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Last update 7 years 9 months
by Robert Lin
AMBmain.c/* * File: AMBmain.c * Author: Yixing Liu, Zhiyi Xiang, Ran An, Kejian Lin * Description: This code is for the Antique Music Box that utilize Reading SD * card through SPI module and connect with Smartphone in Bluetooth through UART * module * * Created on November 22, 2015, 3:52 PM */ #include "p33fxxxx.h" #include <stdio.h> #include <stdlib.h> #include <stddef.h> #include <stdbool.h> #include <xc.h> #include <math.h> #include <dsp.h> #include "configuration_pins.h" #include "VFDdisplayMessage.h" #include "VFDbar.h" #include "SD-SPI.h" #include "FSIO.h" #include "vs1053.h" #include "ADC.h" // External Oscillator _FOSCSEL(FNOSC_FRC); _FOSC(FCKSM_CSECMD & OSCIOFNC_OFF & POSCMD_HS); // Clock Switching is enabled and Fail Safe Clock Monitor is disabled // OSC2 Pin Function: OSC2 is Clock Output // Primary Oscillator Mode: XT Crystal _FWDT(FWDTEN_OFF); // Watchdog Timer Enabled/disabled by user software // (LPRC can be disabled by clearing SWDTEN bit in RCON register #define True 1 #define False 0 #define MAXBUFFERSIZE 32 #define SAMP_BUFF_SIZE 64 // Size of the input buffer per analog input #define SAMPLING_RATE 8000 /* = Rate at which input signal was sampled */ #define MAX_CHNUM 10 // Highest Analog input number enabled for alternate sampling #define log2N 6 #define fftPoints (1<<log2N) int BufferA[MAX_CHNUM+1][SAMP_BUFF_SIZE] __attribute__((space(dma),aligned(64))); //int BufferB[MAX_CHNUM+1][SAMP_BUFF_SIZE] __attribute__((space(dma),aligned(64))); int BufferB[64]; SearchRec file; unsigned char attributes = ATTR_HIDDEN | ATTR_SYSTEM | ATTR_READ_ONLY | ATTR_VOLUME| ATTR_ARCHIVE; char extention[] = "*.mp3"; int findfile = 0; FSFILE * pointer; unsigned char section[MAXBUFFERSIZE]; unsigned int timer_counter = 0; const fractcomplex twiddleFactors[] __attribute__ ((space(auto_psv), aligned (fftPoints * 2))) = { 0x7FFF, 0x0000, 0x7F62, 0xF374, 0x7D8A, 0xE707, 0x7A7D, 0xDAD8, 0x7642, 0xCF04, 0x70E3, 0xC3A9, 0x6A6E, 0xB8E3, 0x62F2, 0xAECC, 0x5A82, 0xA57E, 0x5134, 0x9D0E, 0x471D, 0x9592, 0x3C57, 0x8F1D, 0x30FC, 0x89BE, 0x2528, 0x8583, 0x18F9, 0x8276, 0x0C8C, 0x809E, 0x0000, 0x8000, 0xF374, 0x809E, 0xE707, 0x8276, 0xDAD8, 0x8583, 0xCF04, 0x89BE, 0xC3A9, 0x8F1D, 0xB8E3, 0x9592, 0xAECC, 0x9D0E, 0xA57D, 0xA57D, 0x9D0E, 0xAECC, 0x9592, 0xB8E3, 0x8F1D, 0xC3A9, 0x89BE, 0xCF04, 0x8583, 0xDAD8, 0x8276, 0xE707, 0x809E, 0xF374 }; #define FILTER_LEN 10 double FirCoeff[ FILTER_LEN ] ={-1468, 1058, 594, 287, 186, 284, 485, 613, 495, 90 }; int index = 50000; int DMA_counter = 0; fractional inputData[fftPoints]; // Initial FFTdata fractcomplex fftData[fftPoints] __attribute__ ((section (".ybss, bss, ymemory"), aligned (fftPoints * 2 * 2))); fractional powerSpec[fftPoints/2]; unsigned short int currentVolume, scibass=0, memtest=0, clock=0, scimode=0, scistatus=0, hdat0=0, hdat1=0, samplerate=0; void InitClock(void); void InitSPI(void); void Init_Timer1( void ); void Init_Timer2 (void); void InitUART1(void); void ws2812_send(ws2812_ptr); void initAdc1(void); void initTmr3(); void initDma0(void); void __attribute__((__interrupt__)) _DMA0Interrupt(void); void ProcessADCSamples(int * AdcBuffer); void FFT(int * inputData); void RunFIRFilter(double *FirCoeff, int NumTaps, double *Signal, int NumSigPts); int timer1_counter = 0; int timer2_counter = 0; int tick = 0; int second=0; int minute=0; int hour=0; int song_is_over = 0; int SD = 0; int BT = 0; int RECEIVE; int play = 0; int stop = 0; int next = 0; int first = 0; int next_timer = 0; int led_i = 0; //int index = 50000; char str[4] = {0}; long data[10] = {1,2,3,4,5,6,7,7,6,5}; unsigned long int bitflip(unsigned char b); typedef struct { unsigned char r; unsigned char b; unsigned char g; } ws2812_ptr; ws2812_ptr led; #define FCY 9000000 #define BAUDRATE 115200 #define BRGVAL FCY/BAUDRATE/4 - 1 void __attribute__((__interrupt__, no_auto_psv)) _T1Interrupt(void) { /* Interrupt Service Routine code goes here */ IFS0bits.T1IF = 0; //Clear Timer1 interrupt flag T1CONbits.TON = 0; // disable timer timer1_counter ++; if(timer1_counter == 1000) { LATAbits.LATA13 = !LATAbits.LATA13; second = second + 1; if(second == 60) { minute = minute + 1; second = 0; } if(minute == 60) { hour = hour + 1; minute = 0; } if(hour == 12 && minute==60) { hour = 0; minute = 0; second = 0; } timer1_counter = 0; } TMR1 = 0; T1CONbits.TON = 1; } void __attribute__((__interrupt__, no_auto_psv)) _T2Interrupt(void) { /* Interrupt Service Routine code goes here */ IFS0bits.T2IF = 0; //Clear Timer1 interrupt flag T2CONbits.TON = 0; // disable timer if(play == 1) { if(index < 25000) VFDbar(data,1); else VFDbar(data,1); index--; if(index == 0) index = 50000; } if(play == 0) { // if(index < 25000) // VFDbar(data,0); // else // VFDbar(data,0); // index--; // if(index == 0) // index = 50000; } TMR2 = 0; T2CONbits.TON = 1; // if(next == 1) // { // if(index < 25000) // VFDbar(data); // else // VFDbar(data); // index--; // if(index == 0) // index = 50000; // } // if(led_i <= 3) // { // LED_VFD = 1; // LED_BAR = 1; // led_i++; // } // else // { // LED_VFD = 0; // LED_BAR = 1; // led_i++; // } // if(led_i == 10) // led_i = 0; } void __attribute__((__interrupt__, no_auto_psv)) _T3Interrupt(void) { /* Interrupt Service Routine code goes here */ IFS0bits.T3IF = 0; //Clear Timer3 interrupt flag T3CONbits.TON = 0; // disable timer TMR3 = 0; T3CONbits.TON = 1; } void __attribute__ ((interrupt, no_auto_psv)) _U1RXInterrupt(void) { if(U1STAbits.OERR == 1) { U1STAbits.OERR = 0; } RECEIVE = U1RXREG; { if(RECEIVE == 'c') { if(play == 0) { play = 1; } else { play = 0; } } if(RECEIVE == 'd') { next = 1; } if( RECEIVE == 'a') { SD = 1; BT = 0; mux1 = 0; mux2 = 0; // mux1 = mux2 = 0 = SD card } if( RECEIVE == '5') { BT = 1; SD = 0; play = 0; next = 0; mux1 = 1; mux2 = 1; // mux1 = mux2 = 1 = BT VFDdisplayMessage(" Morning "); } if( RECEIVE == '6') { BT = 1; SD = 0; play = 0; next = 0; mux1 = 1; mux2 = 1; // mux1 = mux2 = 1 = BT VFDdisplayMessage("Afternoon "); } if( RECEIVE == '7') { BT = 1; SD = 0; play = 0; next = 0; mux1 = 1; mux2 = 1; // mux1 = mux2 = 1 = BT VFDdisplayMessage("Evening"); } } IFS0bits.U1RXIF = 0; } // unsigned int DmaBuffer = 0; void __attribute__((interrupt, no_auto_psv)) _DMA0Interrupt(void) { RunFIRFilter( &FirCoeff, 10, &BufferA[10][0], 10); // if(play == 1) // ProcessADCSamples(&BufferA[10][0]); // int i; // for(i=0;i<16;i++) // { // BufferB[j] = BufferA[10][i]; // j++; // } // if( DMA_counter == 3) // { // ProcessADCSamples(&BufferB); // DMA_counter = 0; // j = 0; // } // DMA_counter ++; IFS0bits.DMA0IF = 0; //Clear the DMA0 Interrupt Flag } int main(void) { Configure_Pins(); //InitClock(); // VFDdisplayMessage("HelloWorld"); // while(1) { // // timing on the WS2812B is very precise. turn off interrupts before talking // //GIE = 0; while (GIE); // ws2812_send(&led); // //GIE = 1; while (!GIE); // led.b = 0; // delay(10); // ws2812_send(&led); // delay(10); // led.b = 120; // } VFDdisplayMessage("Welcome "); delay(200); InitClock(); Init_Timer1(); // Init_Timer2(); // Peripheral Initialisation //initAdc1(); // Initialize the A/D converter to convert Channel 5 //initDma0(); // Initialise the DMA controller to buffer ADC data in conversion order //while(1); InitSPI(); vs1053Config(); // Open SPI2 and Set Pin vs1053Reset(); // Reset MP3 Player vs1053Init(); // initializes the vs1053 mp3 player to "New" modes scimode = vs1053SCIRead(SCI_MODE); scistatus = vs1053SCIRead(SCI_STATUS); vs1053SCIWrite(SCI_BASS, 0x44); scibass = vs1053SCIRead(SCI_BASS); clock = vs1053SCIRead(SCI_CLOCKF); vs1053SCIWrite(SCI_AUDATA, 0xAC45); samplerate = vs1053SCIRead(SCI_AUDATA); while(!MDD_MediaDetect()) { VFDdisplayMessage("No media "); } FSInit(); findfile = FindFirst(extention,attributes,&file); if ( findfile == 0) { first = 1; pointer = FSfopen(file.filename,"r"); // open current file } delay(100); // test adc led.r = 120; led.g = 120; led.b = 120; // Peripheral Initialisation // Initialise the Timer to generate sampling event to ADC @ 8Khz rate VFDdisplayMessage("Play Song "); InitUART1(); // initAdc1(); // Initialize the A/D converter to convert Channel 5 // initDma0(); // Initialise the DMA controller to buffer ADC data in conversion order // initTmr3(); while(1) { if(play == 1) { if(first == 1) { VFDdisplayMessage(file.filename); first = 0; } while(1) { if(next == 1 || song_is_over == 1) { findfile = FindNext(&file); if(findfile != 0) { findfile = FindFirst(extention,attributes,&file); } } if(findfile == 0) // file find success { if(song_is_over == 1||next == 1) { VFDdisplayMessage(file.filename); pointer = FSfopen(file.filename,"r"); // open current file next = 0; song_is_over = 0; } if(pointer == NULL) while(1); while(FSfeof(pointer) == 0) { FSfread(section,1,MAXBUFFERSIZE,pointer); while(X_DREQ != 1); vs1053SendMusic(section,MAXBUFFERSIZE); if(play == 0 || next == 1) break; } if(FSfeof(pointer) != 0) { song_is_over = 1; } FSfclose(pointer); SendZerosToVS1053(); } else VFDdisplayMessage("Insert SD"); if( play == 0 ) break; } } if(play == 0) { // // char time[10]={0}; // time[0] = hour; // time[1] = minute; // time[2] =':'; // time[3] = second; // time[4] = '\0'; // VFDdisplayMessage(time); if(play == 1) break; next = 0; // VFDdisplayMessage("Bluetooth"); } } } void RunFIRFilter(double *FirCoeff, int NumTaps, double *Signal,int NumSigPts) { int j, k, n, Top = 0; double y, Reg[NumTaps]; // This assumes <= 256 taps. int FilteredSignal[10] = {0}; for(j=0; j<NumTaps; j++)Reg[j] = 0.0; for(j=0; j<NumSigPts; j++) { Reg[Top] = Signal[j]; y = 0.0; n = 0; // The FirCoeff index increases while the Reg index decreases. for(k=Top; k>=0; k--) { y += FirCoeff[n++] * Reg[k]; } for(k=NumTaps-1; k>Top; k--) { y += FirCoeff[n++] * Reg[k]; } FilteredSignal[j] = y; Top++; if(Top >= NumTaps)Top = 0; } } //void ProcessADCSamples(int * AdcBuffer) //{ // /* Do something with ADC Samples */ // int indata; // int writedata; // for(writedata = 0; writedata < fftPoints; writedata++){ // indata = *AdcBuffer++ - 2048; // // inputData[writedata] = indata << 4; // if(writedata == fftPoints - 1){ // FFT(inputData); // writedata = 0; // } // } //} void FFT(int * inputData) { int VFDdata[10]; fractional VFD[10]; int index = 0; int i; for(i = 0; i < fftPoints; i++) { fftData[i].real = inputData[i]; fftData[i].imag = 0; } FFTComplexIP( log2N, fftData, (fractcomplex *)twiddleFactors,(int) __builtin_psvpage(&twiddleFactors[0])); BitReverseComplex( log2N, fftData ); SquareMagnitudeCplx( fftPoints, fftData, powerSpec ); for(i=0;i<30;i++) { if((i%3)==2) { VFD[index] = (powerSpec[i] + powerSpec[i-1] + powerSpec[i-2]) / 3; index++; } } for(index=0;index<10;index++) { if(VFD[index]>0x100) VFDdata[index] = 0; else if(VFD[index] > 0xDC) VFDdata[index] = 1; else if(VFD[index] > 0xB8) VFDdata[index] = 2; else if(VFD[index] > 0x94) VFDdata[index] = 3; else if(VFD[index] > 0x70) VFDdata[index] = 4; else if(VFD[index] > 0x4C) VFDdata[index] = 5; else if(VFD[index] > 0x28) VFDdata[index] = 6; else VFDdata[index] = 7; } VFDbar(VFDdata,1); // /* Find the frequency Bin ( = index into the SigCmpx[] array) that has the largest energy*/ // /* i.e., the largest spectral component */ // VectorMax(fftPoints/2, powerSpec, &peakFrequencyBin); // /* Compute the frequency (in Hz) of the largest spectral component */ // peakFrequency = peakFrequencyBin*(SAMPLING_RATE/fftPoints); i = 0; } void initAdc1(void) { AD1CON1bits.FORM = 3; // Data Output Format: Signed Fraction (Q15 format) AD1CON1bits.SSRC = 2; // Sample Clock Source: GP Timer starts conversion AD1CON1bits.ASAM = 1; // ADC Sample Control: Sampling begins immediately after conversion AD1CON1bits.AD12B = 0; // 10-bit ADC operation AD1CON2bits.ALTS=1; // Alternate Input Sample Mode Select Bit AD1CON2bits.CHPS = 0; // Converts CH0 AD1CON3bits.ADRC = 0; // ADC Clock is derived from Systems Clock AD1CON3bits.ADCS = 63; // ADC Conversion Clock Tad=Tcy*(ADCS+1)= (1/9M)*64 = 1.6us (140.625Khz) // ADC Conversion Time for 10-bit Tc=12*Tab = AD1CON1bits.ADDMABM = 0; // DMA buffers are built in scatter/gather mode AD1CON2bits.SMPI = 0; // SMPI Must be programmed to 1 for this case AD1CON4bits.DMABL = 6; // Each buffer contains 64 words //AD1CHS0: A/D Input Select Register AD1CHS0bits.CH0SA = 10; // MUXA +ve input selection (AIN10) for CH0 AD1CHS0bits.CH0NA=0; // MUXA -ve input selection (Vref-) for CH0 AD1CSSLbits.CSS10 = 1; // select AN10 for input scan // AD1CHS0bits.CH0SB=10; // MUXB +ve input selection (AIN5) for CH0 // AD1CHS0bits.CH0NB=0; // MUXB -ve input selection (Vref-) for CH0 //AD1PCFGH/AD1PCFGL: Port Configuration Register // AD1PCFGL=0xFFFF; // AD1PCFGH=0xFFFF; AD1PCFGLbits.PCFG10 = 0; // AN10 as Analog Input // AD1PCFGLbits.PCFG10 = 0; // AN5 as Analog Input IFS0bits.AD1IF = 0; // Clear the A/D interrupt flag bit IEC0bits.AD1IE = 0; // Do Not Enable A/D interrupt AD1CON1bits.ADON = 1; // Turn on the A/D converter } void InitSPI(void) { SPI1CON1bits.DISSCK = 0; //SCK pin is controlled by SPI module SPI1CON1bits.DISSDO = 0; //SDO pin is controlled by SPI module SPI1CON1bits.MODE16 = 0; //8-bit mode selected SPI1CON1bits.SMP = 0; //sample data in midle of data output time SPI1CON1bits.CKE = 1; //positive clock edge selected SPI1CON1bits.SSEN = 0; //master mode, SS pin is not used SPI1CON1bits.CKP = 0; //clock active high SPI1CON1bits.MSTEN = 1; //select master mode SPI1CON1bits.SPRE = 0b101; //secondary scale 1:4 SPI1CON1bits.PPRE = 0b11; //primary scale 1:1 SPI1STATbits.SPIROV = 0; //clear overflow flag SPI1STATbits.SPIEN = 1; //enable SPI module; config SDI, SDO, SCK pins SPI1STATbits.SPISIDL = 0; //halt the module in idle state SPI1STATbits.SPITBF = 0; //clear TX buffer full flag SPI1STATbits.SPIRBF = 0; //clear RX buffer full flag SPI2CON1bits.DISSCK = 0; //SCK pin is controlled by SPI module SPI2CON1bits.DISSDO = 0; //SDO pin is controlled by SPI module SPI2CON1bits.MODE16 = 0; //8-bit mode selected SPI2CON1bits.SMP = 0; //sample data in midle of data output time SPI2CON1bits.CKE = 1; //positive clock edge selected SPI2CON1bits.SSEN = 0; //master mode, SS pin is not used SPI2CON1bits.CKP = 0; //clock active high SPI2CON1bits.MSTEN = 1; //select master mode SPI2CON1bits.SPRE = 0b101; //secondary scale 1:4 SPI2CON1bits.PPRE = 0b11; //primary scale 1:1 SPI2STATbits.SPIROV = 0; //clear overflow flag SPI2STATbits.SPIEN = 1; //enable SPI module; config SDI, SDO, SCK pins SPI2STATbits.SPISIDL = 0; //halt the module in idle state SPI2STATbits.SPITBF = 0; //clear TX buffer full flag SPI2STATbits.SPIRBF = 0; //clear RX buffer full flag } void InitClock() { PLLFBD = 4; // CLKDIVbits.PLLPOST = 0; // N1 = 2 CLKDIVbits.PLLPRE = 0; // N2 = 2 OSCTUN = 0; RCONbits.SWDTEN = 0; // Clock switch to incorporate PLL NOSC = 0b010 __builtin_write_OSCCONH(0b011); __builtin_write_OSCCONL(0b001); // Start clock switching while (OSCCONbits.COSC != 0b011); // Wait for Clock switch to occur while(OSCCONbits.LOCK != 1) {}; } void Init_Timer1(void) { T1CONbits.TON = 0; // Disable Timer T1CONbits.TCS = 0; // Select internal instruction cycle clock T1CONbits.TGATE = 0; // Disable Gated Timer mode T1CONbits.TCKPS = 0b10;// Select 1:64 Prescaler TMR1 = 0x00; // Clear timer register PR1 = 164; IPC0bits.T1IP = 0x01; // Set Timer1 Interrupt Priority Level IFS0bits.T1IF = 0; // Clear Timer1 Interrupt Flag IEC0bits.T1IE = 1; // Enable Timer1 interrupt T1CONbits.TON = 1; } void Init_Timer2(void) { T2CONbits.TON = 0; // Disable Timer T2CONbits.TCS = 0; // Select internal instruction cycle clock T2CONbits.TGATE = 0; // Disable Gated Timer mode T2CONbits.TCKPS = 0b11;// Select 1:256 Prescaler TMR2 = 0x00; // Clear timer register PR2 = 2000; IPC1bits.T2IP = 0x05; // Set Timer2 Interrupt Priority Level IFS0bits.T2IF = 0; // Clear Timer2 Interrupt Flag IEC0bits.T2IE = 1; // Enable Timer2 interrupt T2CONbits.TON = 1; } void initTmr3() { // TMR3 = 0x0000; // PR3 = 17578; // IFS0bits.T3IF = 0; // IEC0bits.T3IE = 0; // // //Start Timer 3 // T3CONbits.TON = 1; T3CONbits.TON = 0; // Disable Timer T3CONbits.TCS = 0; // Select internal instruction cycle clock T3CONbits.TGATE = 0; // Disable Gated Timer mode //T3CONbits.TCKPS = 0b11; // Select 1:256 Prescaler TMR3 = 0x00; // Clear timer register PR3 =17578; IPC2bits.T3IP = 0x5; // Set Timer2 Interrupt Priority Level IFS0bits.T3IF = 0; // Clear Timer2 Interrupt Flag IEC0bits.T3IE = 1; // Enable Timer2 interrupt T3CONbits.TON = 1; } void initDma0(void) { DMA0CONbits.AMODE = 2; // Configure DMA for Peripheral indirect mode DMA0CONbits.MODE = 2; // Configure DMA for Continuous Ping-Pong mode IPC1bits.DMA0IP = 1; DMA0PAD=(int)&ADC1BUF0; DMA0CNT = (SAMP_BUFF_SIZE*2)-1; DMA0REQ=13; DMA0STA = __builtin_dmaoffset(BufferA); //DMA0STB = __builtin_dmaoffset(BufferB); IFS0bits.DMA0IF = 0; //Clear the DMA interrupt flag bit IEC0bits.DMA0IE = 1; //Set the DMA interrupt enable bit IPC1bits.DMA0IP = 4; DMA0CONbits.CHEN=1; } void InitUART1(void) { // This is an EXAMPLE, so brutal typing goes into explaining all bit sets // The HPC16 board has a DB9 connector wired to UART1, so we will // be configuring this port only PMD1bits.U1MD = 0; // configure U1MODE U1MODEbits.UARTEN = 0; // Bit15 TX, RX DISABLED, ENABLE at end of func //U1MODEbits.notimplemented; // Bit14 U1MODEbits.USIDL = 0; // Bit13 Continue in Idle U1MODEbits.IREN = 0; // Bit12 No IR translation U1MODEbits.RTSMD = 0; // Bit11 Simplex Mode //U1MODEbits.notimplemented; // Bit10 U1MODEbits.UEN = 0; // Bits8,9 TX,RX enabled, CTS,RTS not U1MODEbits.WAKE = 0; // Bit7 No Wake up (since we don't sleep here) U1MODEbits.LPBACK = 0; // Bit6 No Loop Back U1MODEbits.ABAUD = 0; // Bit5 No Autobaud (would require sending '55') U1MODEbits.URXINV = 0; // Bit4 IdleState = 1 (for dsPIC) U1MODEbits.BRGH = 1; // Bit3 16 clocks per bit period U1MODEbits.PDSEL = 0; // Bits1,2 8bit, No Parity U1MODEbits.STSEL = 0; // Bit0 One Stop Bit U1BRG = BRGVAL; // Load all values in for U1STA SFR U1STAbits.UTXISEL1 = 0; //Bit15 Int when Char is transferred (1/2 config!) U1STAbits.UTXINV = 0; //Bit14 N/A, IRDA config U1STAbits.UTXISEL0 = 0; //Bit13 Other half of Bit15 //U2STAbits.notimplemented = 0; //Bit12 U1STAbits.UTXBRK = 0; //Bit11 Disabled U1STAbits.UTXEN = 0; //Bit10 TX pins controlled by periph U1STAbits.UTXBF = 0; //Bit9 *Read Only Bit* U1STAbits.TRMT = 0; //Bit8 *Read Only bit* U1STAbits.URXISEL = 0; //Bits6,7 Int. on character recieved U1STAbits.ADDEN = 0; //Bit5 Address Detect Disabled U1STAbits.RIDLE = 0; //Bit4 *Read Only Bit* U1STAbits.PERR = 0; //Bit3 *Read Only Bit* U1STAbits.FERR = 0; //Bit2 *Read Only Bit* U1STAbits.OERR = 0; //Bit1 *Read Only Bit* U1STAbits.URXDA = 0; //Bit0 *Read Only Bit* //IPC7 = 0x4400; // Mid Range Interrupt Priority level, no urgent reason IPC2bits.U1RXIP = 7; IFS0bits.U1TXIF = 0; // Clear the Transmit Interrupt Flag IEC0bits.U1TXIE = 0; // Enable Transmit Interrupts IFS0bits.U1RXIF = 0; // Clear the Receive Interrupt Flag IEC0bits.U1RXIE = 1; // Enable Receive Interrupts U1MODEbits.UARTEN = 1; // And turn the peripheral on U1STAbits.UTXEN = 1; } // transmit the ws2812 led void ws2812_send(ws2812_ptr* led) { int j; int i; long int val; // the WS2812 wants bits in the order of: // GGGGGGGGRRRRRRRRBBBBBBBB // but I want to work in the opposite order. so i'm going to flip // the bits around and do some shifting so my order is // BBBBBBBBRRRRRRRRGGGGGGGG // with the most significant bit on the far right. so the RGB value // of 128 64 32, which normally would be: // R : 0b10000000 // G : 0b01000000 // B : 0b00100000 // will become: // BBBBBBBBRRRRRRRRGGGGGGGG // 000001000000000100000010 val = (bitflip(led->b) << 16) + (bitflip(led->r) << 8) + (bitflip(led->g)); // now begin shifting them over one at a time for(i=0;i<8;i++) { for(j = 0; j < 24; j++) { // depending on if the currently viewed bit is 1 or 0 // the pin will stay high for different times if (val & 1 == 1) { // if it is a 1, let it stay higher a bit longer LED_BAR = 1; LED_VFD = 1; for(i=0;i<4;i++); LED_BAR = 0; LED_VFD = 0; } else { // but a 0 should go high and then low as fast as possible LED_BAR = 1; LED_BAR = 0; LED_VFD = 1; LED_VFD = 0; } // and then right shift to get the next bit val = val >> (unsigned char)1; } } } // reverse the bits in a char unsigned long int bitflip(unsigned char b) { b = (b & 0xF0) >> 4 | (b & 0x0F) << 4; b = (b & 0xCC) >> 2 | (b & 0x33) << 2; b = (b & 0xAA) >> 1 | (b & 0x55) << 1; return (unsigned long int)b; }