LimeSDR Mini FullDuplex Test Fail


I am trying to do a simple test of the LimeSDR Mini’s ability to transmit and receive at the same time. I emit a sinusoidal wave and check whether I receive it correctly.

Here’s my implementation in GNU Radio Companion:

Really simple; the slider is to control the frequency freq1 at which the signal source operates and the TX transmits. freq is the frequency at which RX receives.

But it doesn’t work (I only receive noise). Is there a trivial mistake in the flowgraph?

EDIT: Identified the problem: I was looking at a tiny freq window with fft sink but set the freq1 to values outside that window.

You ‘Signal Source’ block is generating a signal at 2500 MHz, try putting 1 MHz instead (then actual signal frequency is 2501 MHZ, because Lime is up-converting to 2500 MHz).

You also might want to leave out the throttle block when using real hardware. Try to use a resample block if you would like a slower sample rate at your Gui Sink