+ // optionally call set_output_card(...) on the adapter
+ app.add_stream_adapter(Codec2RxAdapter::new()).unwrap();
+```
+
+This is how you set up to transmit Codec2 audio:
+
+```rust,ignore
+ // optionally call set_input_card(...) on the adapter
+ let mut tx = Codec2TxAdapter::new(args.callsign.clone(), reflector);
+ let ptt = tx.ptt();
+ app.add_stream_adapter(tx).unwrap();
+```
+
+Later, after you have called `start()`:
+
+```rust,ignore
+ ptt.set_ptt(true);