Hi Don,
Flrig is not able to control a radio using Hamlib or control PTT using a GPIO pin on the Raspberry Pi.
However, Fldigi has both those capabilities. If your question is really about Fldigi, to control the RigPi CW PTT line, go to Configure>Rig Control>GPIO and put checks in BCM 17 and Value. Fldigi will now control the RigPi PTT line (as you can see by the RigPi PTT light).
In Fldigi you can also use the Hamlib interface for rig control and select CAT PTT. Hamlib CAT PTT will control the RigPi CW PTT line if you have your radio being controlled by RigPi and have Fldigi Hamlib set to Hamlib NET rigctl (Stable).
In an earlier message you said you wanted to hear receive audio when using digital modes. When RigPi is using the audio chain for digital modes, it can't share that chain for rx audio. You have to turn off Mumble to avoid a conflict.
--Howard
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