how to set manual gain mode in python?

Hi, I am a bit confused when using the qspectrumanalyzer which depends on two python deps:

soapypower, fft and device data
simplesoapy, a simple python-soapysdr encap

And this simple and beautiful PyQt works with my PlutoSDR through this long chain of invocations:

qspectrumanalyzer -> soapypower- > simplesoapy -> SoapyPlutoSdr -> SoapySDR

What's about this issue is this line of code, which determins if PlutoSDR is in AGC or manual: gain mode settings in SoapyPlutoSDR

`void SoapyPlutoSDR::setGainMode( const int direction, const size_t channel, const bool automatic ) {

gainMode = automatic;
if(direction==SOAPY_SDR_RX){
    std::lock_guard<pluto_spin_mutex> lock(rx_device_mutex);
    if (gainMode) {

        iio_channel_attr_write(iio_device_find_channel(dev, "voltage0", false), "gain_control_mode", "slow_attack");

    }else{

        iio_channel_attr_write(iio_device_find_channel(dev, "voltage0", false), "gain_control_mode", "manual");
    }

}

According to my tests in qspectrumanalyzer, setting gain values regarding to my consist sample signal, does NOT change the detected power of signal, which means, gain control does NOT work.

And,

I have a power controlled RF source to test power level of plotting, when i increase the power of the signal, the power in the plot does NOT change in the graph, however the noise floor drops!

Please correct me if my conclusion is incorrect, or misinterpreted.

I want to know how to set proper gain mode for Pluto by SoapySDR in python, please, so I can confirm if this is bug came from this quirky gain control method, which standard ways of gain mode/control didn't picked it up.

Thanks.

pothosware / SoapyPlutoSDR

how to set manual gain mode in python? #33