Reading data from I2C device in Embedded C - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to start an I2C transmission to the device address.

Embedded C

HAL_I2C_Master_Transmit(&hi2c1, [1], data, size, timeout);

Drag options to blanks, or click blank then click option'

A0xFF

B0x50

C0x00

D0xA0

Attempts:

3 left

💡 Hint

Common Mistakes

Using the 7-bit address without shifting.

Using the read address instead of write address.

The device address for writing is usually the 7-bit address shifted left by 1 with the write bit (0) added. 0xA0 is a common write address for I2C devices.

2fill in blank

medium

Complete the code to read data from the I2C device.

Embedded C

HAL_I2C_Master_Receive(&hi2c1, [1], buffer, length, timeout);

Drag options to blanks, or click blank then click option'

A0xA1

B0x50

C0xA0

D0x00

Attempts:

3 left

💡 Hint

Common Mistakes

Using the write address instead of the read address.

Not shifting the address before use.

The device address for reading is the 7-bit address shifted left by 1 with the read bit (1) added. 0xA1 is a common read address.

3fill in blank

hard

Fix the error in the code to correctly read a register from the I2C device.

Embedded C

uint8_t reg = 0x10;
HAL_I2C_Master_Transmit(&hi2c1, [1], &reg, 1, timeout);
HAL_I2C_Master_Receive(&hi2c1, 0xA1, &data, 1, timeout);

Drag options to blanks, or click blank then click option'

A0x10

B0xA1

C0xA0

D0x50

Attempts:

3 left

💡 Hint

Common Mistakes

Using the read address in the transmit function.

Mixing up device addresses.

The transmit address must be the write address (0xA0) to set the register before reading.

4fill in blank

hard

Fill both blanks to read multiple bytes from a register.

Embedded C

uint8_t reg = [1];
HAL_I2C_Master_Transmit(&hi2c2, [2], &reg, 1, 100);

Drag options to blanks, or click blank then click option'

A0x20

B0xB0

C0xB1

D0x30

Attempts:

3 left

💡 Hint

Common Mistakes

Using the read address in the transmit function.

Using wrong register address.

The register to read is 0x20. The device write address is 0xB0 for hi2c2.

5fill in blank

hard

Fill all three blanks to complete the I2C read sequence for a sensor register.

Embedded C

uint8_t reg = [1];
HAL_I2C_Master_Transmit(&hi2c3, [2], &reg, 1, 100);
HAL_I2C_Master_Receive(&hi2c3, [3], &value, 1, 100);

Drag options to blanks, or click blank then click option'

A0x15

B0xC0

C0xC1

D0x16

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up read and write addresses.

Using incorrect register address.

The register to read is 0x15. The write address is 0xC0 and the read address is 0xC1 for hi2c3.