Issue with I2C Communication Between MK22FN512VLL12 and ADS7924 ADC regarding slave acknowledgement

[guruprasad13]

Dear NXP Support Team,

I am currently working with the MK22FN512VLL12 microcontroller and attempting to establish I2C communication with the ADS7924 ADC. I have set the slave address to 0x49 to initiate communication; however, I am experiencing difficulties. Additionally, I have tried the slave address 0x92 without success.

The primary issue I am encountering is the lack of acknowledgement (ACK) from the ADS7924 when I attempt to communicate. Interestingly, when I use random slave addresses, I receive responses, indicating that the communication setup may not be entirely faulty.

I have attached a document detailing my configuration and steps taken thus far for your reference.

I would greatly appreciate your guidance on resolving this issue. Thank you for your assistance, and I look forward to your prompt reply.

Best regards,

Guruprasad

[Pablo_Ramos]

Hi @guruprasad13,

Analyzing your configuration I didn't see anything off. However, you could try to test the integrity of your I2C module with an example.

Also, we don't have the required hardware in order to make the pertinent test, could you send us a screenshot of the I2C communication using a logic analyzer or an oscilloscope?

Please let me know your results.

[guruprasad13]

Hi @Pablo_Ramos,
I have attached the clock waveform for your refernece.
In this waveform, for 9th clock pulse, slave is not driving the SDA line low for acknowledgemnt from slave device as it remains high. And also in data line waveform i am getting little disturbance at end after sending a bit. I am sending slave address as 0x92.

[Pablo_Ramos]

Hi @guruprasad13,

An apology for the delay response.

Comparing the frame with the once shown in the ADS7924 datasheet it appears to be that is not a configuration issue, this because both frames are identical except for the ack/nack bit.

You could test the I2C module of your chip with a board-to-board communication with one of our examples (i2c_polling_b2b_transfer_master/slave). Also, you can use the configurations shown in these examples in order to communicate with ADS7924, by changing the address.

Could you check the connection of the ADS7924? Also, you can try changing the A0 to GND in order to change the address.

Please let me know your results.