Hello,
I am developing a code with msp430f5438a. The code consists in an adquisition of a voltage by the ADC12 and this value is transmit from the UART port to the computer.
The problem is the ADC12 only reads a random value and when you change the voltage at this port, the value at ADC12 not change.
I attach the code for more information:
#include <msp430.h>
#include <stdlib.h>
////////////////////////////////////////////////////////////////////////////////////////
///// Defines /////
////////////////////////////////////////////////////////////////////////////////////////
#define MAX_SIZE 0xff //int equivale a 2 bytes --> 256 bytes
////////////////////////////////////////////////////////////////////////////////////////
///// User's functions /////
////////////////////////////////////////////////////////////////////////////////////////
void ADC_CONF (void)
{
//ADC12 configuration
P6SEL |= 0x80; // P6.7 ADC option select
ADC12CTL0 = ADC12SHT02 + ADC12ON; // Sampling time, ADC12 on
ADC12CTL1 = ADC12SHP; // Use sampling timer
ADC12IE = 0x01; // Enable interrupt
ADC12MCTL0 |= ADC12INCH_7;
ADC12CTL0 |= ADC12ENC;
}
void UART_CONF (void)
{
//UART configuration
P3SEL = 0x30; // P3.4,5 = USCI_A0 TXD/RXD
UCA0CTL1 |= UCSWRST; // **Put state machine in reset**
UCA0CTL1 |= UCSSEL_2; // SMCLK
UCA0BR0 = 6; // 1MHz 9600 (see User's Guide)
UCA0BR1 = 0; // 1MHz 9600
UCA0MCTL = UCBRS_0 + UCBRF_13 + UCOS16; // Modln UCBRSx=0, UCBRFx=0,
// over sampling
UCA0CTL1 &= ~UCSWRST; // **Initialize USCI state machine**
}
void uartSend (unsigned char *pucData, unsigned char ucLength)
{
while(ucLength--)
{
// Wait for TX buffer to be ready for new data
while(!(UCA1IFG & UCTXIFG));
// Push data to TX buffer
UCA0TXBUF = *pucData;
// Update variables
ucLength--;
pucData++;
}
// Wait until the last byte is completely sent
while(UCA0STAT & UCBUSY);
}
void store_buffer (unsigned char *buffer, unsigned char length, unsigned int value)
{
while(length--)
{
*buffer=value;
length--;
buffer++;
}
}
////////////////////////////////////////////////////////////////////////////////////////
///// Variables declaration /////
////////////////////////////////////////////////////////////////////////////////////////
int ADC_IN=0;
unsigned int UART_OUT=0;
unsigned int i=0;
unsigned char t=0;
unsigned char *buffer1;
//unsigned int *buffer2;
////////////////////////////////////////////////////////////////////////////////////////
///// Main Program /////
////////////////////////////////////////////////////////////////////////////////////////
int main(void)
{
WDTCTL = WDTPW + WDTHOLD; // Stop WDT
ADC_CONF ();
UART_CONF();
buffer1= (unsigned char*) malloc (MAX_SIZE * sizeof (unsigned char)); //256bytes reserved for buffer1
// buffer2= (unsigned int*) malloc (MAX_SIZE * sizeof (unsigned int)); //256bytes reserved for buffer2
// Pin configuration
P1DIR |= BIT0; // P1.0 output
// __delay_cycles(10000);
while (1)
{
ADC12CTL0 |= ADC12SC; // Start sampling/conversion
__bis_SR_register(LPM0_bits + GIE); // LPM0, ADC12_ISR will force exit
__no_operation(); // For debugger
}
}
////////////////////////////////////////////////////////////////////////////////////////
///// Interrupts /////
////////////////////////////////////////////////////////////////////////////////////////
#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,34))
{
case 0: break; // Vector 0: No interrupt
case 2: break; // Vector 2: ADC overflow
case 4: break; // Vector 4: ADC timing overflow
case 6: // Vector 6: ADC12IFG0
ADC_IN = ADC12MEM0;
UART_OUT=ADC_IN/16;
store_buffer (buffer1, MAX_SIZE, UART_OUT);
uartSend (buffer1, MAX_SIZE);
__bic_SR_register_on_exit(LPM0_bits); // Exit active CPU
break;
case 8: break; // Vector 8: ADC12IFG1
case 10: break; // Vector 10: ADC12IFG2
case 12: break; // Vector 12: ADC12IFG3
case 14: break; // Vector 14: ADC12IFG4
case 16: break; // Vector 16: ADC12IFG5
case 18: break; // Vector 18: ADC12IFG6
case 20: // Vector 20: ADC12IFG7
break;
case 22: break; // Vector 22: ADC12IFG8
case 24: break; // Vector 24: ADC12IFG9
case 26: break; // Vector 26: ADC12IFG10
case 28: break; // Vector 28: ADC12IFG11
case 30: break; // Vector 30: ADC12IFG12
case 32: break; // Vector 32: ADC12IFG13
case 34: break; // Vector 34: ADC12IFG14
default: break;
}
}
Thanks in advance
