开云体育

Hi,

Just a quick question, because it's hard for me to test at the moment.

Does the sound card emulated by the QDX's STM32 support full duplex mode?
Is it possible to simultaneously output a tone to it and read samples from
it?

If yes, what will be read from the sound card in TX mode, when the QDX is
transmitting? Silence?

Of course it doesn't make much sense, because samples written would be
ignored in RX mode, and there won't be anything meaningful to read from
the QDX in TX mode, but it starts to make sense if we want to switch
between RX and TX with the hardware serial port, at the same time using
the PC to set the exact TX frequency (by continuously sending the tone to
the QDX to be used when switched to TX and ignored in RX) and monitor the
band.

A side question. QDX switches to TX after we send the proper CAT command
("TX;") to the serial port. This switching, as everything else in this
universe, takes some time. Is this time predictable and can we expect it
to be reasonably constant (to start the envelope not too early and not too
late, without monitoring the TX signal from the MCU)? Or maybe we should
add an additional delay before starting the envelope to wait for the
synthesizer to stabilize?

Yes, I'm still exploring the possibilities to design the CW mod (and it
would be even better if QDX turned out to switch quickly enough to support
QSK) :)