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TMP112:

Noam Fishman1
Prodigy 20 points
Part Number: TMP112

Hi,

I am using Part TMP112 and trying to communicate with it through I2C channel, but receives no Acknoledge response back.

I measured all timing parameters and they seems fine.

after start I placed device address 0x90 (A0 is connected to GND), the next clock SDA should acknoledge with low logic but instead stays high.

attached are 2 pictures of the first byte. one with zoom in and one with zoom out. the unit in the pictures are in 100 usec.

and Zoom out:

what can be the reason of why there is no response??

thanks, 

Noam Fishman

  • 0
    TI__Mastermind 41955 points

    Hi Noam,

    The address should be 0x48 expressed as 7bit or 0x90 expressed as 8bit (with write bit.) Is your I2C host expecting the address to be supplied in 7 bit format? 

    In the first image, it looks like you could be generating a Start (at the cursor location) followed immediately by a Stop.

    In the second image, I only see 8 clock cycles, which are not 0x90. There should be 9 cycles total when ACK is included.

    thanks,

    ren

  • 0 in reply to Ren Schackmann
    Prodigy 20 points

    Hi Ren,

    Thanks for your advise. After start bit I added some delay before changing the SDA line and I got an acknoledge from the TMP112

    thanks a lot,

    Noam Fishman