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INA219: Duel I2C address reported

Part Number: INA219

Hi,

I have a INA219 connected to a Nucleo-F401RE. The address pins of the INA219 are both connected to GND. This should result in a I2C address of 0x40 if I am not mistaken. When I run a I2C scan on my Nucleo-F401RE (after setting it to 7-bit address mode), there are two adresses being reported, 0x00 and 0x40. How can two addresses be reported for the INA219 when there is only one device connected?

My code uses the 0x40 address to communicate with the INA219 over I2C. This operation works fine and I am able to read and write to the registers. 

Thank you for your time and response. 

  • Hello,

    You are correct in the fact that the INA219 will have an address of 0x40 if A0 and A1 are grounded. We should make sure that there is nothing else on the I2C bus. 

    If you try to read data from the 0x00 address do you get anything back? I want to make sure that if you try reading from the 0x00 address it will not give you the same data as the 0x40 address. 

    One other thought is that you maybe seeing the salve address of the Nucleo-F401RE as the 0x00 address. These devices may have a programable salve address which could be set to 0x00.

    If you have any questions please reply

    Regards,

    Castrense

  • Deveraj,

    It's been a while since we heard from you, so I'm hoping you got the assistance you needed here! I am marking this as resolved. Please, if you need additional support, feel free to post here or begin a new forum topic.