LaunchPad, ADC, and LCD

[RobG 1,891]

It's time to play with ADC. I put together 2 examples, single channel and sequence of channels.Both use Vcc as reference.
In the first example value of ADC10MEM register is displayed and the same value converted to show actual voltage.
In the second example, 4 inputs are sampled, values are not converted, binary data is displayed (don't get fooled by the period.)

 

#include "msp430g2231.h"

#define sendData(data) send(data, 1)
#define sendInstruction(data) send(data, 0)
#define initDisplay() sendInstruction(0x3C); sendInstruction(0x0C); clearDisplay(); sendInstruction(0x06)
#define clearDisplay() sendInstruction(0x01); _delay_cycles(2000)
#define DATAPIN BIT6
#define CLOCKPIN BIT5
#define ENABLEPIN BIT4

const char charMap[10] = {
0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,0x38,0x39
};

void send(char data, char registerSelect);
void sendDataArray(char data[], char length);

char charIndex = 0;
char bitCounter = 0;

char charsToSend[5] = {0,0,0,0,0};

void main(void) {
WDTCTL = WDTPW + WDTHOLD;

BCSCTL1 = CALBC1_1MHZ;
DCOCTL = CALDCO_1MHZ;

_delay_cycles(100000);

P1OUT &= ~(CLOCKPIN + DATAPIN);
P1OUT |= ENABLEPIN;
P1DIR |= ENABLEPIN + CLOCKPIN + DATAPIN;

initDisplay();

ADC10CTL0 = ADC10SHT_2 + ADC10ON + ADC10IE;
ADC10CTL1 = INCH_1;
ADC10AE0 |= BIT1;

CCTL0 = CCIE;
CCR0 = 12500;
TACTL = TASSEL_2 + MC_1 + ID_3;

_bis_SR_register(LPM0_bits + GIE);
}

// ADC10 interrupt service routine
#pragma vector=ADC10_VECTOR
__interrupt void ADC10_ISR(void) {
clearDisplay();

charIndex = 0;
while(charIndex < 4) {
charsToSend[charIndex] = charMap[0];
charIndex++;
}

unsigned int binary = ADC10MEM;

charIndex = 3;
while(binary > 0) {
charsToSend[charIndex] = charMap[binary % 10];
binary /= 10;
charIndex--;
}
sendDataArray(charsToSend, 4);


charIndex = 0;
while(charIndex < 5) {
charsToSend[charIndex] = charMap[0];
charIndex++;
}
charsToSend[1] = 0x2E;

binary = ADC10MEM * 3.52;

charIndex = 4;
while(binary > 0) {
charsToSend[charIndex] = charMap[binary % 10];
binary /= 10;
charIndex--;
if(charIndex == 1)
charIndex--;
}
sendInstruction(0xC0);
sendDataArray(charsToSend, 5);
sendData(0x56);
}

// Timer A0 interrupt service routine
#pragma vector = TIMERA0_VECTOR
__interrupt void Timer_A (void) {
ADC10CTL0 |= ENC + ADC10SC;
}


void sendDataArray(char data[], char length) {
charIndex = 0;
while(charIndex < length) {
sendData(data[charIndex]);
charIndex++;
}
}

void send(char data, char registerSelect) {
bitCounter = 0;
while(bitCounter < 8) {
(data & BIT7) ? (P1OUT |= DATAPIN) : (P1OUT &= ~DATAPIN);
data <<= 1;
P1OUT |= CLOCKPIN;
P1OUT &= ~CLOCKPIN;
bitCounter++;
}
registerSelect ? (P1OUT |= DATAPIN) : (P1OUT &= ~DATAPIN);
P1OUT &= ~ENABLEPIN;
P1OUT |= ENABLEPIN;
}

#include "msp430g2231.h"

#define sendData(data) send(data, 1)
#define sendInstruction(data) send(data, 0)
#define initDisplay() sendInstruction(0x3C); sendInstruction(0x0C); clearDisplay(); sendInstruction(0x06)
#define clearDisplay() sendInstruction(0x01); _delay_cycles(2000)
#define DATAPIN BIT6
#define CLOCKPIN BIT5
#define ENABLEPIN BIT4

const char charMap[10] = {
0x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,0x38,0x39
};
const char addressMap[4] = {
0x80, 0x88, 0xC0, 0xC8
};

void send(char data, char registerSelect);
void sendDataArray(char data[], char length);

char charIndex = 0;
char valueIndex = 0;
char bitCounter = 0;

char charsToSend[5] = {0,0,0,0,0};
int values[4] = {0,0,0,0};

void main(void) {
WDTCTL = WDTPW + WDTHOLD;

BCSCTL1 = CALBC1_1MHZ;
DCOCTL = CALDCO_1MHZ;

_delay_cycles(100000);

P1OUT &= ~(CLOCKPIN + DATAPIN);
P1OUT |= ENABLEPIN;
P1DIR |= ENABLEPIN + CLOCKPIN + DATAPIN;

initDisplay();

ADC10CTL1 = INCH_3 + CONSEQ_1;
ADC10CTL0 = ADC10SHT_2 + MSC + ADC10ON + ADC10IE;
ADC10DTC1 = 0x04;
ADC10AE0 |= 0x0F;

CCTL0 = CCIE;
CCR0 = 12500;
TACTL = TASSEL_2 + MC_1 + ID_3;

_bis_SR_register(LPM0_bits + GIE);
}

// ADC10 interrupt service routine
#pragma vector=ADC10_VECTOR
__interrupt void ADC10_ISR(void) {

clearDisplay();
while (ADC10CTL1 & BUSY)
;

valueIndex = 0;
while(valueIndex < 4) {

charIndex = 0;
while(charIndex < 5) {
charsToSend[charIndex] = charMap[0];
charIndex++;
}

charsToSend[1] = 0x2E;

unsigned int binary = values[valueIndex];

charIndex = 4;
while(binary > 0) {
charsToSend[charIndex] = charMap[binary % 10];
binary /= 10;
charIndex--;
if(charIndex == 1)
charIndex--;
}
sendInstruction(addressMap[valueIndex]);
sendDataArray(charsToSend, 5);
valueIndex++;
}
}

// Timer A0 interrupt service routine
#pragma vector = TIMERA0_VECTOR
__interrupt void Timer_A (void) {

ADC10CTL0 &= ~ENC;
while (ADC10CTL1 & BUSY)
;
ADC10SA = (unsigned int)&values[0];
ADC10CTL0 |= ENC + ADC10SC;
}


void sendDataArray(char data[], char length) {
charIndex = 0;
while(charIndex < length) {
sendData(data[charIndex]);
charIndex++;
}
}

void send(char data, char registerSelect) {
bitCounter = 0;
while(bitCounter < 8) {
(data & BIT7) ? (P1OUT |= DATAPIN) : (P1OUT &= ~DATAPIN);
data <<= 1;
P1OUT |= CLOCKPIN;
P1OUT &= ~CLOCKPIN;
bitCounter++;
}
registerSelect ? (P1OUT |= DATAPIN) : (P1OUT &= ~DATAPIN);
P1OUT &= ~ENABLEPIN;
P1OUT |= ENABLEPIN;
}

[bluehash 1,578]

Theis will be a good reference project for beginners.

[ttthomas 0]

Hi Robg , you havn't any schematic that comes with this ? I don't understand how yoy got the LCD working on only 3 datapins

[jsolarski 94]

its most likely a serial LCD 1 data line 2 clock pin 3 enable display

[RobG 1,891]

Hi Robg , you havn't any schematic that comes with this ? I don't understand how yoy got the LCD working on only 3 datapins

Look at this post

[Miguel23 0]

hi robG can you tell me the pins to where i can connect the LCD and also how to make it only 3 wires for the lcd. thanks 

[roadrunner84 466]

hi robG can you tell me the pins to where i can connect the LCD and also how to make it only 3 wires for the lcd. thanks 

quoting:

#define DATAPIN BIT6
#define CLOCKPIN BIT5
#define ENABLEPIN BIT4

of port 1.

 

Apparently the LCD @@RobG used is an SPI display, so you'l need an SPI display to do this, which will use 3 pins (MISO is not connected, since there is no data read from the display).

[RobG 1,891]

My LCD has SPI backpack attached.