PCA9534: PCA9534

Will1979

Part Number: PCA9534

Hi:

I am debugging PCA9534. However I am having the I2C communication problem with this part. Here is the schematic I designed for my application for your reference.

I tried to communicate with the PCA9534, but I did not get ACK from the device. and I am sure I've sent the command successfully. In the schematic design, I set the I2C address to 0100100. Please see the waveform I measured on the SCL and SDA. You would see I accessed the device with address 7h'24, but did not get ACK from the PCA9534.

I need your help on this issue and see what could be the problem. Thanks.

over 5 years ago

0 BOBBY over 5 years ago

TI__Guru 58860 points

Hey Will1979,

Do you mind trying to talk to the device with a write transaction instead of a read transaction? If the device ACKs to the write transaction it means that it NACK'd your read because you have not addressed the internal pointer in the device so it does not know what register you want to read from. Figure 26 in the datasheet provides the correct way to perform a read transaction and get an ACK.

-Bobby

0 Will1979 over 5 years ago in reply to BOBBY

Prodigy 20 points

Hi Bobby:

Thanks for your quick response. I will try it.

Will

0 BOBBY over 5 years ago in reply to Will1979

TI__Guru 58860 points

Hey Will,

Just checking in, were you able to resolve the issue by trying a write transaction?

-Bobby

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PCA9534: PCA9534