C program in embedded Linux reads data from BMP280 temperature sensor and displays it on Adafruit1.2
Hello guys, I am trying to write a C program in embedded Linux that reads data from a BMP280 temperature sensor and displays the temperature on an Adafruit 1.3 OLED display connected via SPI. However, I am facing issues with reading data from the I2C sensor.
I Connected the BMP280 sensor to the I2C bus and verified the connection using i2cdetect.Then i Set up the OLED display on the SPI bus and verified the connection.
This is my attempt to read from the BMP280:
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/i2c-dev.h>
#define BMP280_ADDRESS 0x76
int main() {
int file;
char *filename = "/dev/i2c-1";
if ((file = open(filename, O_RDWR)) < 0) {
perror("Failed to open the i2c bus");
return 1;
}
if (ioctl(file, I2C_SLAVE, BMP280_ADDRESS) < 0) {
perror("Failed to acquire bus access and/or talk to slave");
return 1;
}
// Reading data from the BMP280
char reg[1] = {0xF7}; // Register to read from
write(file, reg, 1);
char data[8] = {0};
if (read(file, data, 8) != 8) {
perror("Failed to read from the i2c bus");
} else {
// Process the data (e.g., convert raw data to temperature)
int temp_raw = (data[3] << 12) | (data[4] << 4) | (data[5] >> 4);
// Convert temp_raw to actual temperature
// ... (calculation based on BMP280 datasheet)
printf("Temperature: %d\n", temp_raw);
}
close(file);
return 0;
}
Can someone please provide guidance or a detailed work-through on how to properly read from the BMP280 and display the temperature on the OLED screen?
I Connected the BMP280 sensor to the I2C bus and verified the connection using i2cdetect.Then i Set up the OLED display on the SPI bus and verified the connection.
This is my attempt to read from the BMP280:
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/i2c-dev.h>
#define BMP280_ADDRESS 0x76
int main() {
int file;
char *filename = "/dev/i2c-1";
if ((file = open(filename, O_RDWR)) < 0) {
perror("Failed to open the i2c bus");
return 1;
}
if (ioctl(file, I2C_SLAVE, BMP280_ADDRESS) < 0) {
perror("Failed to acquire bus access and/or talk to slave");
return 1;
}
// Reading data from the BMP280
char reg[1] = {0xF7}; // Register to read from
write(file, reg, 1);
char data[8] = {0};
if (read(file, data, 8) != 8) {
perror("Failed to read from the i2c bus");
} else {
// Process the data (e.g., convert raw data to temperature)
int temp_raw = (data[3] << 12) | (data[4] << 4) | (data[5] >> 4);
// Convert temp_raw to actual temperature
// ... (calculation based on BMP280 datasheet)
printf("Temperature: %d\n", temp_raw);
}
close(file);
return 0;
}
Can someone please provide guidance or a detailed work-through on how to properly read from the BMP280 and display the temperature on the OLED screen?
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