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Adding code example for i2c LCD display
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@Rubberazer
Rubberazer committed Nov 4, 2023
1 parent ccf069c commit 264cefe
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Showing 2 changed files with 59 additions and 79 deletions.
70 changes: 30 additions & 40 deletions EXAMPLES_C++/lcd_i2c.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -5,69 +5,61 @@

#include <iostream>
#include <unistd.h>
#include <string.h>
#include <cstring>
#include <jetgpio.h>

// Global variable to interrupt the loop later on
static volatile int interrupt = 1;

// Ctrl-c signal function handler
void inthandler(int signum)
{
usleep(1000);
printf("\nCaught Ctrl-c, coming out ...\n");
interrupt = 0;
}

void send_command(unsigned handle, unsigned i2cAddr, unsigned command){
unsigned buffer = command & 0xF0;
buffer |= 0x04;
unsigned buffer2 = buffer;
buffer |= 0x08;
i2cWriteByteData(handle, i2cAddr, buffer, buffer);
i2cWriteByteData(handle, i2cAddr, buffer, 0x0);
usleep(2000);
buffer2 &= 0xFB;
i2cWriteByteData(handle, i2cAddr, buffer2, buffer2);
buffer2 |= 0x08;
i2cWriteByteData(handle, i2cAddr, buffer2, 0x0);

buffer = (command & 0x0F) << 4;
buffer |= 0x04;
buffer2 = buffer;
buffer |= 0x08;
i2cWriteByteData(handle, i2cAddr, buffer, buffer);
i2cWriteByteData(handle, i2cAddr, buffer, 0x0);
usleep(2000);
buffer2 &= 0xFB;
i2cWriteByteData(handle, i2cAddr, buffer2, buffer2);
buffer2 |= 0x08;
i2cWriteByteData(handle, i2cAddr, buffer2, 0x0);
}

void send_data(unsigned handle, unsigned i2cAddr, unsigned data){
unsigned buffer = data & 0xF0;
buffer |= 0x05;
//unsigned buffer2 = buffer;
unsigned buffer2 = buffer;
buffer |= 0x08;
i2cWriteByteData(handle, i2cAddr, buffer, 0);
usleep(2000);
//buffer2 &= 0xFB;
//i2cWriteByteData(handle, i2cAddr, buffer2, buffer2);
//i2cWriteByteData(handle, i2cAddr, buffer, 0);
//usleep(2000);
buffer2 &= 0xFB;
buffer2 |= 0x08;
i2cWriteByteData(handle, i2cAddr, buffer, buffer2);

buffer = (data & 0x0F) << 4;
buffer |= 0x05;
//buffer2 = buffer;
buffer2 = buffer;
buffer |= 0x08;
i2cWriteByteData(handle, i2cAddr, buffer, 0);
usleep(2000);
//buffer2 &= 0xFB;
//i2cWriteByteData(handle, i2cAddr, buffer2, buffer2);
//i2cWriteByteData(handle, i2cAddr, buffer, 0);
//usleep(2000);
buffer2 &= 0xFB;
buffer2 |= 0x08;
i2cWriteByteData(handle, i2cAddr, buffer, buffer2);
}

int main(int argc, char *argv[]){

const int LCD_SLAVE_ADDRESS = 0x3f;

printf("Press Ctrl-c to stop...\n");
printf("This will print something on the LCD and it will stay until LCD reset\n");

gpioInitialise();


// Opening the connection to the LCD I2C slave 0x3f, i2c port 0 (pins 27/28), flags = 0 (100 kHz)

int lcd = i2cOpen(0,0);
Expand Down Expand Up @@ -95,26 +87,24 @@ int main(int argc, char *argv[]){

usleep(5000);

i2cWriteByteData(lcd, LCD_SLAVE_ADDRESS, 0x08, 0x08);
i2cWriteByteData(lcd, LCD_SLAVE_ADDRESS, 0x08, 0x0);

//Now can start writing to the lcd screen, starting at position 0,0 first line ot the left

char message[15] = {"Jetgpio"};
char message2[15] = {"by Rubberazer"};

while(interrupt){
send_command(lcd, LCD_SLAVE_ADDRESS, 0x80); //Positioning cursor at point 0,0
for (size_t i=0;i<strlen(message);i++){
send_data(lcd, LCD_SLAVE_ADDRESS, (unsigned)message[i]);
}

send_command(lcd, LCD_SLAVE_ADDRESS, 0x80); //Positioning cursor at point 0,0
for (size_t i=0;i<strlen(message);i++){
send_data(lcd, LCD_SLAVE_ADDRESS, (unsigned)message[i]);
}

send_command(lcd, LCD_SLAVE_ADDRESS, 0xC1); //Positioning cursor at second line
for (size_t i=0;i<strlen(message2);i++){
send_data(lcd, LCD_SLAVE_ADDRESS, (unsigned)message2[i]);
}
send_command(lcd, LCD_SLAVE_ADDRESS, 0xC1); //Positioning cursor at second line
for (size_t i=0;i<strlen(message2);i++){
send_data(lcd, LCD_SLAVE_ADDRESS, (unsigned)message2[i]);
}
send_command(lcd, LCD_SLAVE_ADDRESS, 0x01); //Clear screen


// Closing i2c connection

i2cClose(lcd);
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68 changes: 29 additions & 39 deletions EXAMPLES_C/lcd_i2c.c
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Original file line number Diff line number Diff line change
Expand Up @@ -10,66 +10,58 @@
#include <string.h>
#include <jetgpio.h>

// Global variable to interrupt the loop later on
static volatile int interrupt = 1;

// Ctrl-c signal function handler
void inthandler(int signum)
{
usleep(1000);
printf("\nCaught Ctrl-c, coming out ...\n");
interrupt = 0;
}

void send_command(unsigned handle, unsigned i2cAddr, unsigned command){
unsigned buffer = command & 0xF0;
buffer |= 0x04;
unsigned buffer2 = buffer;
buffer |= 0x08;
i2cWriteByteData(handle, i2cAddr, buffer, buffer);
i2cWriteByteData(handle, i2cAddr, buffer, 0x0);
usleep(2000);
buffer2 &= 0xFB;
i2cWriteByteData(handle, i2cAddr, buffer2, buffer2);
buffer2 |= 0x08;
i2cWriteByteData(handle, i2cAddr, buffer2, 0x0);

buffer = (command & 0x0F) << 4;
buffer |= 0x04;
buffer2 = buffer;
buffer |= 0x08;
i2cWriteByteData(handle, i2cAddr, buffer, buffer);
i2cWriteByteData(handle, i2cAddr, buffer, 0x0);
usleep(2000);
buffer2 &= 0xFB;
i2cWriteByteData(handle, i2cAddr, buffer2, buffer2);
buffer2 |= 0x08;
i2cWriteByteData(handle, i2cAddr, buffer2, 0x0);
}

void send_data(unsigned handle, unsigned i2cAddr, unsigned data){
unsigned buffer = data & 0xF0;
buffer |= 0x05;
//unsigned buffer2 = buffer;
unsigned buffer2 = buffer;
buffer |= 0x08;
i2cWriteByteData(handle, i2cAddr, buffer, 0);
usleep(2000);
//buffer2 &= 0xFB;
//i2cWriteByteData(handle, i2cAddr, buffer2, buffer2);
//i2cWriteByteData(handle, i2cAddr, buffer, 0);
//usleep(2000);
buffer2 &= 0xFB;
buffer2 |= 0x08;
i2cWriteByteData(handle, i2cAddr, buffer, buffer2);

buffer = (data & 0x0F) << 4;
buffer |= 0x05;
//buffer2 = buffer;
buffer2 = buffer;
buffer |= 0x08;
i2cWriteByteData(handle, i2cAddr, buffer, 0);
usleep(2000);
//buffer2 &= 0xFB;
//i2cWriteByteData(handle, i2cAddr, buffer2, buffer2);
//i2cWriteByteData(handle, i2cAddr, buffer, 0);
//usleep(2000);
buffer2 &= 0xFB;
buffer2 |= 0x08;
i2cWriteByteData(handle, i2cAddr, buffer, buffer2);
}

int main(int argc, char *argv[]){

const int LCD_SLAVE_ADDRESS = 0x3f;

printf("Press Ctrl-c to stop...\n");
printf("This will print something on the LCD and it will stay until LCD reset\n");

gpioInitialise();


// Opening the connection to the LCD I2C slave 0x3f, i2c port 0 (pins 27/28), flags = 0 (100 kHz)

int lcd = i2cOpen(0,0);
Expand Down Expand Up @@ -97,26 +89,24 @@ int main(int argc, char *argv[]){

usleep(5000);

i2cWriteByteData(lcd, LCD_SLAVE_ADDRESS, 0x08, 0x08);
i2cWriteByteData(lcd, LCD_SLAVE_ADDRESS, 0x08, 0x0);

//Now can start writing to the lcd screen, starting at position 0,0 first line ot the left

char message[15] = {"Jetgpio"};
char message2[15] = {"by Rubberazer"};

while(interrupt){
send_command(lcd, LCD_SLAVE_ADDRESS, 0x80); //Positioning cursor at point 0,0
for (int i=0;i<strlen(message);i++){
send_data(lcd, LCD_SLAVE_ADDRESS, (unsigned)message[i]);
}

send_command(lcd, LCD_SLAVE_ADDRESS, 0x80); //Positioning cursor at point 0,0
for (int i=0;i<strlen(message);i++){
send_data(lcd, LCD_SLAVE_ADDRESS, (unsigned)message[i]);
}

send_command(lcd, LCD_SLAVE_ADDRESS, 0xC1); //Positioning cursor at second line
for (int i=0;i<strlen(message2);i++){
send_data(lcd, LCD_SLAVE_ADDRESS, (unsigned)message2[i]);
}
send_command(lcd, LCD_SLAVE_ADDRESS, 0xC1); //Positioning cursor at second line
for (int i=0;i<strlen(message2);i++){
send_data(lcd, LCD_SLAVE_ADDRESS, (unsigned)message2[i]);
}
send_command(lcd, LCD_SLAVE_ADDRESS, 0x01); //Clear screen


// Closing i2c connection

i2cClose(lcd);
Expand Down

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