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Full scale voltage read when reading continuously from LTC2945 power monitor

Hi,

We are using LTC2945 to monitor voltage ,current and power from a few sources.

We need to continuously monitor the current ,voltage and power from four sources.

We are using the in-built ltc2945 which come with the kernel. We use kernel version 4.8.17.

When trying to read voltage , current and power in continuous mode we are getting full scale voltage of 102.4V instead of the actual values.

The problem does not happen if I provide delay between reading the current , voltage and power values from each of the LTC2945 sensors.

My questions are as follows

1) Is there any time delay we need to provide between reads of voltage, current and power values when working with continuous mode  . If yes what is the recommended time  delay?

2) How do we confirm when the ADC conversions are over when working in continuous mode.?

4) What are the steps to put the LTC2945 in single shot mode ?

Warm Regards,

Sonu

  • Hi Sonu, 

    I moved your query to the proper community, people here will be able to help you.

    Cheers,

    Ivan

  • Greetings Sonu,

       Regarding your LTC2945 questions:

    1) Is there any time delay we need to provide between reads of voltage, current and power values when working with continuous mode. If yes what is the recommended time delay?
       The LTC2945 has a typical ADC conversion rate of 7.5Hz, but can be as low as 6Hz. 
    2) How do we confirm when the ADC conversions are over when working in continuous mode.?
       In continuous mode there is no register bit indicating when the ADC is busy.  The only indication that a conversion is complete will be through the updating of the register values for that reading.

    4) What are the steps to put the LTC2945 in single shot mode ?
     To make a snapshot measurement, set CONTROL register bit A7 and write the two-bit code of the desired ADC channel to A6 and A5 (Table 3 in thee datasheet) using a Write Byte command. When the Write Byte command is completed, the ADC converts the selected voltage and the Busy Bit (A3 in the CONTROL register) will be set to indicate that the conversion is in progress. After completing the conversion, the ADC will halt and the Busy Bit will reset to indicate that the data is ready. To make another snapshot measurement, rewrite the CONTROL register.
    I hope this helps!
    Thank you and best regards,
    Brad