Using LimeSDR-Mini for TDOA

chibill · 21 May 2021 01:16

I am looking into doing Time Difference of Arrival with my LimeSDR Mini using the two dipole switching method of making artificial doppler.

I am trying to figure out how to make the LimeSDR generate my switching signal from the FPGA so I know exactly in my I/Q samples which antenna was in use at the time.

andrewback · 22 May 2021 10:08

There is a Lime Suite FPGA GPIO example:

github.com

myriadrf/LimeSuite/blob/master/src/examples/gpio_example.cpp

/**
    @file   gpio_example.cpp
    @author Lime Microsystems (www.limemicro.com)
    @brief  GPIO example
 */
#include <lime/LimeSuite.h>
#include <iostream>
#include <chrono>
#include <thread>

//Device structure, should be initialize to NULL
lms_device_t* device = NULL;

int error()
{
    if (device != NULL)
        LMS_Close(device);
    exit(-1);
}

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But I’m guessing you actually mean driven direct via the FPGA and in which case I suspect this will mean modifying the gateware. E.g. so that every N samples a GPIO is automatically toggled.