Hello. My name is Junsuke.
Please tell us about the following events.
The result of dividing the 3.3V power supply of MSP430 by two 10kΩ was converted by ADC10.
The conversion result was 560.My calculation was 511. Why did you get the value of 560?
Below is the programming code used. Thank you.
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#include <msp430g2553.h>/* MSP430G2553用のヘッダファイル */
#include <stdint.h>/* uint8_t とか定義してあるヘッダファイル */
#include<string.h>
#include <stdio.h>
#include <stdlib.h>
char input[10];
char syokika[10]={};
int a;
int mozi;
int kai;
char mukou[64] = {'d','i','s','a','b','\0','e'};
void main(void)
{
WDTCTL = WDTPW +WDTHOLD;
BCSCTL1 = CALBC1_1MHZ;
DCOCTL = CALDCO_1MHZ;
ADC10CTL0 = ADC10SHT_2 + ADC10ON;
//ADC10CTL0 &= ~ADC10ON;
/*
ADC10SHT :ADC10のサンプル＆ホールド時間
(サンプリング・維持の時間設定?)ここでは16カウント
ADC10ON: ADC10 はオン
ADC10IE: DC10 割り込みのイネーブル
*/
ADC10CTL1 = INCH_3;
ADC10AE0 |= 0b00001000;
ADC10CTL0 |= ENC;
/*
入力チャンネルをA3に設定
ADC10 アナログ入力のイネーブル(P1.3のアナログ入力をイネーブル(P1.3がA3に対応するため)
*/
P1DIR |= 0x01;
P1OUT = 0x01;
P1SEL = 0x06;
P1SEL2 = 0x06;
UCA0CTL1 = 0b10000001;
UCA0BR0 = 0x68;
UCA0BR1 = 0x00;
UCA0MCTL = UCBRS_1;
UCA0CTL1 &= ~UCSWRST;
IE2 |= UCA0RXIE;
__bis_SR_register(LPM0_bits +GIE);
}
#pragma vector=USCIAB0RX_VECTOR
__interrupt void USCI0RX_ISR(void)
{
if(UCA0RXBUF == 'a'){
//ADC10CTL0 |= ENC;
ADC10CTL0 |= ADC10SC;
/*ENC : ADC10をイネーブル
ADC10SC: ソフトウェア制御のサンプリング / 変換の開始。*/
memset(input,'\0',sizeof(input));
snprintf(input, 10, "%d", ADC10MEM);
for(mozi=0; mozi<10; mozi++){
UCA0TXBUF = input[mozi];
while (!(IFG2 & UCA0TXIFG));
}
char kaigyo[2] = {'\r','\n'};
for(kai=0;kai<2;kai++){
UCA0TXBUF = kaigyo[kai];
__delay_cycles( 10000 );
}
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