AnsweredAssumed Answered

Sound Effect Delay - SGTL5000

Question asked by Daniel Martins on May 29, 2018
Latest reply on Oct 28, 2019 by Ernast Sevo

Hello Sirs,

We're developing an application using C++ for backend and QML for frontend. In this application we'll play some audios which format is WAV and length from 1 to 5 secs.

The problem is that when an audio will be played after no audio was played before under ~6 seconds, it is delayed about ~2 seconds before starting playing. So If the audio is played constantly, it has no delay.

For hardware we're using a Toradex SOM, with a iMX6DL and a codec SGTL5000. For software, we're using Linux, Yocto distribuiton and Qt for framework.

One important detail that we've tested. We put the oscilloscope on the pin module - pin15 - output for headphone left (output from SGTL5000). This pin Toradex recommend to use for audio system. At stand-by mode, this pin have the level 0 (0V). When I play one sound, this pin goes to level 1 (3.3V). After 5 seconds, this pin return to 0V. If you play a sound before this 5 seconds, the module maintain this pin in 3.3V - and the delay doesn't occur. But, the delay every occurs when this pin is 0V. So, I think maybe have one configuration about this (delay time to pin go to 0)

Are there any important configuration for this .. or for SGTL500??


Other important point, can you see the attach, with our screen. This is the log of our test. When we play any sound, and we cat dapm_widget value, we can see the paremeter 'PM State:' When we play any sound, this parameter goes to On - and any sound play with NO delay. After 5 seconds, this parameter goes to 'Standby', like in the picture. So, the next sound will be with the delay. We need to fid one way to configure this parameter to stay forever in ON


Are there any important configuration for this .. or for SGTL500??

We already tried to put a value (-1 and 1e6) to the field 'pmdown_time', but this doesn't work too.