About jbruenn

Hi @BSTRobin , thank you for your answer. To be honest: I'm flashed. I dreamed of a much simpler example. Something like: #include <unistd.h> //Needed for I2C port #include <fcntl.h> //Needed for I2C port #include <sys/ioctl.h> //Needed for I2C port #include <linux/i2c-dev.h> //Needed for I2C port #include <stdio.h> int main(void) { int file_i2c; int length; unsigned char buffer[60]; for (int i = 0; i < 60; i++) buffer[i] = 0; //----- OPEN THE I2C BUS ----- char *filename = "/dev/i2c-1"; if ((file_i2c = open(filename, O_RDWR)) < 0) { //ERROR HANDLING: you can check errno to see what went wrong printf("Failed to open the i2c bus"); return -1; } int addr = 0x77; //<<<<<The I2C address of the slave if (ioctl(file_i2c, I2C_SLAVE, addr) < 0) { printf("Failed to acquire bus access and/or talk to slave.\n"); //ERROR HANDLING; you can check errno to see what went wrong return -1; } //----- READ BYTES ----- length = 32; //<<< Number of bytes to read if (read(file_i2c, buffer, length) != length) //read() returns the number of bytes actually read, if it doesn't match then an error occurred (e.g. no response from the device) { //ERROR HANDLING: i2c transaction failed printf("Failed to read from the i2c bus.\n"); } else { printf("Data read: \n"); for (int i = 0; i < length; i++) printf("0x%02X, ", buffer[i]); printf("\n"); } //----- WRITE BYTES ----- /* buffer[0] = 0x01; buffer[1] = 0x02; length = 2; //<<< Number of bytes to write if (write(file_i2c, buffer, length) != length) //write() returns the number of bytes actually written, if it doesn't match then an error occurred (e.g. no response from the device) { // ERROR HANDLING: i2c transaction failed printf("Failed to write to the i2c bus.\n"); } */ return 0; } This code doesn't work: Data read: 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, 0x80, 0x00, I tried to cherry-pick from your reference code. I failed: The common_porting.h includes stm32f4xx_hal.h. Do I really need another micro controller to get results from the sensor? I can't imagine ... Thanks for your help Jörg ... View more