SHIVA T / Mbed 2 deprecated Color Sensor

this is a small prototype for color sensor, which can detect three colors... this was made by using an LDR,1.5 K resistor and the wiz wiki 7500 board

Dependencies:   mbed

Fork of ADC_test by Simon Blandford

the things you need for this are wiznet board or any other micro controller can do it when you understand the logic i have applied here.An LDR and one resistor for your reference i have used 1.5K resistor in my work.

connect the LDR and resistor in series in between the 3.3V and GND of the board.take outpt from the point where LDR and resistor met.

it's just an voltage divider circuit depends on the color you subject to LDR the resistance of LDR will vary and the volatge also does the same.

then feed the output on the adc pin of micro controller, then you will get various values for various colors. the adc which i have used is 12 bit one that's why it's having 4096 count. you have to change the values in the program according to your adc count.

sorry for my bad english.........

ADC_full/adc.cpp

Committer:
simonb
Date:
2010-02-10
Revision:
0:a2562dfbf543

File content as of revision 0:a2562dfbf543:

/* mbed Library - ADC
 * Copyright (c) 2010, sblandford
 * released under MIT license http://mbed.org/licence/mit
 */
#include "mbed.h"
#include "adc.h"


ADC *ADC::instance;

ADC::ADC(int sample_rate, int cclk_div)
    {

    int i, adc_clk_freq, pclk, clock_div, max_div=1;

    //Work out CCLK
    adc_clk_freq=CLKS_PER_SAMPLE*sample_rate;
    int m = (LPC_SC->PLL0CFG & 0xFFFF) + 1;
    int n = (LPC_SC->PLL0CFG >> 16) + 1;
    int cclkdiv = LPC_SC->CCLKCFG + 1;
    int Fcco = (2 * m * XTAL_FREQ) / n;
    int cclk = Fcco / cclkdiv;

    //Power up the ADC        
    LPC_SC->PCONP |= (1 << 12);
    //Set clock at cclk / 1.
    LPC_SC->PCLKSEL0 &= ~(0x3 << 24);    
    switch (cclk_div) {
        case 1:
            LPC_SC->PCLKSEL0 |= 0x1 << 24;
            break;
        case 2:
            LPC_SC->PCLKSEL0 |= 0x2 << 24;
            break;
        case 4:
            LPC_SC->PCLKSEL0 |= 0x0 << 24;
            break;
        case 8:
            LPC_SC->PCLKSEL0 |= 0x3 << 24;
            break;
        default:
            fprintf(stderr, "Warning: ADC CCLK clock divider must be 1, 2, 4 or 8. %u supplied.\n",
                cclk_div);
            fprintf(stderr, "Defaulting to 1.\n");
            LPC_SC->PCLKSEL0 |= 0x1 << 24;
            break;
    }
    pclk = cclk / cclk_div;
    clock_div=pclk / adc_clk_freq;

    if (clock_div > 0xFF) {
        fprintf(stderr, "Warning: Clock division is %u which is above 255 limit. Re-Setting at limit.\n",
            clock_div);
        clock_div=0xFF;
    }
    if (clock_div == 0) {
        fprintf(stderr, "Warning: Clock division is 0. Re-Setting to 1.\n");
        clock_div=1;
    }

    _adc_clk_freq=pclk / clock_div;
    if (_adc_clk_freq > MAX_ADC_CLOCK) {
        fprintf(stderr, "Warning: Actual ADC sample rate of %u which is above %u limit\n",
            _adc_clk_freq / CLKS_PER_SAMPLE, MAX_ADC_CLOCK / CLKS_PER_SAMPLE);
        while ((pclk / max_div) > MAX_ADC_CLOCK) max_div++;
        fprintf(stderr, "Maximum recommended sample rate is %u\n", (pclk / max_div) / CLKS_PER_SAMPLE);
    }

    LPC_ADC->ADCR =
        ((clock_div - 1 ) << 8 ) |    //Clkdiv
        ( 1 << 21 );                  //A/D operational

    //Default no channels enabled
    LPC_ADC->ADCR &= ~0xFF;
    //Default NULL global custom isr
    _adc_g_isr = NULL;
    //Initialize arrays
    for (i=7; i>=0; i--) {
        _adc_data[i] = 0;
        _adc_isr[i] = NULL;
    }


    //* Attach IRQ
    instance = this;
    NVIC_SetVector(ADC_IRQn, (uint32_t)&_adcisr);

    //Disable global interrupt
    LPC_ADC->ADINTEN &= ~0x100;

};

void ADC::_adcisr(void)
{
    instance->adcisr();
}


void ADC::adcisr(void)  
{
    uint32_t stat;
    int chan;

    // Read status
    stat = LPC_ADC->ADSTAT;
    //Scan channels for over-run or done and update array
    if (stat & 0x0101) _adc_data[0] = LPC_ADC->ADDR0;
    if (stat & 0x0202) _adc_data[1] = LPC_ADC->ADDR1;
    if (stat & 0x0404) _adc_data[2] = LPC_ADC->ADDR2;
    if (stat & 0x0808) _adc_data[3] = LPC_ADC->ADDR3;
    if (stat & 0x1010) _adc_data[4] = LPC_ADC->ADDR4;
    if (stat & 0x2020) _adc_data[5] = LPC_ADC->ADDR5;
    if (stat & 0x4040) _adc_data[6] = LPC_ADC->ADDR6;
    if (stat & 0x8080) _adc_data[7] = LPC_ADC->ADDR7;

    // Channel that triggered interrupt
    chan = (LPC_ADC->ADGDR >> 24) & 0x07;
    //User defined interrupt handlers
    if (_adc_isr[chan] != NULL)
        _adc_isr[chan](_adc_data[chan]);
    if (_adc_g_isr != NULL)
        _adc_g_isr(chan, _adc_data[chan]); 
    return;
}

int ADC::_pin_to_channel(PinName pin) {
    int chan;
    switch (pin) {
        case p15://=p0.23 of LPC1768
        default:
            chan=0;
            break;
        case p16://=p0.24 of LPC1768
            chan=1;
            break;
        case p17://=p0.25 of LPC1768
            chan=2;
            break;
        case p18://=p0.26 of LPC1768
            chan=3;
            break;
        case p19://=p1.30 of LPC1768
            chan=4;
            break;
        case p20://=p1.31 of LPC1768
            chan=5;
            break;
    }
    return(chan);
}

PinName ADC::channel_to_pin(int chan) {
    const PinName pin[8]={p15, p16, p17, p18, p19, p20, p15, p15};
    
    if ((chan < 0) || (chan > 5))
        fprintf(stderr, "ADC channel %u is outside range available to MBED pins.\n", chan);
    return(pin[chan & 0x07]);
} 


int ADC::channel_to_pin_number(int chan) {
    const int pin[8]={15, 16, 17, 18, 19, 20, 0, 0};
    
    if ((chan < 0) || (chan > 5))
        fprintf(stderr, "ADC channel %u is outside range available to MBED pins.\n", chan);
    return(pin[chan & 0x07]);
} 


uint32_t ADC::_data_of_pin(PinName pin) {
    //If in burst mode and at least one interrupt enabled then
    //take all values from _adc_data
    if (burst() && (LPC_ADC->ADINTEN & 0x3F)) {
        return(_adc_data[_pin_to_channel(pin)]);
    } else {
        //Return current register value or last value from interrupt
        switch (pin) {
            case p15://=p0.23 of LPC1768
            default:
                return(LPC_ADC->ADINTEN & 0x01?_adc_data[0]:LPC_ADC->ADDR0);
            case p16://=p0.24 of LPC1768
                return(LPC_ADC->ADINTEN & 0x02?_adc_data[1]:LPC_ADC->ADDR1);
            case p17://=p0.25 of LPC1768
                return(LPC_ADC->ADINTEN & 0x04?_adc_data[2]:LPC_ADC->ADDR2);
            case p18://=p0.26 of LPC1768:
                return(LPC_ADC->ADINTEN & 0x08?_adc_data[3]:LPC_ADC->ADDR3);
            case p19://=p1.30 of LPC1768
                return(LPC_ADC->ADINTEN & 0x10?_adc_data[4]:LPC_ADC->ADDR4);
            case p20://=p1.31 of LPC1768
                return(LPC_ADC->ADINTEN & 0x20?_adc_data[5]:LPC_ADC->ADDR5);
        }
    }
}

//Enable or disable an ADC pin
void ADC::setup(PinName pin, int state) {
    int chan;    
    chan=_pin_to_channel(pin);
    if ((state & 1) == 1) {
        switch(pin) {
            case p15://=p0.23 of LPC1768
            default:
                LPC_PINCON->PINSEL1 &= ~((unsigned int)0x3 << 14);
                LPC_PINCON->PINSEL1 |= (unsigned int)0x1 << 14;
                LPC_PINCON->PINMODE1 &= ~((unsigned int)0x3 << 14);
                LPC_PINCON->PINMODE1 |= (unsigned int)0x2 << 14;
                break;
            case p16://=p0.24 of LPC1768
                LPC_PINCON->PINSEL1 &= ~((unsigned int)0x3 << 16);
                LPC_PINCON->PINSEL1 |= (unsigned int)0x1 << 16;
                LPC_PINCON->PINMODE1 &= ~((unsigned int)0x3 << 16);
                LPC_PINCON->PINMODE1 |= (unsigned int)0x2 << 16;
                break;
            case p17://=p0.25 of LPC1768
                LPC_PINCON->PINSEL1 &= ~((unsigned int)0x3 << 18);
                LPC_PINCON->PINSEL1 |= (unsigned int)0x1 << 18;
                LPC_PINCON->PINMODE1 &= ~((unsigned int)0x3 << 18);
                LPC_PINCON->PINMODE1 |= (unsigned int)0x2 << 18;
                break;
            case p18://=p0.26 of LPC1768:
                LPC_PINCON->PINSEL1 &= ~((unsigned int)0x3 << 20);
                LPC_PINCON->PINSEL1 |= (unsigned int)0x1 << 20;
                LPC_PINCON->PINMODE1 &= ~((unsigned int)0x3 << 20);
                LPC_PINCON->PINMODE1 |= (unsigned int)0x2 << 20;
                break;
            case p19://=p1.30 of LPC1768
                LPC_PINCON->PINSEL3 &= ~((unsigned int)0x3 << 28);
                LPC_PINCON->PINSEL3 |= (unsigned int)0x3 << 28;
                LPC_PINCON->PINMODE3 &= ~((unsigned int)0x3 << 28);
                LPC_PINCON->PINMODE3 |= (unsigned int)0x2 << 28;
                break;
            case p20://=p1.31 of LPC1768
                LPC_PINCON->PINSEL3 &= ~((unsigned int)0x3 << 30);
                LPC_PINCON->PINSEL3 |= (unsigned int)0x3 << 30;
                LPC_PINCON->PINMODE3 &= ~((unsigned int)0x3 << 30);
                LPC_PINCON->PINMODE3 |= (unsigned int)0x2 << 30;
               break;
        }
        //Only one channel can be selected at a time if not in burst mode
        if (!burst()) LPC_ADC->ADCR &= ~0xFF;
        //Select channel
        LPC_ADC->ADCR |= (1 << chan);
    }
    else {
        switch(pin) {
            case p15://=p0.23 of LPC1768
            default:
                LPC_PINCON->PINSEL1 &= ~((unsigned int)0x3 << 14);
                LPC_PINCON->PINMODE1 &= ~((unsigned int)0x3 << 14);
                break;
            case p16://=p0.24 of LPC1768
                LPC_PINCON->PINSEL1 &= ~((unsigned int)0x3 << 16);
                LPC_PINCON->PINMODE1 &= ~((unsigned int)0x3 << 16);
                break;
            case p17://=p0.25 of LPC1768
                LPC_PINCON->PINSEL1 &= ~((unsigned int)0x3 << 18);
                LPC_PINCON->PINMODE1 &= ~((unsigned int)0x3 << 18);
                break;
            case p18://=p0.26 of LPC1768:
                LPC_PINCON->PINSEL1 &= ~((unsigned int)0x3 << 20);
                LPC_PINCON->PINMODE1 &= ~((unsigned int)0x3 << 20);
                break;
            case p19://=p1.30 of LPC1768
                LPC_PINCON->PINSEL3 &= ~((unsigned int)0x3 << 28);
                LPC_PINCON->PINMODE3 &= ~((unsigned int)0x3 << 28);
                break;
            case p20://=p1.31 of LPC1768
                LPC_PINCON->PINSEL3 &= ~((unsigned int)0x3 << 30);
                LPC_PINCON->PINMODE3 &= ~((unsigned int)0x3 << 30);
                break;
        }
        LPC_ADC->ADCR &= ~(1 << chan);
    }
}
//Return channel enabled/disabled state
int ADC::setup(PinName pin) {
    int chan;
    
    chan = _pin_to_channel(pin);
    return((LPC_ADC->ADCR & (1 << chan)) >> chan);
}

//Select channel already setup
void ADC::select(PinName pin) {
    int chan;
    
    //Only one channel can be selected at a time if not in burst mode
    if (!burst()) LPC_ADC->ADCR &= ~0xFF;
    //Select channel
    chan = _pin_to_channel(pin);
    LPC_ADC->ADCR |= (1 << chan);
}

//Enable or disable burst mode
void ADC::burst(int state) {
    if ((state & 1) == 1) {
        if (startmode(0) != 0)
            fprintf(stderr, "Warning. startmode is %u. Must be 0 for burst mode.\n", startmode(0));
        LPC_ADC->ADCR |= (1 << 16);
    }
    else 
        LPC_ADC->ADCR &= ~(1 << 16);
}
//Return burst mode state
int  ADC::burst(void) {
    return((LPC_ADC->ADCR & (1 << 16)) >> 16);
}

//Set startmode and edge
void ADC::startmode(int mode, int edge) {
    int lpc_adc_temp;
    
    //Reset start mode and edge bit, 
    lpc_adc_temp = LPC_ADC->ADCR & ~(0x0F << 24);
    //Write with new values
    lpc_adc_temp |= ((mode & 7) << 24) | ((edge & 1) << 27);
    LPC_ADC->ADCR = lpc_adc_temp;
}

//Return startmode state according to mode_edge=0: mode and mode_edge=1: edge
int ADC::startmode(int mode_edge){
    switch (mode_edge) {
        case 0:
        default:
            return((LPC_ADC->ADCR >> 24) & 0x07);
        case 1:
            return((LPC_ADC->ADCR >> 27) & 0x01);
    }
}

//Start ADC conversion
void ADC::start(void) {
    startmode(1,0);
}


//Set interrupt enable/disable for pin to state
void ADC::interrupt_state(PinName pin, int state) {
    int chan;
    
    chan = _pin_to_channel(pin);
    if (state == 1) {
        LPC_ADC->ADINTEN &= ~0x100;
        LPC_ADC->ADINTEN |= 1 << chan;
        /* Enable the ADC Interrupt */
        NVIC_EnableIRQ(ADC_IRQn);
    } else {
        LPC_ADC->ADINTEN &= ~( 1 << chan );
        //Disable interrrupt if no active pins left
        if ((LPC_ADC->ADINTEN & 0xFF) == 0)
            NVIC_DisableIRQ(ADC_IRQn);
    }
}

//Return enable/disable state of interrupt for pin
int ADC::interrupt_state(PinName pin) {
    int chan;
        
    chan = _pin_to_channel(pin);
    return((LPC_ADC->ADINTEN >> chan) & 0x01);
}


//Attach custom interrupt handler replacing default
void ADC::attach(void(*fptr)(void)) {
    //* Attach IRQ
    NVIC_SetVector(ADC_IRQn, (uint32_t)fptr);
}

//Restore default interrupt handler
void ADC::detach(void) {
    //* Attach IRQ
    instance = this;
    NVIC_SetVector(ADC_IRQn, (uint32_t)&_adcisr);
}


//Append interrupt handler for pin to function isr
void ADC::append(PinName pin, void(*fptr)(uint32_t value)) {
    int chan;
        
    chan = _pin_to_channel(pin);
    _adc_isr[chan] = fptr;
}

//Append interrupt handler for pin to function isr
void ADC::unappend(PinName pin) {
    int chan;
        
    chan = _pin_to_channel(pin);
    _adc_isr[chan] = NULL;
}

//Unappend global interrupt handler to function isr
void ADC::append(void(*fptr)(int chan, uint32_t value)) {
    _adc_g_isr = fptr;
}

//Detach global interrupt handler to function isr
void ADC::unappend() {
    _adc_g_isr = NULL;
}

//Set ADC offset
void offset(int offset) {
    LPC_ADC->ADTRM &= ~(0x07 << 4);
    LPC_ADC->ADTRM |= (offset & 0x07) << 4;
}

//Return current ADC offset
int offset(void) {
    return((LPC_ADC->ADTRM >> 4) & 0x07);
}

//Return value of ADC on pin
int ADC::read(PinName pin) {
    //Reset DONE and OVERRUN flags of interrupt handled ADC data
    _adc_data[_pin_to_channel(pin)] &= ~(((uint32_t)0x01 << 31) | ((uint32_t)0x01 << 30));
    //Return value
    return((_data_of_pin(pin) >> 4) & 0xFFF);
}

//Return DONE flag of ADC on pin
int ADC::done(PinName pin) {
    return((_data_of_pin(pin) >> 31) & 0x01);
}

//Return OVERRUN flag of ADC on pin
int ADC::overrun(PinName pin) {
    return((_data_of_pin(pin) >> 30) & 0x01);
}

int ADC::actual_adc_clock(void) {
    return(_adc_clk_freq);
}

int ADC::actual_sample_rate(void) {
    return(_adc_clk_freq / CLKS_PER_SAMPLE);
}