Hi,
I m new to coding msp. I am trying to take an analog input from an ultrasonic sensor, do an adc on it and send the output via uart to the computer so that i can see it on bray's terminal. ADC input pin is P2.0. The following is the code -
#include "msp430x22x4.h"
void main(void)
{
WDTCTL = WDTPW + WDTHOLD; // Stop WDT
ADC10CTL0 = SREF_1 + ADC10SHT_2 + REFON + ADC10ON + ADC10IE;
TACCR0 = 30; // Delay to allow Ref to settle
TACCTL0 |= CCIE; // Compare-mode interrupt.
TACTL = TASSEL_2 + MC_1; // TACLK = SMCLK, Up mode.
__bis_SR_register(CPUOFF + GIE); // LPM0, TA0_ISR will force exit
TACCTL0 &= ~CCIE; // Disable timer Interrupt
ADC10AE0 |= 0x01; // P2.0 ADC option select
P3DIR |= 0x01; // Set P3.0 to output direction
BCSCTL1 = CALBC1_1MHZ; // Set DCO
DCOCTL = CALDCO_1MHZ;
P3SEL = 0x30; // P3.4,5 = USCI_A0 TXD/RXD
UCA0CTL1 |= UCSSEL_2; // SMCLK
UCA0BR0 = 104; // 1MHz 9600
UCA0BR1 = 0; // 1MHz 9600
UCA0MCTL = UCBRS0; // Modulation UCBRSx = 1
UCA0CTL1 &= ~UCSWRST; // **Initialize USCI state machine**
IE2 |= UCA0RXIE; // Enable USCI_A0 RX interrupt
__bis_SR_register(LPM0_bits + GIE); // Enter LPM0, interrupts enabled
for (;;)
{
ADC10CTL0 |= ENC + ADC10SC; // Sampling and conversion start
__bis_SR_register(CPUOFF + GIE); // LPM0, ADC10_ISR will force exit
__interrupt void USCI0RX_ISR();
if (ADC10MEM < 0x88) // ADC10MEM = A0 > 0.2V?
P3OUT &= ~0x01; // Clear P3.0 LED off
else
P3OUT |= 0x01; // Set P3.0 LED on
}
}
// ADC10 interrupt service routine
#pragma vector=ADC10_VECTOR
__interrupt void ADC10_ISR(void)
{
__bic_SR_register_on_exit(CPUOFF); // Clear CPUOFF bit from 0(SR)
}
#pragma vector=TIMERA0_VECTOR
__interrupt void TA0_ISR(void)
{
TACTL = 0;
LPM0_EXIT; // Exit LPM0 on return
}
// Echo back RXed character, confirm TX buffer is ready first
#pragma vector=USCIAB0RX_VECTOR
__interrupt void USCI0RX_ISR(void)
{
while (!(IFG2&UCA0TXIFG)); // USCI_A0 TX buffer ready?
UCA0TXBUF = ADC10MEM; // TX -> RXed character
}
Here the adc isnt working. Please help me!!