Address pca9956btwy

Transidico — Thu, 22 May 2025 15:18:18 GMT

Good morning,
I am using the pca9956btwy component with mcuxc242 to control a 7-segment display via i2c. Looking at the instruction manual I notice that if I configure with address 0x02 hexadecimal there is an R/W address with 04h next to it. Which address should I point to?

Transidico_0-1747926798716.png

I ask this because I set the component the first time with address 0x03 and everything works correctly, then I configured it with an address other than 0x03 and it doesn't respond.

So if I configure it with address 0x02 do I point to address 0x02 to write or 0x04?

Thank you in advice.

Best regards

Re: Address pca9956btwy

Harry_Zhang — Fri, 23 May 2025 07:08:18 GMT

Hi @Transidico

The table shows a 7-bit address in the "Binary (A[6:0])" column.

The final column "Address (R/W = 0)" shows the 8-bit address with the read/write (R/W) bit = 0 (i.e., a write operation). This is what is sent on the I²C bus.

If the hardware configuration gives you a 7-bit address of 0x02 (binary 0000010), then:

For a write, the 8-bit address on the bus is 0x04 (00000100).

For a read, the 8-bit address on the bus is 0x05 (00000101).

If your PCA9956B is configured with address 0x02 (AD2, AD1, AD0 = GND, GND, PD), then:

Use 0x02 in your code as the I²C address.

The I²C driver will automatically send 0x04 for writes and 0x05 for reads.

Harry

MCUXpresso IDEのトピックAddress pca9956btwy

Address pca9956btwy

Re: Address pca9956btwy