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A couple of questions about RX Gain Control

Question asked by S.Garza on Jul 11, 2016
Latest reply on Aug 12, 2016 by S.Garza

In our application we are setting the Gain Control Mode for RX1 and RX2 to "Manual", and setting  the Hardware Gain values to the numbers we need.

However since in our application we are doing a Frequencies' sweep from an Initial to a Final Frequency with a variable number of  steps in between, in a process of Setting a Frequency, waiting 50mSec (for the next time the function to fill the buffer with data is called), Retrieve the data from the buffer and Store it together with the Hardware Gain and RSSI values we have for RX1 and RX2 for the frequency set at that moment, we noticed that the Hardware Gain values are getting changed from our initial settings.

Then looking at  "RX Gain Control" wiki.analog.com, we see that in MGC mode, the BBP controls the gain index pointer(s) of a gaintable. Therefore, since we need to always have full control of the Hardware Gain values, we would like to know:

What could be the best way to achive this?

If it is by making our own gaintable(s), where can we find the one being used now by the Demo Software?

    we did not find any instance of gaintable or gain_table_config in the source code, nor in the

    folders: /sys/bus/iio/devices/iio:device1, or /sys/bus/iio/devices/iio:device1/lib/firmware  mentioned in "Loading

    a gain table" / "Reading a gain table" of  "RX Gain Control" in wiki.analog.com

Or, is there a way to disable the control of BBP and keep the Hardware Gain Settings with the values we desire?

 

Many Thanks in advance for your support,

 

 

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