Hi there,
I am attempting to read input from two sensors on my MSP-EXP430FR5969 Launchpad but I am having some issues with the interrupt routine. I am able to successfully read the sensor values and store them in ADC12MEM0 and ADC12MEM1, but my problem is the program never leaves the ISR and I am unable to process the data as I would like to.
Here is my code:
#include <msp430.h>
#define CONVERSION_VALUE_1_2 0.29296875 // Vref 1200mV / 4095 (12 bit ADC resolution)
unsigned int ADC_value=0;
float temp=0, light=0;
float calculate_Temp(unsigned int ADC_value);
float calculate_Light(unsigned int ADC_value);
int main(void)
{
WDTCTL = WDTPW | WDTHOLD; // Stop WDT
// GPIO Setup
P1OUT &= ~BIT0; // Clear LED to start
P1DIR |= BIT0; // P1.0 output
P1SEL1 |= BIT3 | BIT4; // Configure P1.3 and P1.4 for ADC
P1SEL0 |= BIT3 | BIT4;
// Disable the GPIO power-on default high-impedance mode to activate
// previously configured port settings
PM5CTL0 &= ~LOCKLPM5;
// By default, REFMSTR=1 => REFCTL is used to configure the internal reference
while(REFCTL0 & REFGENBUSY); // If ref generator busy, WAIT
REFCTL0 |= REFVSEL_0 | REFON; // Select internal ref = 1.2V
// Internal Reference ON
// Configure ADC12
ADC12CTL0 = ADC12SHT0_2 | ADC12ON | ADC12MSC;
ADC12CTL1 |= ADC12SHP | ADC12CONSEQ_1; // ADCCLK = MODOSC; sampling timer
ADC12CTL2 |= ADC12RES_2; // 12-bit conversion results
ADC12IER0 |= ADC12IE1; // Enable ADC conv complete interrupt
ADC12MCTL0 |= ADC12INCH_3 | ADC12VRSEL_1; // A3 ADC input select; Vref=1.2V
ADC12MCTL1 |= ADC12INCH_4 | ADC12VRSEL_1; // A4 ADC input select; Vref=1.2V
while(!(REFCTL0 & REFGENRDY)); // Wait for reference generator
// to settle
while(1)
{
__delay_cycles(5000); // Delay between conversions
ADC12CTL0 |= ADC12ENC | ADC12SC; // Sampling and conversion start
__bis_SR_register(LPM0_bits + GIE); // LPM0, ADC10_ISR will force exit
ADC_value = ADC12MEM0;
temp = calculate_Temp(ADC_value);
ADC_value = ADC12MEM1;
light = calculate_Light(ADC_value);
__no_operation(); // For debug only
}
}
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector = ADC12_VECTOR
__interrupt void ADC12_ISR(void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(ADC12_VECTOR))) ADC12_ISR (void)
#else
#error Compiler not supported!
#endif
{
switch (__even_in_range(ADC12IV, ADC12IV_ADC12RDYIFG))
{
case ADC12IV_ADC12IFG0: // Vector 12: ADC12MEM0 Interrupt
__bic_SR_register_on_exit(LPM0_bits); // Exit active CPU
case ADC12IV_ADC12IFG1: // Vector 14: ADC12MEM1 Interrupt
__bic_SR_register_on_exit(LPM0_bits); // Exit active CPU
break; // Clear CPUOFF bit from 0(SR)
default: break;
}
}
float calculate_Temp(unsigned int ADC_value){
// Retrieve voltage measurement, subtract 500mv (thermistor base @ 0C)
// Divide by 10 since thermistor reports 10mV per degree C
return ((ADC_value*CONVERSION_VALUE_1_2-500)/10);
}
float calculate_Light(unsigned int ADC_value){
// Retrieve voltage measurement for Light sensor
return (ADC_value*CONVERSION_VALUE_1_2);
}
Am I missing something inside the ISR in order to exit it? Any help would be greatly appreciated.
Thanks,
Mike
