get with the organ and with the fm synth?

[@marcellicence]

Hi the organ was running I think with 128 voices on the RP2350 (two manuals with 64 voices). The FM synth .. I can only guess about 12 with 4 operators. But I was working on a more optimized version too which would allow more voices

[@meneerjansen00]

Holy smoly! That sounds goor for a less than $10 chip! Will it also work w/ the orig. Pico?

[@marcellicence]

Hey, not exactly without changes because the RP2040 does not have the FPU. It would mean to rewrite the projects. I can imagine that you can achieve similar results.

[@howdydarlin344]

can you post the MIDI to UART circuit? thanks

[@marcellicence]

Hi, yes. I put some examples on GitHub: github.com/marcel-licence/ML_SynthTools/blob/main/extras/midi_input.md

[@sidthetech_USA]

Interesting... The midi comes in and goes 2-wire to the UART converter into the Pico. Would love to bridge my music gap with my arduino / SOC related hobbies... This is great... Thanks for the demo!

[@marcellicence]

There are a lot of possibilities using the Arduino platforms. This project was made without Arduino because I didn't find a library for the RP2350 yet. Thank you for your feedback

[@daliborlukas1700]

Hi, you are posting excellent projects, thank you! Is your organ/synth sound sampled as a wav, or as mp3-like, I mean only harmonics and compute FFT in real-time? I guess on pi pico 2 the latter approach could be possible thanks to the FPU, unlike on pico. Thanks!!

[@marcellicence]

@@daliborlukas1700 Hi, I don't use samples. It is computed in real-time. I hope I get some effects running on the pico 2 soon. Thank you very much