Diff: ADC_full/adc.cpp

Revision:

0:72d0d2736b7f

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ADC_full/adc.cpp	Tue Jun 26 06:24:23 2012 +0000
@@ -0,0 +1,439 @@
+/* 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);
+}