Hello Rob,
?
Thanks for your advice.
According my configuration I keep the debouncing and pullup circuit since the GPIO is keyed by the relay from my homemade K3NG keyer . It will protect the GPIO since this part is really sensitive. In addition it provide a little filtering regarding any RF issue which is always possible in our hobby.
The possible issues are maybe ?the following assumptions :
-I am using a raspberry PI 3B+ which is behind the RPI 4 in terms of CPU and performance. Currently the CPU load is about 40 to 50 % when using Quisk which is acceptable but not as perfect . My assumption this load is participating to the latency I have noticed.
-I am using the Behringer Ucontrol / UCA202 Interface audio USB for the IN/OUT IQ signals. This device is supposed to be low latency therefore I cannot find any specification regarding the latency provided . To drive this USB audio device I am also using ALSA.
For Quisk in the Config menu my current latency adjustment for the buffering is 150ms , I need to adjust to 50ms in order to reduce the latency when I am? keying the paddle. Therefore at 50ms the audio is downgraded and I notice some clipping (Buffering).
Obviously I did not perform an accurate measurement but even visually when I am keying the paddle and look carefully to the RS-HFIQ I can cleary notice the lag. I will say it is about 100 up to 2 or 300ms . For voice no issue but? very difficult to adjust the keying of the paddle when using CW mode .
As you said , the solution will be to provide a monitoring audio with the GPIO at the ouput of the Raspberry .
The other alternative I choose currently is to use an external Keyer and use the BUG mode in order to key the raspberry using only the dash. Since I still have my homemade K3NG CW keyer this alternative is in fact not so bad and working perfectly. The K3NG is full of capabilities and features and since we are using Quisk or any other software to drive our SDR TRX , using K3NG is something interesting since this keyer is capable to be driven by software in particular with logging software (I am using CQRLOG and Winkey capabilities).
73s Didier / F5NPV
Didier F5NPV