STM32F7 discovery audio line-in

[konrad2399]

Posted on October 06, 2015 at 21:10

Hi.

I've started to play with STM32F7 discovery. I got to DSP audio example from hands-on and I would like to use line-in instead of microphones. Unfortunately when I've changed

BSP_AUDIO_IN_OUT_Init(INPUT_DEVICE_DIGITAL_MICROPHONE_2, OUTPUT_DEVICE_HEADPHONE, 90, DEFAULT_AUDIO_IN_FREQ);

to

BSP_AUDIO_IN_OUT_Init(INPUT_DEVICE_INPUT_LINE_1, OUTPUT_DEVICE_HEADPHONE, 90, DEFAULT_AUDIO_IN_FREQ);

Only thing that's coming is noise. Could anyone help me to get line-in working? Best regards Konrad #https://github.com/laurent-lator #stm32f7-audio

[konrad2399]

Posted on January 30, 2016 at 15:48

I can't believe it's that simple 🙂

Thank you.

[hpeev1972]

Posted on January 30, 2016 at 21:15

You can try this hex file.

________________ Attachments : Line_in_2_phones.hex : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006Hzid&d=%2Fa%2F0X0000000bOh%2F8i4ra6h9VbGhL8kkfHfdUEAr04UF5HBm5_IqxV5FNn4&asPdf=false

[Torsten Jaekel]

Posted on February 18, 2016 at 23:25

Yes, volume < 70!

I made same experience. And, if I remember correctly: the ADC/DAC chip is configured with an audio cross connect (inside the onboard ADC/DAC chip, this WM9... chip). I have modified slightly the config for this chip (done via very low level driver code, via I2C) and it works fine for me. I think, this DAC chip has feedback or taken some audio from another channel/input and volume > 70 results in just distortions (noise) due to active audio cross/feedback.

[misterstarshine]

Posted on October 07, 2016 at 17:50

Hi David.

I managed to build your program with System Workbench. Have you found out what causes the noise yet? The noise level is just totally ridiciolus. Totally useless in its current configuration.

[Chirag Parmar]

Hello Nickname8353,

Can you tell me from where can I finde DSP example code for STM32F7 Discovery? I am trying to generate audio signal from audio out. and also taking input from audio line in and same signal to audio out. It will be great helpfull.

Thank You.