Connecting 8ohm speaker to stm32H743 EVAL Board.

[Murali_chikkanna]

Hi ST,

I am using a stm32h743I EVAL Board and trying to connect the 8ohm speaker on CN19. I am using SAI_AudioPlay example from the STM32Cube_FW_H7_V1.11.0 package. I have followed the readme file and got the headphones working fine; to make the speaker working, I have changed the lines below in the main file.

codec_init.InputDevice = WM8994_IN_NONE.

codec_init.OutputDevice = AUDIO_OUT_DEVICE_SPEAKER.

codec_init.Volume = VOLUME_IN_CONVERT (60).

But can't heard any sound out of my speaker and after analyzing the init function inside the wm8994.c file, I have done some modifications and the I can be able to hear the sound through speaker, but the sound is very low.

Can anyone suggest me, is there any possibility to increase the volume on the speaker, I have gone through almost all the registers and tried increasing the sound of the speaker but failed. Any help really appreciated.

Thanks,

Murali Chikkanna  

[Andrew Neil]

CN19 connects direct to the WM8994ECS/R audio CODEC:

Have you checked the CODEC datasheet to see if that output is suitable for an 8-ohm speaker?

[QSHAO.1]

The WM8994's speaker output is configured as Mono mode by SPKMODE pin connected to GND. so you may refer to Speaker driver performance mentioned in the WM8994 datasheet to justify if it's enough to power your speaker.

[PGump.1]

Hi,

R149 & R156 being 180R is NOT good news for an 8ohm speaker, regardless of what the data says...

I hope that helps.

Kind regards
Pedro