Use PWM output on RP2040

[pierrotm777]

Problem Description

Try to read a header file and output an audio signal on pins 2 and 3 on a RP2040 Zero

Device Description

Waveshare RP2040 Zero

Sketch

#include "AudioTools.h"
#include "AudioCodecs/CodecMP3Helix.h"
#include "BabyElephantWalk60_mp3.h"

/*
EarPhone    ESP32   RPI Pico    MBED
Left        GPI2       GPI2       GPI2
Right     GPI3     GPIO3      GPI3
GND         GND        GND      GND
To verify check the PIN_PWM_START in AudioConfig.h or you can set the pins by calling setPins() method on the PWMConfig object.
*/
//PWMConfig config;

MemoryStream mp3(BabyElephantWalk60_mp3, BabyElephantWalk60_mp3_len);
PWMAudioOutput out;  // PWM output 
EncodedAudioStream decoded(&out, new MP3DecoderHelix()); // output to decoder
StreamCopy copier(decoded, mp3);    // copy in to out

void setup(){
  Serial.begin(115200);

  AudioLogger::instance().begin(Serial, AudioLogger::Info);  

  // begin processing
  auto cfg = out.defaultConfig();
  Pins pins = {2, 3};
  cfg.setPins(pins);//6 par défaut, voir 
  out.begin(cfg);

  decoded.begin();
}

void loop(){
  if (mp3) {
    copier.copy();
  } else {
    auto info = decoded.decoder().audioInfo();
    LOGI("The audio rate from the mp3 file is %d", info.sample_rate);
    LOGI("The channels from the mp3 file is %d", info.channels);
    out.end();
    stop();
  }
}

Other Steps to Reproduce

My scope see nothing on pin 2 or 3.

What is your development environment

Arduino IDE

I have checked existing issues, discussions and online documentation

• [X] I confirm I have checked existing issues, discussions and online documentation

[pschatzmann]

What is the logging output ? I am not sure what max sample rate the PWMAudioOutput supports on a RP2040. You might need to resample to a lower rate

[pierrotm777]

/ Restarting... [I] PWMAudioBase.h : 124 - decimation: 1 [I] PWMAudioBase.h : 87 - sample_rate: 8000 [I] PWMAudioBase.h : 88 - channels: 1 [I] PWMAudioBase.h : 89 - bits_per_sample: 16 [I] PWMAudioBase.h : 90 - buffer_size: 1024 [I] PWMAudioBase.h : 91 - buffer_count: 4 [I] PWMAudioBase.h : 92 - pwm_frequency: 30000 [I] PWMAudioBase.h : 93 - resolution: 8 [I] PWMAudioRP2040.h : 112 - ->wrap_value = 63 [I] PWMAudioRP2040.h : 113 - ->max clock speed = 133000000.000000 [I] PWMAudioRP2040.h : 114 - ->divider = 70.370369 [I] PWMAudioRP2040.h : 115 - ->clock speed = 1890000.000000 [I] PWMAudioRP2040.h : 92 - PWM pin 3 [I] PWMAudioBase.h : 153 - ->Buffer available: 0 [I] PWMAudioBase.h : 154 - ->Buffer available for write: 4096 [I] PWMAudioBase.h : 155 - ->is_timer_started: false [I] C:\tmp\Arduino_Compilateur\arduino-1.8.19\MyArduinoSketch\streams_memory_wav_pwm\streams_memory_wav_pwm.ino : 44 - The audio rate from the wav file is 44100 [I] C:\tmp\Arduino_Compilateur\arduino-1.8.19\MyArduinoSketch\streams_memory_wav_pwm\streams_memory_wav_pwm.ino : 45 - The channels from the wav file is 2 Restarting...

[pschatzmann]

I guess you will need to add a while(!Serial) delay(100); after Serial.begin() to get the full log

[pierrotm777]

I have tried the merge demo with success.

But PWM return no signal on the pin 3. [I] AudioTypes.h : 127 - sample_rate: 8000 / channels: 1 / bits_per_sample: 16 [I] PWMAudioBase.h : 124 - decimation: 1 [I] PWMAudioBase.h : 132 - ->Allocating new buffer 4 * 1024 bytes [I] Buffers.h : 372 - resize: 4096 [I] PWMAudioBase.h : 87 - sample_rate: 8000 [I] PWMAudioBase.h : 88 - channels: 1 [I] PWMAudioBase.h : 89 - bits_per_sample: 16 [I] PWMAudioBase.h : 90 - buffer_size: 1024 [I] PWMAudioBase.h : 91 - buffer_count: 4 [I] PWMAudioBase.h : 92 - pwm_frequency: 30000 [I] PWMAudioBase.h : 93 - resolution: 8 [I] PWMAudioRP2040.h : 112 - ->wrap_value = 63 [I] PWMAudioRP2040.h : 113 - ->max clock speed = 133000000.000000 [I] PWMAudioRP2040.h : 114 - ->divider = 70.370369 [I] PWMAudioRP2040.h : 115 - ->clock speed = 1890000.000000 [I] PWMAudioRP2040.h : 92 - PWM pin 3 [I] PWMAudioBase.h : 153 - ->Buffer available: 0 [I] PWMAudioBase.h : 154 - ->Buffer available for write: 4096 [I] PWMAudioBase.h : 155 - ->is_timer_started: false [I] C:\tmp\Arduino_Compilateur\arduino-1.8.19\MyArduinoSketch\streams_memory_mp3_pwm\streams_memory_mp3_pwm.ino : 52 - The audio rate from the mp3 file is 2010926598 [I] C:\tmp\Arduino_Compilateur\arduino-1.8.19\MyArduinoSketch\streams_memory_mp3_pwm\streams_memory_mp3_pwm.ino : 53 - The channels from the mp3 file is 55684

[pschatzmann]

There seems to be an issue with the mp3 decoder: mp3 should return true. What happens if you just leave the copy() in the loop ?

[pierrotm777]

yes, i have a signal now :-)

[pierrotm777]

[I] StreamCopy.h : 158 - StreamCopy::copy 1024 -> 1024 -> 1024 bytes - in 1 hops [I] StreamCopy.h : 158 - StreamCopy::copy 1024 -> 1024 -> 1024 bytes - in 1 hops [I] StreamCopy.h : 158 - StreamCopy::copy 1024 -> 1024 -> 1024 bytes - in 1 hops [I] StreamCopy.h : 158 - StreamCopy::copy 1024 -> 1024 -> 1024 bytes - in 1 hops [I] StreamCopy.h : 158 - StreamCopy::copy 1024 -> 1024 -> 1024 bytes - in 1 hops [I] StreamCopy.h : 158 - StreamCopy::copy 1024 -> 1024 -> 1024 bytes - in 1 hops [I] StreamCopy.h : 158 - StreamCopy::copy 1024 -> 1024 -> 1024 bytes - in 1 hops [I] StreamCopy.h : 158 - StreamCopy::copy 1024 -> 1024 -> 1024 bytes - in 1 hops [I] StreamCopy.h : 158 - StreamCopy::copy 1024 -> 1024 -> 1024 bytes - in 1 hops [I] StreamCopy.h : 158 - StreamCopy::copy 1024 -> 1024 -> 1024 bytes - in 1 hops [I] StreamCopy.h : 158 - StreamCopy::copy 1024 -> 1024 -> 1024 bytes - in 1 hops

[pschatzmann]

In the sketch you can replace if (mp3) with if (mp3.available()). Some time ago I have made a generic change that a class needs to have the AudioInfo defined to return true. This is valid for most of the audio classes except the MemoryStream. I committed a correction so that if (mp3) will work again.

[pierrotm777]

It's OK,

[I] AudioTypes.h : 127 - sample_rate: 8000 / channels: 1 / bits_per_sample: 16 [I] PWMAudioBase.h : 124 - decimation: 1 [I] PWMAudioBase.h : 132 - ->Allocating new buffer 4 * 1024 bytes [I] Buffers.h : 372 - resize: 4096 [I] PWMAudioBase.h : 87 - sample_rate: 8000 [I] PWMAudioBase.h : 88 - channels: 1 [I] PWMAudioBase.h : 89 - bits_per_sample: 16 [I] PWMAudioBase.h : 90 - buffer_size: 1024 [I] PWMAudioBase.h : 91 - buffer_count: 4 [I] PWMAudioBase.h : 92 - pwm_frequency: 30000 [I] PWMAudioBase.h : 93 - resolution: 8 [I] PWMAudioRP2040.h : 112 - ->wrap_value = 63 [I] PWMAudioRP2040.h : 113 - ->max clock speed = 133000000.000000 [I] PWMAudioRP2040.h : 114 - ->divider = 70.370369 [I] PWMAudioRP2040.h : 115 - ->clock speed = 1890000.000000 [I] PWMAudioRP2040.h : 92 - PWM pin 6 [I] PWMAudioBase.h : 153 - ->Buffer available: 0 [I] PWMAudioBase.h : 154 - ->Buffer available for write: 4096 [I] PWMAudioBase.h : 155 - ->is_timer_started: false [I] AudioEncoded.h : 321 - virtual void audio_tools::EncodedAudioOutput::addNotifyAudioChange(audio_tools::AudioInfoSupport&) [I] AudioTimerRP2040.h : 37 - timer time: 125 us [I] StreamCopy.h : 158 - StreamCopy::copy 1024 -> 1024 -> 1024 bytes - in 1 hops [I] StreamCopy.h : 158 - StreamCopy::copy 1024 -> 1024 -> 1024 bytes - in 1 hops [I] StreamCopy.h : 158 - StreamCopy::copy 1024 -> 1024 -> 1024 bytes - in 1 hops [I] StreamCopy.h : 158 - StreamCopy::copy 1024 -> 1024 -> 1024 bytes - in 1 hops [I] StreamCopy.h : 158 - StreamCopy::copy 1024 -> 1024 -> 1024 bytes - in 1 hops [I] StreamCopy.h : 158 - StreamCopy::copy 1024 -> 1024 -> 1024 bytes - in 1 hops [I] StreamCopy.h : 158 - StreamCopy::copy 1024 -> 1024 -> 1024 bytes - in 1 hops [I] StreamCopy.h : 158 - StreamCopy::copy 1024 -> 1024 -> 1024 bytes - in 1 hops [I] StreamCopy.h : 158 - StreamCopy::copy 1024 -> 1024 -> 1024 bytes - in 1 hops

[pierrotm777]

Thanks for your help. One question, i am a naval RC modelist and i should like use your lib for simulate a motor. But i should like that sound change with the motor's speed. Is it possible, if yes whitch demo would be the best for me. I should like to use wav from sd or hearder file (mp3 or wav).

[pschatzmann]

I guess a short WAV file stored in PSRAM will be sufficient since you can endlessly loop over it. To change the pitch you can dynamically resample. or use some pitch shifting

[pierrotm777]

Thanks again,

I see that

[pierrotm777]

I try this code:

`#include "AudioTools.h"

include "AudioCodecs/CodecMP3Helix.h"

include "BabyElephantWalk60_mp3.h"

/ EarPhone ESP32 RPI Pico MBED Left GPI2 GPI2 GPI2 Right GPI3 GPIO3 GPI3 GND GND GND GND To verify check the PIN_PWM_START in AudioConfig.h or you can set the pins by calling setPins() method on the PWMConfig object. / //PWMConfig config; MemoryStream mp3(BabyElephantWalk60_mp3, BabyElephantWalk60_mp3_len); PWMAudioOutput out; // PWM output ResampleStream resample(out); EncodedAudioStream decoded(&out, new MP3DecoderHelix()); // output to decoder StreamCopy copier(decoded, mp3); // copy in to out

void setup(){ Serial.begin(115200); while(!Serial) delay(100);

AudioLogger::instance().begin(Serial, AudioLogger::Info);

// define resampling info auto rcfg = resample.defaultConfig(); //rcfg.copyFrom(info); rcfg.step_size = 1.5; resample.begin(rcfg);

// begin processing // Define CSV Output auto config = out.defaultConfig(); config.sample_rate = sample_rate; config.channels = channels; out.begin(config);

decoded.begin(); }

void loop(){ if (mp3.available()) { copier.copy(); } else { auto info = decoded.decoder().audioInfo(); LOGI("The audio rate from the mp3 file is %d", info.sample_rate); LOGI("The channels from the mp3 file is %d", info.channels); out.end(); stop(); } }`

With an error: Compilation error: 'sample_rate' was not declared in this scope; did you mean 'samplerateTab'?

[pierrotm777]

Idem for channels

[pierrotm777]

Ok, i have found for sample_rate and channels.

But this code return an error: PitchShiftOutput<int16_t, VariableSpeedRingBuffer> pitchShift(out); <int16_t, VariableSpeedRingBuffer> pitchShift(out); StreamCopy copier(pitchShift, sound); // copies sound to out

Compilation error: expected unqualified-id before '>' token