PicoMite: can we explain/fix "ticking" when using PLAY SOUND
Author
Message
thwill
Guru
Joined: 16/09/2019 Location: United KingdomPosts: 4090
Posted: 10:56am 17 Mar 2023
Can you point me at a picture of a "good" module, because either I'm rolling a 1 on my "recognise surface mount inductor" check, or none of them have one .
Given that the PicoGAME VGA 1.4 has the same click (though not "amplified" to the same extent) I don't think we can entirely blame PAM. Does the PicoGAME VGA have the power filter on the SD card that Peter mentioned above ?
I haven't had a chance to give the hardware another poke yet (i.e. try without the LCD/SD module attached) but I am still suspicious that this is specifically a PLAY SOUND issue, my lo-fi ears can't hear the same problem with PLAY WAV.
Peter, I've only executed it in my head but looking at the implementation of PLAY SOUND (Audio.c#1271-1296) it appears you always set sound_mode_{left|right}[channel] to nulltable first even if it was, for example, SineTable before and will be SineTable after the call. Is this code run in parallel with the actual playing ? in which case could their be a race-condition where you end up briefly "playing from the nulltable" and hence a click ? Or am I making s**t up; this is too close to the hardware for me to have any expertise.