Hardware components | ||||||
 |
| × | 1 | |||
 |
| × | 1 | |||
 |
| × | 1 | |||
 |
| × | 1 | |||
This is a memorandum about HAGIWO/ハギヲ using seeed Xiao rp2040 and rasberry PI rp2040 to make your own VCO for the modular combiner.
background53rd self-made modular synth.I took a poll on my Youtube channel and the Rasberry pi pico VCO was the most popular. However, the Rasberry pi pico has only 3-pin AD converter, and I was worried that it was a little inconvenient to use it as a VCO.
Under such circumstances, Seeed studio released a small microcomputer board called Seeed Xiao RP2040. Since the AD converter has 4 pins, I thought that I could make a VCO with a minimum configuration, so I planned this module.
Eurorack standard 3U 6HP sizepower supply: 45mA (at 5V) Canoperate with a single 5V power supply.
Digital VCO with 3 modes: Wavefold, FM and AM.Audio output uses PWM to reduce costs.Each mode has 8 built-in waveforms.
FREQ POT : Adjust frequency. Since it is for tuning, the adjustable frequency range is narrow.MOD POT : Adjust the amount of modulation applied.MODE SW: Toggle switch to switch modesOCT SW: Switch octave. Three ranges of -1, 0, +1.PUSH SW : Switch the tone. Eight tones can be selected in each mode.
MOD CV : Adjust the amount of modulation applied. The input range is 0-5V.V/oct : Control frequency. Input range is 0-5V, resolution is 10bit.OUT: Audio output, output range is 5Vp-p.
In Wavefold mode, it can also be used as a basic waveform VCO.In FM mode, you can get soft sounds and industrial waveforms with intense overtones.AM mode is intended for use with metallic percussion, and contains sounds that contain non-integer overtones.
Total about 1100 yen---------------------------------Front panel 100 yenSeeed Xiao RP2040 600 yenToggle SW 20 yen *2pcsvariable resistor 30yen *2pcsoperational amplifier MPC6232 45yen etc.(see link below for general parts)
Seeed XIAO RP2040 is a microcomputer board equipped with the same RP2040 MCU as Rasberry pi pico. As for the number of AD converters, the pi pico has three, while the XIAO has four, making it easy to use.
Since the AD converter can read only up to 3.3V, the input range is expanded to 5V by dividing the voltage with resistors.The error of the voltage dividing resistance of the V/oct circuit is realized V/oct by performing software calibration.
Since the audio output is PWM, the output circuit has a 2-pole low-pass filter.It is amplified from 3.3Vp-p to 5Vp-p by an operational amplifier.Since it uses PWM, some harmonic noise is generated. If it bothers you, you should tune the low-pass filter.
2022/JUL/25 PostscriptThe toggle switch is an ON-OFF-ON 3-state switch.
NoteThere are multiple versions of the Seeed XIAO RP2040 schematic.The circuit diagram written as Ver1.08 is old and some circuits are different, so don't use it as a reference. Please refer to the circuit diagram written as the latest Ver1.22.
softwareNotes on introducing Seeed XIAO RP2040XIAO RP2040 can be developed with Arduino IDE.There is also a caveat here.When I installed the boards manager according to the software setup procedure on the official WIKI, writing failed in my environment.
XIAO RP2040 with Arduino - Seeed WikiSeed Product Documentwiki.seeedstudio.com
When I installed the board manager introduced by adafruit, I succeeded in writing.
Program RP2040 in ArduinoIn this guide, you'll learn how to install Earle Philhower'slearn.adafruit.com
It seems that other people have experienced similar problems, so if you fail to write with the Arduino IDE, you may want to suspect the board manager.
Baptism of XIAO RP2040 - ShigurememoIt's the consecutive holidays in May, and I thought I'd like to make something, so I bought the XIAO RP2040. I ordered it before the consecutive holidays and got it safely before the consecutive holidays. casuallymashigure.hateblo.jp
audio outputWaveforms are stored in a wavetable, interrupted at regular intervals, and the wavetable is read out to output audio. Wavetable is 10bit, 256 samples.In the August 2021 issue of the magazine Interfae, there was an article about a synthesizer using the Rasberry pi pico, and I used the source code as a reference. I could not understand 90% of what was written in my knowledge, but I was able to learn the concept of interrupt processing.
The source code is also available at the link below. Thanks!https://github.com/risgk/pico_synth_ex/blob/main/pico_synth_ex.c
You can also refer to this article. The concept of intervention is carefully explained.https://blog.boochow.com/article/pico-pwm-sound.html
There is a calibration constant to eliminate errors in the voltage divider resistance of the V/oct circuit.Calibrate by adjusting the value of calb in the range of about 0.7 to 1.3.
float calb = 1.19;//calibration for reduce resistance errorIn order to continue the open source project of DIY modular synth, we are looking for patrons on a service called patreon.I would appreciate it if you could help me with a cup of coffee.We also distribute content exclusive to patrons.
Source codeIt's crude, but it's open to the public. If there is a bad point, I would be happy if you could point it out.
#include <hardware/pwm.h>
int k = 1;
float AM_mod = 1;//AM modulation rate
float f = 0;
int slice_num = 0;
float osc_freq = 0;
bool push_sw, old_push_sw;//push sw
float mod = 0;
int wavetable[256];//1024 resolution , 256 rate
float mod_wavetable[256];//1st modulated wavetable
int mod2_wavetable[256];//2nd modulated wavetable
float calb = 1.15;//calibration for reduce resistance error
int adc, freq_pot, oct_sw, mode;
int waveform = 0;
int f0 = 35;//base osc frequency
long timer = 0;//use for making AM sinewave
const static float voctpow[1230] = {//Covers 6(=1230) octaves. If it is 1230 or more, the operation becomes unstable.
0, 0.004882, 0.009765, 0.014648, 0.019531, 0.024414, 0.029296, 0.034179, 0.039062, 0.043945, 0.048828, 0.05371, 0.058593, 0.063476, 0.068359, 0.073242, 0.078125, 0.083007, 0.08789, 0.092773, 0.097656, 0.102539, 0.107421, 0.112304, 0.117187, 0.12207, 0.126953, 0.131835, 0.136718, 0.141601, 0.146484, 0.151367, 0.15625, 0.161132, 0.166015, 0.170898, 0.175781, 0.180664, 0.185546, 0.190429, 0.195312, 0.200195, 0.205078, 0.20996, 0.214843, 0.219726, 0.224609, 0.229492, 0.234375, 0.239257, 0.24414, 0.249023, 0.253906, 0.258789, 0.263671, 0.268554, 0.273437, 0.27832, 0.283203, 0.288085, 0.292968, 0.297851, 0.302734, 0.307617, 0.3125, 0.317382, 0.322265, 0.327148, 0.332031, 0.336914, 0.341796, 0.346679, 0.351562, 0.356445, 0.361328, 0.36621, 0.371093, 0.375976, 0.380859, 0.385742, 0.390625, 0.395507, 0.40039, 0.405273, 0.410156, 0.415039, 0.419921, 0.424804, 0.429687, 0.43457, 0.439453, 0.444335, 0.449218, 0.454101, 0.458984, 0.463867, 0.46875, 0.473632, 0.478515, 0.483398, 0.488281, 0.493164, 0.498046, 0.502929, 0.507812, 0.512695, 0.517578, 0.52246, 0.527343, 0.532226, 0.537109, 0.541992, 0.546875, 0.551757, 0.55664, 0.561523, 0.566406, 0.571289, 0.576171, 0.581054, 0.585937, 0.59082, 0.595703, 0.600585, 0.605468, 0.610351, 0.615234, 0.620117, 0.625, 0.629882, 0.634765, 0.639648, 0.644531, 0.649414, 0.654296, 0.659179, 0.664062, 0.668945, 0.673828, 0.67871, 0.683593, 0.688476, 0.693359, 0.698242, 0.703125, 0.708007, 0.71289, 0.717773, 0.722656, 0.727539, 0.732421, 0.737304, 0.742187, 0.74707, 0.751953, 0.756835, 0.761718, 0.766601, 0.771484, 0.776367, 0.78125, 0.786132, 0.791015, 0.795898, 0.800781, 0.805664, 0.810546, 0.815429, 0.820312, 0.825195, 0.830078, 0.83496, 0.839843, 0.844726, 0.849609, 0.854492, 0.859375, 0.864257, 0.86914, 0.874023, 0.878906, 0.883789, 0.888671, 0.893554, 0.898437, 0.90332, 0.908203, 0.913085, 0.917968, 0.922851, 0.927734, 0.932617, 0.9375, 0.942382, 0.947265, 0.952148, 0.957031, 0.961914, 0.966796, 0.971679, 0.976562, 0.981445, 0.986328, 0.99121, 0.996093, 1.000976, 1.005859, 1.010742, 1.015625, 1.020507, 1.02539, 1.030273, 1.035156, 1.040039, 1.044921, 1.049804, 1.054687, 1.05957, 1.064453, 1.069335, 1.074218, 1.079101, 1.083984, 1.088867, 1.09375, 1.098632, 1.103515, 1.108398, 1.113281, 1.118164, 1.123046, 1.127929, 1.132812, 1.137695, 1.142578, 1.14746, 1.152343, 1.157226, 1.162109, 1.166992, 1.171875, 1.176757, 1.18164, 1.186523, 1.191406, 1.196289, 1.201171, 1.206054, 1.210937, 1.21582, 1.220703, 1.225585, 1.230468, 1.235351, 1.240234, 1.245117, 1.25, 1.254882, 1.259765, 1.264648, 1.269531, 1.274414, 1.279296, 1.284179, 1.289062, 1.293945, 1.298828, 1.30371, 1.308593, 1.313476, 1.318359, 1.323242, 1.328125, 1.333007, 1.33789, 1.342773, 1.347656, 1.352539, 1.357421, 1.362304, 1.367187, 1.37207, 1.376953, 1.381835, 1.386718, 1.391601, 1.396484, 1.401367, 1.40625, 1.411132, 1.416015, 1.420898, 1.425781, 1.430664, 1.435546, 1.440429, 1.445312, 1.450195, 1.455078, 1.45996, 1.464843, 1.469726, 1.474609, 1.479492, 1.484375, 1.489257, 1.49414, 1.499023, 1.503906, 1.508789, 1.513671, 1.518554, 1.523437, 1.52832, 1.533203, 1.538085, 1.542968, 1.547851, 1.552734, 1.557617, 1.5625, 1.567382, 1.572265, 1.577148, 1.582031, 1.586914, 1.591796, 1.596679, 1.601562, 1.606445, 1.611328, 1.61621, 1.621093, 1.625976, 1.630859, 1.635742, 1.640625, 1.645507, 1.65039, 1.655273, 1.660156, 1.665039, 1.669921, 1.674804, 1.679687, 1.68457, 1.689453, 1.694335, 1.699218, 1.704101, 1.708984, 1.713867, 1.71875, 1.723632, 1.728515, 1.733398, 1.738281, 1.743164, 1.748046, 1.752929, 1.757812, 1.762695, 1.767578, 1.77246, 1.777343, 1.782226, 1.787109, 1.791992, 1.796875, 1.801757, 1.80664, 1.811523, 1.816406, 1.821289, 1.826171, 1.831054, 1.835937, 1.84082, 1.845703, 1.850585, 1.855468, 1.860351, 1.865234, 1.870117, 1.875, 1.879882, 1.884765, 1.889648, 1.894531, 1.899414, 1.904296, 1.909179, 1.914062, 1.918945, 1.923828, 1.92871, 1.933593, 1.938476, 1.943359, 1.948242, 1.953125, 1.958007, 1.96289, 1.967773, 1.972656, 1.977539, 1.982421, 1.987304, 1.992187, 1.99707, 2.001953, 2.006835, 2.011718, 2.016601, 2.021484, 2.026367, 2.03125, 2.036132, 2.041015, 2.045898, 2.050781, 2.055664, 2.060546, 2.065429, 2.070312, 2.075195, 2.080078, 2.08496, 2.089843, 2.094726, 2.099609, 2.104492, 2.109375, 2.114257, 2.11914, 2.124023, 2.128906, 2.133789, 2.138671, 2.143554, 2.148437, 2.15332, 2.158203, 2.163085, 2.167968, 2.172851, 2.177734, 2.182617, 2.1875, 2.192382, 2.197265, 2.202148, 2.207031, 2.211914, 2.216796, 2.221679, 2.226562, 2.231445, 2.236328, 2.24121, 2.246093, 2.250976, 2.255859, 2.260742, 2.265625, 2.270507, 2.27539, 2.280273, 2.285156, 2.290039, 2.294921, 2.299804, 2.304687, 2.30957, 2.314453, 2.319335, 2.324218, 2.329101, 2.333984, 2.338867, 2.34375, 2.348632, 2.353515, 2.358398, 2.363281, 2.368164, 2.373046, 2.377929, 2.382812, 2.387695, 2.392578, 2.39746, 2.402343, 2.407226, 2.412109, 2.416992, 2.421875, 2.426757, 2.43164, 2.436523, 2.441406, 2.446289, 2.451171, 2.456054, 2.460937, 2.46582, 2.470703, 2.475585, 2.480468, 2.485351, 2.490234, 2.495117, 2.5, 2.504882, 2.509765, 2.514648, 2.519531, 2.524414, 2.529296, 2.534179, 2.539062, 2.543945, 2.548828, 2.55371, 2.558593, 2.563476, 2.568359, 2.573242, 2.578125, 2.583007, 2.58789, 2.592773, 2.597656, 2.602539, 2.607421, 2.612304, 2.617187, 2.62207, 2.626953, 2.631835, 2.636718, 2.641601, 2.646484, 2.651367, 2.65625, 2.661132, 2.666015, 2.670898, 2.675781, 2.680664, 2.685546, 2.690429, 2.695312, 2.700195, 2.705078, 2.70996, 2.714843, 2.719726, 2.724609, 2.729492, 2.734375, 2.739257, 2.74414, 2.749023, 2.753906, 2.758789, 2.763671, 2.768554, 2.773437, 2.77832, 2.783203, 2.788085, 2.792968, 2.797851, 2.802734, 2.807617, 2.8125, 2.817382, 2.822265, 2.827148, 2.832031, 2.836914, 2.841796, 2.846679, 2.851562, 2.856445, 2.861328, 2.86621, 2.871093, 2.875976, 2.880859, 2.885742, 2.890625, 2.895507, 2.90039, 2.905273, 2.910156, 2.915039, 2.919921, 2.924804, 2.929687, 2.93457, 2.939453, 2.944335, 2.949218, 2.954101, 2.958984, 2.963867, 2.96875, 2.973632, 2.978515, 2.983398, 2.988281, 2.993164, 2.998046, 3.002929, 3.007812, 3.012695, 3.017578, 3.02246, 3.027343, 3.032226, 3.037109, 3.041992, 3.046875, 3.051757, 3.05664, 3.061523, 3.066406, 3.071289, 3.076171, 3.081054, 3.085937, 3.09082, 3.095703, 3.100585, 3.105468, 3.110351, 3.115234, 3.120117, 3.125, 3.129882, 3.134765, 3.139648, 3.144531, 3.149414, 3.154296, 3.159179, 3.164062, 3.168945, 3.173828, 3.17871, 3.183593, 3.188476, 3.193359, 3.198242, 3.203125, 3.208007, 3.21289, 3.217773, 3.222656, 3.227539, 3.232421, 3.237304, 3.242187, 3.24707, 3.251953, 3.256835, 3.261718, 3.266601, 3.271484, 3.276367, 3.28125, 3.286132, 3.291015, 3.295898, 3.300781, 3.305664, 3.310546, 3.315429, 3.320312, 3.325195, 3.330078, 3.33496, 3.339843, 3.344726, 3.349609, 3.354492, 3.359375, 3.364257, 3.36914, 3.374023, 3.378906, 3.383789, 3.388671, 3.393554, 3.398437, 3.40332, 3.408203, 3.413085, 3.417968, 3.422851, 3.427734, 3.432617, 3.4375, 3.442382, 3.447265, 3.452148, 3.457031, 3.461914, 3.466796, 3.471679, 3.476562, 3.481445, 3.486328, 3.49121, 3.496093, 3.500976, 3.505859, 3.510742, 3.515625, 3.520507, 3.52539, 3.530273, 3.535156, 3.540039, 3.544921, 3.549804, 3.554687, 3.55957, 3.564453, 3.569335, 3.574218, 3.579101, 3.583984, 3.588867, 3.59375, 3.598632, 3.603515, 3.608398, 3.613281, 3.618164, 3.623046, 3.627929, 3.632812, 3.637695, 3.642578, 3.64746, 3.652343, 3.657226, 3.662109, 3.666992, 3.671875, 3.676757, 3.68164, 3.686523, 3.691406, 3.696289, 3.701171, 3.706054, 3.710937, 3.71582, 3.720703, 3.725585, 3.730468, 3.735351, 3.740234, 3.745117, 3.75, 3.754882, 3.759765, 3.764648, 3.769531, 3.774414, 3.779296, 3.784179, 3.789062, 3.793945, 3.798828, 3.80371, 3.808593, 3.813476, 3.818359, 3.823242, 3.828125, 3.833007, 3.83789, 3.842773, 3.847656, 3.852539, 3.857421, 3.862304, 3.867187, 3.87207, 3.876953, 3.881835, 3.886718, 3.891601, 3.896484, 3.901367, 3.90625, 3.911132, 3.916015, 3.920898, 3.925781, 3.930664, 3.935546, 3.940429, 3.945312, 3.950195, 3.955078, 3.95996, 3.964843, 3.969726, 3.974609, 3.979492, 3.984375, 3.989257, 3.99414, 3.999023, 4.003906, 4.008789, 4.013671, 4.018554, 4.023437, 4.02832, 4.033203, 4.038085, 4.042968, 4.047851, 4.052734, 4.057617, 4.0625, 4.067382, 4.072265, 4.077148, 4.082031, 4.086914, 4.091796, 4.096679, 4.101562, 4.106445, 4.111328, 4.11621, 4.121093, 4.125976, 4.130859, 4.135742, 4.140625, 4.145507, 4.15039, 4.155273, 4.160156, 4.165039, 4.169921, 4.174804, 4.179687, 4.18457, 4.189453, 4.194335, 4.199218, 4.204101, 4.208984, 4.213867, 4.21875, 4.223632, 4.228515, 4.233398, 4.238281, 4.243164, 4.248046, 4.252929, 4.257812, 4.262695, 4.267578, 4.27246, 4.277343, 4.282226, 4.287109, 4.291992, 4.296875, 4.301757, 4.30664, 4.311523, 4.316406, 4.321289, 4.326171, 4.331054, 4.335937, 4.34082, 4.345703, 4.350585, 4.355468, 4.360351, 4.365234, 4.370117, 4.375, 4.379882, 4.384765, 4.389648, 4.394531, 4.399414, 4.404296, 4.409179, 4.414062, 4.418945, 4.423828, 4.42871, 4.433593, 4.438476, 4.443359, 4.448242, 4.453125, 4.458007, 4.46289, 4.467773, 4.472656, 4.477539, 4.482421, 4.487304, 4.492187, 4.49707, 4.501953, 4.506835, 4.511718, 4.516601, 4.521484, 4.526367, 4.53125, 4.536132, 4.541015, 4.545898, 4.550781, 4.555664, 4.560546, 4.565429, 4.570312, 4.575195, 4.580078, 4.58496, 4.589843, 4.594726, 4.599609, 4.604492, 4.609375, 4.614257, 4.61914, 4.624023, 4.628906, 4.633789, 4.638671, 4.643554, 4.648437, 4.65332, 4.658203, 4.663085, 4.667968, 4.672851, 4.677734, 4.682617, 4.6875, 4.692382, 4.697265, 4.702148, 4.707031, 4.711914, 4.716796, 4.721679, 4.726562, 4.731445, 4.736328, 4.74121, 4.746093, 4.750976, 4.755859, 4.760742, 4.765625, 4.770507, 4.77539, 4.780273, 4.785156, 4.790039, 4.794921, 4.799804, 4.804687, 4.80957, 4.814453, 4.819335, 4.824218, 4.829101, 4.833984, 4.838867, 4.84375, 4.848632, 4.853515, 4.858398, 4.863281, 4.868164, 4.873046, 4.877929, 4.882812, 4.887695, 4.892578, 4.89746, 4.902343, 4.907226, 4.912109, 4.916992, 4.921875, 4.926757, 4.93164, 4.936523, 4.941406, 4.946289, 4.951171, 4.956054, 4.960937, 4.96582, 4.970703, 4.975585, 4.980468, 4.985351, 4.990234, 4.995117, 5, 5.004882, 5.009765, 5.014648, 5.019531, 5.024414, 5.029296, 5.034179, 5.039062, 5.043945, 5.048828, 5.05371, 5.058593, 5.063476, 5.068359, 5.073242, 5.078125, 5.083007, 5.08789, 5.092773, 5.097656, 5.102539, 5.107421, 5.112304, 5.117187, 5.12207, 5.126953, 5.131835, 5.136718, 5.141601, 5.146484, 5.151367, 5.15625, 5.161132, 5.166015, 5.170898, 5.175781, 5.180664, 5.185546, 5.190429, 5.195312, 5.200195, 5.205078, 5.20996, 5.214843, 5.219726, 5.224609, 5.229492, 5.234375, 5.239257, 5.24414, 5.249023, 5.253906, 5.258789, 5.263671, 5.268554, 5.273437, 5.27832, 5.283203, 5.288085, 5.292968, 5.297851, 5.302734, 5.307617, 5.3125, 5.317382, 5.322265, 5.327148, 5.332031, 5.336914, 5.341796, 5.346679, 5.351562, 5.356445, 5.361328, 5.36621, 5.371093, 5.375976, 5.380859, 5.385742, 5.390625, 5.395507, 5.40039, 5.405273, 5.410156, 5.415039, 5.419921, 5.424804, 5.429687, 5.43457, 5.439453, 5.444335, 5.449218, 5.454101, 5.458984, 5.463867, 5.46875, 5.473632, 5.478515, 5.483398, 5.488281, 5.493164, 5.498046, 5.502929, 5.507812, 5.512695, 5.517578, 5.52246, 5.527343, 5.532226, 5.537109, 5.541992, 5.546875, 5.551757, 5.55664, 5.561523, 5.566406, 5.571289, 5.576171, 5.581054, 5.585937, 5.59082, 5.595703, 5.600585, 5.605468, 5.610351, 5.615234, 5.620117, 5.625, 5.629882, 5.634765, 5.639648, 5.644531, 5.649414, 5.654296, 5.659179, 5.664062, 5.668945, 5.673828, 5.67871, 5.683593, 5.688476, 5.693359, 5.698242, 5.703125, 5.708007, 5.71289, 5.717773, 5.722656, 5.727539, 5.732421, 5.737304, 5.742187, 5.74707, 5.751953, 5.756835, 5.761718, 5.766601, 5.771484, 5.776367, 5.78125, 5.786132, 5.791015, 5.795898, 5.800781, 5.805664, 5.810546, 5.815429, 5.820312, 5.825195, 5.830078, 5.83496, 5.839843, 5.844726, 5.849609, 5.854492, 5.859375, 5.864257, 5.86914, 5.874023, 5.878906, 5.883789, 5.888671, 5.893554, 5.898437, 5.90332, 5.908203, 5.913085, 5.917968, 5.922851, 5.927734, 5.932617, 5.9375, 5.942382, 5.947265, 5.952148, 5.957031, 5.961914, 5.966796, 5.971679, 5.976562, 5.981445, 5.986328, 5.99121, 5.996093, 6.000976,
};
float freq_table[2048];
void setup1() {
}
void setup()
{
pinMode(0, INPUT_PULLUP);//oct select
pinMode(1, INPUT_PULLUP);//oct select
pinMode(6, INPUT_PULLUP);//push sw
pinMode(3, INPUT_PULLUP);//mode select
pinMode(4, INPUT_PULLUP);//mode select
timer = micros();
table_set();//set wavetable
//-------------------octave select-------------------------------
for (int i = 0; i < 1230; i++) {//Covers 6(=1230) octaves. If it is 1230 or more, the operation becomes unstable.
freq_table[i] = f0 * pow(2, (voctpow[i]));
}
for (int i = 0; i < 2048 - 1230; i++) {
freq_table[i + 1230] = 6;
}
//-------------------PWM setting-------------------------------
gpio_set_function(2, GPIO_FUNC_PWM);// set GP2 function PWM
slice_num = pwm_gpio_to_slice_num(2);// GP2 PWM slice
pwm_clear_irq(slice_num);
pwm_set_irq_enabled(slice_num, true);
irq_set_exclusive_handler(PWM_IRQ_WRAP, on_pwm_wrap);
irq_set_enabled(PWM_IRQ_WRAP, true);
//set PWM frequency
pwm_set_clkdiv(slice_num, 1);//=sysclock/((resolution+1)*frequency)
pwm_set_wrap(slice_num, 1023);//resolutio
pwm_set_enabled(slice_num, true);//PWM output enable
}
void on_pwm_wrap() {
pwm_clear_irq(slice_num);
f = f + osc_freq;
if (f > 255) {
f = 0;
}
int k = (int)f;
pwm_set_chan_level(slice_num, PWM_CHAN_A, mod2_wavetable[k] + 511);
}
void loop()
{
old_push_sw = push_sw;
//-------------------octave select-------------------------------
if (digitalRead(0) == 1 && digitalRead(1) == 1) {
oct_sw = 1;
}
else if (digitalRead(0) == 0 && digitalRead(1) == 1) {
oct_sw = 3;
}
else if (digitalRead(0) == 1 && digitalRead(1) == 0) {
oct_sw = 0;
}
// -------------------mode select-------------------------------
if (digitalRead(4) == 1 && digitalRead(3) == 1) {
mode = 1;//fm
}
else if (digitalRead(4) == 0 && digitalRead(3) == 1) {
mode = 0;//AM
}
else if (digitalRead(4) == 1 && digitalRead(3) == 0) {
mode = 2;//wavefolder
}
// -------------------frequeny calculation-------------------------------
adc = analogRead(26) * calb;//Correct resistance errors
adc = constrain(adc , 0, 1225) ;//Covers 6(=1220) octaves. If it is 1230 or more, the operation becomes unstable.
freq_pot = map(analogRead(27), 0, 1023, 0, 127);
osc_freq = freq_table[adc + freq_pot]; // V/oct apply
osc_freq = 256 * osc_freq / 122070 * (1 + oct_sw);
// -------------------mod parameter set-------------------------------
if (mode == 0) {//fold
mod = constrain(analogRead(29) + analogRead(28), 0, 1023) * 0.0036 + 0.90; //28 is CV , 29 is pot
}
else if (mode == 1) {//FM
mod = constrain(analogRead(29) + analogRead(28), 0, 1023) / 8;
}
else if (mode == 2) {//AM
mod = 1023 - constrain(analogRead(29) + analogRead(28), 0, 1023) ;
}
// -------------------push sw-------------------------------
push_sw = digitalRead(6);
if (push_sw == 0 && old_push_sw == 1) {//when push sw ON
waveform++;//change waveform
if (waveform > 7) {
waveform = 0;
}
if (mode == 0 || mode == 2) {
table_set();
}
}
//}
//void loop1() {//modulation
if (mode == 0 ) {//wavefold
for (int i = 0; i < 256; i++) {
mod_wavetable[i] = wavetable[i] * mod;
}
for (int i = 0; i < 256; i++) { //fold
if (mod_wavetable[i] > 511 && mod_wavetable[i] < 1023 + 512) {
mod2_wavetable[i] = 1024 - mod_wavetable[i];
}
else if (mod_wavetable[i] < -512 && mod_wavetable[i] > -1024 - 512) {
mod2_wavetable[i] = -1023 - mod_wavetable[i];
}
else if (mod_wavetable[i] < -1024 - 511) {
mod2_wavetable[i] = 2048 + mod_wavetable[i];
}
else if (mod_wavetable[i] > 1023 + 511) {
mod2_wavetable[i] = -2047 + mod_wavetable[i];
}
else {
mod2_wavetable[i] = mod_wavetable[i] ;
}
}
}
else if (mode == 1) {//FM
switch (waveform) {
case 0:
for (int i = 0; i < 256; i++) { //FM1
mod2_wavetable[i] = (sin(2 * M_PI * i / 256 + mod / 128 * sin(2 * M_PI * 3 * i / 256)) ) * 511;
}
break;
case 1:
for (int i = 0; i < 256; i++) { //FM2
mod2_wavetable[i] = (sin(2 * M_PI * i / 256 + mod / 128 * sin(2 * M_PI * 3 * i / 256 + mod / 128 * sin(2 * M_PI * 3 * i / 256))) ) * 511;
}
break;
case 2:
for (int i = 0; i < 256; i++) { //FM3
mod2_wavetable[i] = (sin(2 * M_PI * i / 256 + mod / 128 * sin(2 * M_PI * 5 * i / 256 + mod / 128 * sin(2 * M_PI * 7 * i / 256))) ) * 511;
}
break;
case 3:
for (int i = 0; i < 256; i++) { //FM4
mod2_wavetable[i] = (sin(2 * M_PI * i / 256 + mod / 128 * sin(2 * M_PI * 9 * i / 256 + mod / 128 * sin(2 * M_PI * 5 * i / 256))) ) * 511;
}
break;
case 4:
for (int i = 0; i < 256; i++) { //FM5
mod2_wavetable[i] = ((sin(2 * M_PI * i / 256 + mod / 128 * sin(2 * M_PI * 19 * i / 256)) ) + (sin(2 * M_PI * 3 * i / 256 + mod / 128 * sin(2 * M_PI * 7 * i / 256)) )) / 2 * 511;
}
break;
case 5:
for (int i = 0; i < 256; i++) { //FM6
mod2_wavetable[i] = ((sin(2 * M_PI * i / 256 + mod / 128 * sin(2 * M_PI * 7 * i / 124)) ) + (sin(2 * M_PI * 9 * i / 368 + mod / 128 * sin(2 * M_PI * 11 * i / 256)) )) * 511;
}
break;
case 6:
for (int i = 0; i < 256; i++) { //FM7
mod2_wavetable[i] = ((sin(2 * M_PI * i / 256 + mod / 128 * sin(2 * M_PI * 13 * i / 256)) ) + (sin(2 * M_PI * 17 * i / 111 + mod / 128 * sin(2 * M_PI * 19 * i / 89)) )) * 511;
}
break;
case 7:
for (int i = 0; i < 256; i++) { //FM8
mod2_wavetable[i] = (sin(2 * M_PI * i / 256 + mod / 128 * sin(2 * M_PI * 11 * i / 124 + mod / 128 * sin(2 * M_PI * 7 * i / 333 + mod / 128 * sin(2 * M_PI * 9 * i / 56)))) ) * 511;
}
break;
}
}
else if (mode == 2) {//AM
if (timer + mod <= micros()) {
k++;
if (k > 63) {
k = 0;
}
AM_mod = sin( 2 * M_PI * k / 63);//make modulation sine wave
for (int i = 0; i < 255 ; i++) {
mod2_wavetable[i] = wavetable[i] * AM_mod;//multiply AM sine wave
}
timer = micros();
}
}
}
void table_set() {//make wavetable
if (mode == 0) { //wavefold
switch (waveform) {
case 0:
for (int i = 0; i < 256; i++) { //saw
wavetable[i] = i * 4 - 512;
}
break;
case 1:
for (int i = 0; i < 256; i++) { //sin
wavetable[i] = (sin(2 * M_PI * i / 256)) * 511;
}
break;
case 2:
for (int i = 0; i < 128; i++) { //squ
wavetable[i] = 511;
wavetable[i + 128] = -511;
}
break;
case 3:
for (int i = 0; i < 128; i++) { //tri
wavetable[i] = i * 8 - 511;
wavetable[i + 128] = 511 - i * 8;
}
break;
case 4:
for (int i = 0; i < 128; i++) { //oct saw
wavetable[i] = i * 4 - 512 + i * 2;
wavetable[i + 128] = i * 2 - 256 + i * 4;
}
break;
case 5:
for (int i = 0; i < 256; i++) { //FM1
wavetable[i] = (sin(2 * M_PI * i / 256 + sin(2 * M_PI * 3 * i / 256)) ) * 511;
}
break;
case 6:
for (int i = 0; i < 256; i++) { //FM2
wavetable[i] = (sin(2 * M_PI * i / 256 + sin(2 * M_PI * 7 * i / 256))) * 511;
}
break;
case 7:
for (int i = 0; i < 256; i++) { //FM3
wavetable[i] = (sin(2 * M_PI * i / 256 + sin(2 * M_PI * 4 * i / 256 + sin(2 * M_PI * 11 * i / 256)))) * 511;
}
break;
}
}
else if (mode == 2) { //AM
switch (waveform) {
case 0:
for (int i = 0; i < 256; i++) { //saw
wavetable[i] = (sin(2 * M_PI * i / 256)) * 511;
}
break;
case 1:
for (int i = 0; i < 256; i++) { //fm1
wavetable[i] = (sin(2 * M_PI * i / 256 + sin(2 * M_PI * 3 * i / 256)) ) * 511;
}
break;
case 2:
for (int i = 0; i < 256; i++) { //fm2
wavetable[i] = (sin(2 * M_PI * i / 256 + sin(2 * M_PI * 5 * i / 256)) ) * 511;
}
break;
case 3:
for (int i = 0; i < 256; i++) { //fm3
wavetable[i] = (sin(2 * M_PI * i / 256 + sin(2 * M_PI * 4 * i / 256 + sin(2 * M_PI * 11 * i / 256)))) * 511;
}
break;
case 4:
for (int i = 0; i < 256; i++) { //non-integer multiplets fm1
wavetable[i] = (sin(2 * M_PI * i / 256 + sin(2 * M_PI * 1.28 * i / 256)) ) * 511;
}
break;
case 5:
for (int i = 0; i < 256; i++) { //non-integer multiplets fm2
wavetable[i] = (sin(2 * M_PI * i / 256 + sin(2 * M_PI * 3.19 * i / 256)) ) * 511;
}
break;
case 6:
for (int i = 0; i < 256; i++) { //non-integer multiplets fm3
wavetable[i] = (sin(2 * M_PI * i / 256 + sin(2 * M_PI * 2.3 * i / 256 + sin(2 * M_PI * 7.3 * i / 256)))) * 511;
}
break;
case 7:
for (int i = 0; i < 256; i++) { //non-integer multiplets fm3
wavetable[i] = (sin(2 * M_PI * i / 256 + sin(2 * M_PI * 6.3 * i / 256 + sin(2 * M_PI * 11.3 * i / 256)))) * 511;
}
break;
}
}
}If you want to know more, this link can help you
HAGIWO/ハギヲ
Posted by 
waniu
waniuThanks to HAGIWO/ハギヲ.
Comments