Unable to read registers from ISM330IS
Hello,
I am trying to get a ISM330IS IMU working. I have ordered a development kit from Mouser / ST Micro with the following board number https://www.mouser.in/ProductDetail/STMicroelectronics/STEVAL-MKI230KA?qs=amGC7iS6iy%252B%252BWAEBNHSnWw%3D%3D (photos are also attached).
I have done the wiring referring to the User Manual Section 5.1. (photo is also attached). I am using a I2C to USB converter (photo is attached below) to read the data in a linux based Ubuntu 22.04 PC via library i2c-dev.
Link to User Manual I am following: https://www.st.com/resource/en/datasheet/ism330is.pdf
I am able to connect to the I2C bus and connect to Slave Address as per User Manual Section 5.1.1.1.
I am facing a problem:
- When I am trying to read the IMU data through any register (for Temperature sensor or WHO_AM_I from user manual page 30), all the values are coming out to be zero constantly. I am unsure what the reason for this is. (I am not getting any kind of runtime errors).
Does someone have an idea why this could happen? Perhaps I am missing something to start the communication via I2C. Or something needs to be triggered before I start reading these registers on the sensor hub?
Here’s the code I am using:
void connect_i2c(std::shared_ptr<rclcpp::Node> imu_node){
const char* i2cDevice = "/dev/i2c-1"; // I2C bus number
i2cFile = open(i2cDevice, O_RDWR);
// Open the I2C device file for reading
if (i2cFile < 0) {
perror("Failed to open the I2C device.");
}
else{
std::cout << "I2C open successful" << "\n";
}
const uint8_t i2cAddress = 0b1101010; // I2C device's address
if (ioctl(i2cFile, I2C_SLAVE, i2cAddress) < 0) {
perror("Failed to set I2C address.");
}
else{
std::cout << "Slave open successful" << "\n";
}
// Write a command or data to initiate communication
//(replace 0x01 with your specific command)
unsigned char command = 0x00;
if (write(i2cFile, &command, 1) != 1) {
std::cerr << "Failed to write data to the ISM330IS sensor" << std::endl;
}
// This will run iteratively
run_i2c(imu_node);
}
void run_i2c(std::shared_ptr<rclcpp::Node> imu_node){
sleep(2);
rclcpp::Rate loop_rate(5);
while (rclcpp::ok())
{
int registerToRead = 0x0F; // Replace with the register address you want to read
if (write(i2cFile, ®isterToRead, 1) != 1) {
perror("Error writing register address");
//return 1;
}
uint8_t data;
if (read(i2cFile, &data, 1) != 1) {
perror("Error reading data");
//std::cerr << "Error reading data" << std::endl;
//return 1;
}
std::cout << "Data from register 0x" << std::hex << registerToRead << ": 0x" << static_cast<int>(data) << std::endl;
loop_rate.sleep();
rclcpp::spin_some(imu_node);
}