TMDSEVM572X: MIC device not working

Himani G

Part Number: TMDSEVM572X

Objective : To test microphone interface on EVM running on Android.

Action : Softphone Zoiper was installed on EVM running Android. Calling on EVM tested with call established between EVM
and an Android smartphone (also running Zoiper) .On EVM , microphone and Headset is connected at audio-in and audio-out interface.

Result : At Android smartphone side voice from EVM speaker is not received.

Further Experiment : To analyze the microphone interface of EVM, an APK (voice recorder from SPLEND)

was installed on EVM. It was tried to record the voice through microphone on EVM (a microphone is connected on audio-in).
When this recorded voice was played, no sound was obtained.

Please help in this regard

Thanks

over 7 years ago

0 Biser Gatchev-XID over 7 years ago

TI__Guru**** 393215 points

Hi,

If you look at the AM572x GP EVM schematic, you will see that the audio input is Line IN, it doesn't have mictophone bias: www.ti.com/.../TMDSEVM572X

0 Himani G over 7 years ago in reply to Biser Gatchev-XID

Intellectual 510 points

Hi Biser ,

Thanks for your response. Whats the kind of device which can be connected on the LINE IN on EVM ?

0 Krunal Bhargav34 over 7 years ago in reply to Himani G

TI__Mastermind 45065 points

Hi Himani,

The following threads contain useful information:

Regards,

Krunal

0 Himani G over 7 years ago in reply to Krunal Bhargav34

Intellectual 510 points

Hi Krunal,

Thanks for the links. These links and information from Baiser also confirms that mic CANNOT be used in the current state.

My doubt remains, :-

1. If I have to use a mic for live INPUT can something be used , some additional circuitry ?

2. What can be connected on LINE IN at the EVM.

Thanks again

0 Praneeth Bajjuri over 7 years ago in reply to Himani G

TI__Expert 6596 points

Himani,

Hope this thread helps

http://e2e.ti.com/support/processors/f/791/t/652068

Note: Sound Recorder App is not part of default android manifest from AOSP in Oreo (5.0+ Release)

0 Krunal Bhargav34 over 7 years ago in reply to Praneeth Bajjuri

TI__Mastermind 45065 points

Hi Himani,

In the thread pointed by Praneeth, an aux cable was used for testing purposes. One end of the aux cable was connected to a smartphone and the other end of the cable was connected to the audio-in jack.

Regards,
Krunal

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TMDSEVM572X: MIC device not working