main.cpp

00001 
00002 #define SAMPLE_RATE    150000
00003 
00004 #include "mbed.h"
00005 #include "adc.h"
00006 
00007 DigitalOut int_led(LED1);
00008 
00009 //Initialise ADC to maximum SAMPLE_RATE and cclk divide set to 1
00010 ADC adc(SAMPLE_RATE, 1);
00011 
00012 //Toggle LED on interrupt
00013 void led_toggle(int chan, uint32_t value) {
00014     int_led = !int_led;
00015 }
00016 
00017 //Report ADC value on interrupt
00018 void print_value(int chan, uint32_t value) {
00019     printf("ADC interrupt on pin %u, value=%04u.\n", 
00020         adc.channel_to_pin_number(chan), (value >> 4) & 0xFFF);
00021 }
00022 
00023 
00024 int main() {
00025     int i;
00026     
00027     printf("Requested max sample rate is %u, actual max sample rate is %u.\n",
00028         SAMPLE_RATE, adc.actual_sample_rate());
00029     while (1) {
00030     
00031         //Set up ADC on pin 20
00032         adc.setup(p20,1);
00033         //Set up ADC on pin 19
00034         adc.setup(p19,1);
00035         wait(1);
00036         
00037         //Measure pin 20
00038         adc.select(p20);
00039         //Start ADC conversion
00040         adc.start();
00041         //Wait for it to complete
00042         while(!adc.done(p20));
00043         printf("Measured value on pin 20 is %04u.\n", adc.read(p20));
00044         wait(1);
00045 
00046         //Measure pin 19
00047         adc.select(p19);
00048         //Start ADC conversion
00049         adc.start();
00050         //Wait for it to complete
00051         while(!adc.done(p19));
00052         printf("Measured value on pin 19 is %04u.\n", adc.read(p19));
00053         wait(1);
00054 
00055     
00056         //Append an interrupt handler that prints the channel and value
00057         adc.append(print_value);
00058         //Measure pin 20
00059         adc.select(p20);
00060         //Enable the interrupt
00061         adc.interrupt_state(p20,1);
00062         //Start ADC conversion
00063         adc.start();
00064         //Wait for it to complete
00065         while(!adc.done(p20));
00066         wait(1);
00067     
00068         //Unset pin 20
00069         adc.setup(p20,0);
00070     
00071         //Togle LED on each converstion.
00072         //Should be 12.5KHz on LED for all 6 pins.
00073         //Sample rate=150KHz / 6 channels / 2
00074         adc.append(led_toggle);
00075     
00076         //Prepare for burst mode on all ADC pins
00077         adc.startmode(0,0);
00078         adc.burst(1);
00079         adc.setup(p20,1);
00080         adc.setup(p19,1);
00081         adc.setup(p18,1);
00082         adc.setup(p17,1);
00083         adc.setup(p16,1);
00084         adc.setup(p15,1);
00085         //For burst mode, only one interrupt is required
00086         //which can be on any enabled pin. We have enabled all
00087         //of them here.
00088         adc.interrupt_state(p15,1);
00089         printf("Burst mode, printing once per second...\n");
00090         for (i=0; i<5; i++)
00091         {
00092             printf("%04u %04u %04u %04u %04u %04u\n", 
00093                 adc.read(p20),
00094                 adc.read(p19),
00095                 adc.read(p18),
00096                 adc.read(p17),
00097                 adc.read(p16),
00098                 adc.read(p15));
00099             wait(1);
00100         }
00101         adc.burst(0);
00102         adc.setup(p20,0);
00103         adc.setup(p19,0);
00104         adc.setup(p18,0);
00105         adc.setup(p17,0);
00106         adc.setup(p16,0);
00107         adc.setup(p15,0);
00108         adc.interrupt_state(p20,0);
00109         adc.interrupt_state(p19,0);
00110         adc.interrupt_state(p18,0);
00111         adc.interrupt_state(p17,0);
00112         adc.interrupt_state(p16,0);
00113         adc.interrupt_state(p15,0);
00114         
00115         printf("\n");
00116     }
00117 }