write

Create a jetson object namedhwObj. Use the scanI2CBus function to scan the I2C buses on the Jetson board. In this example, the Jetson board has two I2C buses, i2c-1 and i2c-8. Each bus has a device at address 0x74.

hwObj = jetson;
addresses = scanI2CBus(hwObj);

Devices on i2c-1: 74.
Devices on i2c-8: 74.

Create an i2cdev object, i2cObj, connecting to the device on the i2c-1 bus.

i2cObj = i2cdev(hwObj,"i2c-1",0x74);

Connected to device at address 116 on bus i2c-1.

Write the value 42 to the I2C device. By default, the connection object writes the value as a uint8 data type.

write(i2cObj,42);

For the EEPROM, specify the address to write to as the first entry of data. Write the value 42 to address 3.

write(i2cObj,[3 42]);

To verify the data on the EEPROM, use the readRegister function to read the data from register 3. The read matches.

readRegister(i2cObj,3)

ans =

  uint8

   42

Create a variable named writeData that contains the hexadecimal data 0xA0B0C000.

writeData  = 0xA0B0C000;

In this example, the EEPROM uses the first byte of the data to write as the address to write to. Use 0x01 as the address.

writeData = writeData + 0x00000001; 
dec2hex(writeData)

ans =

    'A0B0C001'

Write the data to the I2C device. Specify that the data is the uint32 data type.

write(i2cObj,writeData,"uint32");

To verify the data, read the three bytes starting at address 1 and display them in hexadecimal format. The I2C object writes the data in little-endian format.

for i=1:3
    readOut = readRegister(i2cObj,i);
    dec2hex(readOut)
end

ans =

    'C0'

ans =

    'B0'

ans =

    'A0'