YetAnotherPWM.c with the Pic32MX250F128B

During one of my tests, i was scratching my head for ages about why the PWM signal wasnt coming out on one of the remappable pins PPS. Went through examples, family datasheet, etc...
 Only to come to the conclusion that it would never work without disabling the JTAG ports in the configuration bits.

YetAnotherpwm.X\anotherpwm.c

 1 /* 
 2  * File:   YetAnotherpwm.c
 3  * Author: Ras B.
 4  *
 5  * Created on 26 May 2015, 19:20
 6  */
 7 
 8 #include <plib.h>
 9 #include <p32xxxx.h>
10 
11 #pragma config   JTAGEN    = OFF // // disable the JTAG port  DDPCONbits.JTAGEN = 0;
12 #pragma config   FNOSC     = FRCPLL
13 #pragma config   FPLLIDIV  = DIV_2
14 #pragma config   FPLLMUL   = MUL_20
15 #pragma config   FPLLODIV  = DIV_2
16 #pragma config   FPBDIV    = DIV_1
17 #pragma config   POSCMOD   = OFF
18 #pragma config   FWDTEN    = OFF
19 //
20 #define GetSystemClock()        (40000000ul)
21 #define GetPeripheralClock()    (GetSystemClock()/(1<<OSCCONbits.PBDIV))// #define GetPeripheralClock()        (GetSystemClock()/(1<<OSCCONbits.PBDIV))
22 #define PWM_FREQ                33250
23 
24 volatile unsigned int incCount = 0; /*
25  * 
26  */
27 
28 void initAudio(void) {
29     // configures peripherals for Audio playback  
30     // Activate the PWM module
31     // OC1 in PWM mode, TMR2 based
32     OpenOC1(OC_ON | OC_TIMER2_SRC | OC_PWM_FAULT_PIN_DISABLE, 0, 0);
33     // timebase   
34     // enable TMR2, prescale 1:1, internal clock, period  
35     OpenTimer2(T2_ON | T2_PS_1_1 | T2_SOURCE_INT, 0);
36     mT2SetIntPriority(4);
37     // set TMR2 interrupt priority     
38 } // initAudio
39 
40 void startAudio(int bitrate) { // begins the audio playback
41     //  set the period for the given bitrate
42     PR2 = GetPeripheralClock() / bitrate - 1; //fpb
43     //  enable the interrupt state machine
44     mT2ClearIntFlag();
45     // clear interrupt flag   
46     mT2IntEnable(1);
47     // enable TMR2 interrupt      
48 } // startAudio
49 
50 void haltAudio(void) {
51     // stops playback state machine
52     mT2IntEnable(0);
53 } // halt audio
54 
55 main() {
56     SYSTEMConfig(GetPeripheralClock(), SYS_CFG_WAIT_STATES | SYS_CFG_PCACHE);
57     INTEnableSystemMultiVectoredInt();
58     //
59     TRISBbits.TRISB7 = 0; //Set port as output
60     RPB7Rbits.RPB7R = 0x0005;
61     mPORTAClearBits(BIT_0); //Clear bits to ensure light is off.
62     mPORTASetPinsDigitalOut(BIT_0); //Set port as output
63     //mPORTAClearBits(BIT_0); //Clear bits to ensure light is off.
64     // Set OC1 to pin RB7 with peripheral pin select
65     RPB7Rbits.RPB7R = 0x0005;
66     initAudio();
67     OC1RS = (PR2 + 1) * ((float) 50 / 100); // pwm duty cycle can be updated here on in interrupt
68     startAudio (PWM_FREQ);
69     //timer init
70     //mT2ClearIntFlag();
71     // clear interrupt flag
72     //mT2IntEnable(1);
73     //
74     while (1) {
75         if (incCount >= (PWM_FREQ/2)) {
76             incCount = 0;
77             mPORTAToggleBits(BIT_0);
78         }
79     }//while 1
80 }//main
81 
82 void __ISR(_TIMER_2_VECTOR, ipl4) T2Interrupt(void) {
83     // 
84     incCount++;
85     // 1. load the new samples for the next cycle  
86     OC1RS = (PR2 + 1) * ((float) 50 / 100);
87     // 2. clear interrupt flag and exit
88     mT2ClearIntFlag();
89 } // T2Interrupt  
90 

ChipKIT DP32 I2C Bus Speed with a MCP4725 DAC

Both arduino and MPIDE seem to have the I2C bus speed set to 100 kHz by default. So, here it is how to change it to 400kHz.

Inside the MPIDE folder, go to hardware\pic32\libraries\Wire\utility.

Inside file twi.h Find the string #define TWI_FREQ 100000 and change it to:  #defineTWI_FREQ 400000.

In my simple test i went from a 20Hz sinewave to a 72Hz just by effecting this change to the bus speed.

On the DP32 Board, SDA is assigned to Pin RB9 and SCL to Pin RB8.

Binary counter- 6 bit r2r DAC example for chipKit DP32 - PIC32MX250F128B

/*
Dubworks 6 bit r2r DAC example u4 LSB's using board leds 
 to display ;for chipKit DP32 board - PIC32MX250F128B

 @2014
 */
unsigned int i=0;
void setup(){
  Serial.begin(19200);
  LATBCLR = 0x3F;  // BIN 111111 ; 0xF for 4 leds only
  TRISBCLR =0x3F;  // Ports RB0-RB5 as Output ; 0xF for 4 leds only
}
void loop(){
  LATBCLR = 0x3F; //  clear 0xF for 4 leds only
  LATB |= i ;
  int a;
  a=PORTB;

  Serial.println(" I DEC ");
  Serial.println(i,DEC);
  Serial.println(" PORTD BIN ");
  Serial.println(a,BIN);

  i++;
  /* if you want to use the 5 bits of port B 0-4 */
  //  if(i < = 32){
  //    i=0; 
  //  }

  if(i < = 64){
    i=0;  
  }

  delay(250); //

}




note : P0-05 == RB0-RB5 ports

quick experiment with chipKit DP32 timers

quick experiment with chipKit DP32 timers

#include <sys/attribs.h>
#define WAVE_SAMPLES 256
uint16_t a;
uint16_t b;
uint16_t d;
uint16_t inc;
boolean c;

boolean togg;
uint16_t sineData [WAVE_SAMPLES];
//
void setup()
{
  Serial.begin(19200);
  initTmr();
  pinMode(A2, INPUT); //
  pinMode(13, OUTPUT); //LED
  sine ();  
}

void loop()
{
  uint16_t aIn =analogRead(A2);
  inc=aIn>>2;
  d=sineData[a];
  //  if(c !=togg){
  //    Serial.println(a);
  //    Serial.println(d);
  //    Serial.println("inc");
  //    Serial.println(inc);
  //    
  //    //Serial.println("togg");
  //    //Serial.println(togg,DEC);
  //  } //
  c=togg;
}

// call interrupt handling vector
extern "C" {

  void __ISR(16, ipl6) int1Handler(void) 
  {
    togg= !togg;
    analogWrite(13, d); //a++;
    //
    //
    a++;
    a+=inc;
    if(a>=WAVE_SAMPLES)
      a-=WAVE_SAMPLES;

    IFS0CLR = 0x80000;// Clear the T4 interrupt flag Bit 19
    //
  }
}

void initTmr(){
  // 
  T4CON=0x0; //Stop timer and clear registers
  T4CONSET = 0x0070; // set prescalar 1:256
  TMR4 = 0x0; //Clear Timer 4 register
  PR4 = 0x1D1; // set timer to 465 
  IFS0CLR = 0x80000;// Clear the T4 interrupt flag Bit 19
  IPC4SET = 0x00000016;// Interrupt priority 5, 2
  IEC0SET = 0x80000;// Enable T4 interrupt Bit 19
  T4CONSET = 0x8000;// Enable Timer4  
}
void sine (){
  uint16_t i;
  for(i=0;i<WAVE_SAMPLES;i++){
    b = 127*sin((2*PI/WAVE_SAMPLES)*i);
    b+=127;
    sineData [i]=b;
  }
}

Dub && Wise Synth

*some decoupling capacitors 100nFclose to the analog pins should be added.

My initial intention was to create something focused for the soundsystem culture. This turned out to be much more difficult than i thought .
Dub siren/Elec tom synth/And oscilattor+ MAD Lfos (some trying to recreate some of the sounds in a synare that Jah Shaka got us all used to)...All this synthesized on the fly with the help of some wavetables (all created during the start up)
.
Pots for :
-Oscillator wave selector ( Sine,cosine  Saw, Inverted Saw, Square wave, triangle and 1 extra slots for now )
-LFO rate
-LFO modulator type select ( Any of the above tables, plus a few more specific and tailored options)
-Attack
-Release
* Both attack and release can interact with the LFO
- Mode selector ( Dub Siren, Sound effects " a la Synare", Elec-Tom synth)

This video is just as an update on the proceedings.
Here i am using the Arduino Due.
Due to its complexity, i ended up re-writing the whole code from scratch and fresh to suit this specific idea.
Already started porting a similar idea to the chipKit DP32, and Pinguino and an Xmos version also soon to come, subject to availability of spare time.