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Using the INA219EVM

Bharathi R
Prodigy 50 points
Other Parts Discussed in Thread: INA219, INA219EVM

Hi,

Have recently purchased the INA 219 EVM board.  It comes with the USB board and the test board. Th test board  has the INA 219 chip on it.  I have  another board where I have the INA219 chip ( close to 15) mounted. It has the sense resistor and the I2C address set. Question is how to talk to these INA chips  on my board using the software and the  EVM board.

Please note: Have removed the test board and connected the SDA ,SCL and gnd pins to the connector present in the USB board. This is not working. Using the software, do changes and when I read these changes, they are all gone. Also, when I try to read  continuously for values, the software shows the device is shutdown.

Looking forward   to your help

Bharath

  • 0
    TI__Genius 14825 points

    Bharath,

    This seems like a workable idea. I'll set up my EVM here and figure out what you need to make it go with a fly-wire interface.

    Best regards,

    Jason Bridgmon

  • 0
    TI__Genius 14825 points

    Bharath,


    I looked through the hardware description of the INA219EVM user guide, and I re-read your question; do you have a power supply hooked up?  You only mention SCL, SDA, and GND.  The device will need a supply, and it will need to power the part and also be attached to the pull-up resistors on SCL and SDA.

    Next, do you have the GND of your board tied to the GND of the controller board?

    Third, is the I2C address set correctly in hardware to match the software?

    Let me know if this debugging doesn't get the software working.

    Thank you,

    Jason Bridgmon

  • 0 in reply to Jason Bridgmon
    Prodigy 50 points

    Jason,

    Yes, have the  J5 supply  connected and  my board and evm board  ground connected to my board gnd.(SDA and SCL also connected). These are the 3 connections to my board. On my board we have the all the setup done (shunt resistors present, I2C address set-up). I write to the registers and when I read don not  see the updated values. It read the  default values. When I hook the test board, it works. 

    Note: I have 15  INA devices on my board

  • 0 in reply to Bharathi R
    TI__Genius 14825 points

    Bharathi,


    I assume your 15 devices all have different I2C addresses (As specified on page 10 of the data sheet)?  And I assume you are just choosing one device, writing to it, and then reading back from it?


    Do you have one pullup for the whole SCL and whole SDA line or several parallel pullups?  What size?  If you're getting data back that is the default data, it may be fine driving from the device but maybe not from the controller board...I don't know since I haven't tried driving 15 devices from it.  It's probably not an issue but I'm trying to figure it out.

    Could you share the schematic with me?  You can post it here or send it to Bridgmon_Jason@ti.com if you want to keep it from the public eye.

    Also, please hook up an oscilloscope and take some waveform screenshots of the SDA and SCL lines for the write and read operations, and if you could do it with the good EVM board and the bad 15 device board for comparison, that would be most excellent for debugging.

    Thank you,

    Jason Bridgmon