How to get work SPKR_OUT on STM32F469I-DISCO

[Tomas Zahradnik]

Posted on September 18, 2017 at 08:00

Hi all,

I'm trying to get work speaker output on my Discovery kit (STM32F469I-DISCO) but not succeed yet. I have connected

https://www.gme.cz/reproduktor-ls45n-3-r8-45mm-8ohm-1w

on pins 15 and 16 of extension connector CN12 and have used example 'Audio_playback_and_record' from 'STM32Cube_FW_F4_V1.16.0' repository, but cannot hear anything.

I have changed configuration AUDIO_PLAYER_Init in waveplayer.c from OUTPUT_DEVICE_AUTO to OUTPUT_DEVICE_BOTH and OUTPUT_DEVICE_SPEAKER but still not working.

Headphones on 3.5 jack output works fine and when I connect speaker to the headphone's output, I can head sound, so speaker is OK.

I have looked briefly into source code in BSP and couldn't find any handling of PE3 which should be used for switching between Headphones and speaker output which looks strange. I have tried to find any existing solution or similar issue and found just

https://community.st.com/0D50X00009XkZevSAF

where WM8994 chip is used. But on STM32F469I kit is used CS43L22 chip.

Do you have some suggestions for me?

Thanks for your help.

Tomas

#speaker #stm32f469i-disco #audio-playback #cs43l22

[Imen.D]

Posted on September 19, 2017 at 15:47

Hello,

Did you followed the different steps in the readme.txt for hardware configuration ?

Did you tested that speaker is working on another connector?

Kind Regards

Imen

[Tomas Zahradnik]

Posted on September 19, 2017 at 21:38

Hello Imen,

I have read readme.txt from example folder and there is just mentioned JP4. But his jumper is not on STM32F469I-Disco. I read also Datasheet for Discovery kit and in chapter 6.5. Analog output is some mention about PE3. I suppose that this signal should be somehow handled in BSP analog driver.

I have also tested speaker on headphone output as I wrote and I could head some sound. So the speaker is fine (it's also brand new).

Documentation at the beginning of stm32469i_discovery_audio.c describe to call BSP_AUDIO_OUT_Init with argument OUTPUT_DEVICE_HEADPHONE1 or OUTPUT_DEVICE_HEADPHONE2 but later is described as OUTPUT_DEVICE_SPEAKER or OUTPUT_DEVICE_HEADPHONE. But I suppose that this is just not updated comment.

What I also don't understand is PE3 signal. Should I control it independently to BSP_Audio driver and should I Set it or Reset it for enabling speakers?

So any other idea? Does anybody tested this functionality?

Best regards

Tomas

[Imen.D]

Posted on October 17, 2017 at 16:35

Hello,

To get sound on the speaker, you should connect his loudspeaker (Left, Right and GND) to SPKR_OUTAN (pin 15 on CN12), SPKR_OUTAP(pin16 on CN12) and GND pin.

SPKR/HP mapped on PE3 is an input Speaker/Headphone switch. It powers down the left and/or right channel of the speaker and/or headphone outputs as described in CS43L22 codec datasheet.

To power down the channel of the speaker/headphone, you have to configure this pin as input and connect it either to GND or VDD.

However, this pin is not exposed on the STM32F469I-Discovery, then it cannot be controlled. It?s a choice made to not power down speaker/headphone; so no BSP API is supporting this switch.

After checking, the ?Audio_playback_and_record? application worked fine with the sound on headphone and speaker (on SPKR_OUTAN and SPKR_OUTAP pins).

Kind Regards,

Imen.