SDA is pulled low on 9th clock pulse!(NTAG Tag NT3H1101 )

[tarikon]

Hello Dears,

I am working on interfacing MSP430 with NT3H1101 with I2C. I could not read from the NTAG as the SDA is pulled low on 9th clock pulse. I found that it is related to clock stretching bit on register I2C_CLOCK_STR. as Kan_Li i may access the E9h via RF interface, i could access to configuratio register throught the NFC I2C demo, I still receive a Nack from the chip?

what shpuld i do that i can communicate with the NTAG?

best regards,

tarik

[Kan_Li]

Hi Tarik,

Do you mean the I2C access still failed due to the SDA pulled down issue? Please kindly clarify.

Have a great day,
Kan

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[tarikon]

Hi Kan,

There was no other NT3H1101 on the 2C bus, I believe the I2C configuration of MSP430 are correct, but if you are interested in checking my code, I can share it here

best regards,

tarik

[Kan_Li]

Hi Tarik,

How many boards did you test? Did they behave the same? From your snapshot, the baud rate was not very high, right? Have you ever tried with a lower speed? Please kindly clarify.

Thanks for your patience!

Have a great day,
Kan

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[tarikon]

Hello Kan,

I have tested only on one board(the PCB board where i have soldered the NTAG), the baud rate was of 100Kh only, II ve tried once with 80Khz but still the same probleme

the thing I want to tell is that, I have tried it once and it worked somehow but I have an ACK from the TAG with a delay of 70ms(between the 8 clock and 9 clock) but after running it again it still send a NACK

best regards,

tarik

[tarikon]

Hello Kan,

I meant the I2C access still failed due to the SCL pulled down 9th clock.

kind regards.

tarik

[Kan_Li]

Hi Tarik,

Was there only one NT3H1101 on the I2C bus? Please check if the I2C configuration of  MSP430 was correct.

Have a great day,
Kan

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