STM CircleOS forum / Audio functions

sword · 2009-02-06 13:23:02

Hello everybody,

Has anyone get success to use the audio functions without the OS? If any does, can he share that with me. thank you.

regards

Francis · 2009-02-09 16:48:34

The audio functions are used for the 'welcome message' and the test procedure. You can see in the CircleOS source files how they are called. They would probably need to be improved..

sword · 2009-02-10 17:47:28

Hi Francis,

Thank you for your reply, in fact I have a problem with the recording functions. I want to change the frequency to 8KHz but I can realize that until now.
It seems like the codec isn't configured correctly , I am checking that.

I have one question about the JP2. I have taken the original primer2 project and I have tryed to watch the AUDIO_I2S2 pins status. The problem is that I have got only the SCK signal which indicates a frequency equal to 505Khz. The other pins doesn't showing any signals? Have you a suggestion about that?

Best regards
sword

Francis · 2009-02-10 18:02:14

I don't remember the exact detail, but the general lines are:
1. For recording you have to configure the chip in 'voice mode'
2. In voice mode, the clock must be permanent. It seems that there are not so many possible configuration. When we reach a working configuration, we kept it and I don't know whether different frequencies could be used with this combination codec/I2S.
3. To reconfigure the CODEC, we added recently some functions in CircleOS to write the CODEC registers (that are accessible via I2C). See AUDIO_WriteRegister.
I hope it helps... I will discuss with my colleague tomorrow and we will try to help you further..

sword · 2009-02-10 18:03:04

hi,

I have got them now
I have not understand very well the pin configuration on the schematic.
I will try now to investigate on the recording issue that I have described, I will let you know about the status.

Regards
Sword

Francis · 2009-02-10 18:20:10

For the pin configuration: we are connected to 2 different I2S ports (I2S2 and I2S3). The reason was that the internal I2S (of the STM32) works in one direction, and we wanted to keep the possibility of driving the codec in both directions (in voice mode).

klausr · 2009-02-23 21:50:54

Hello,

is a 44.1 kHz sample rate (playing) supported by circle os? I only found FRQ_16KHZ and FRQ_8KHZ declared in circle.h. If not, is this planned for future circle os versions?

Thanks, -Klaus

Francis · 2009-02-23 22:27:25

I believe that we have a large choice of sample rate to play something, but not for recording.

# 1 2009-02-06 13:23:02 Audio functions

Audio functions

# 2 2009-02-09 16:48:34 Audio functions

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# 3 2009-02-10 17:47:28 Audio functions

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# 4 2009-02-10 18:02:14 Audio functions

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# 5 2009-02-10 18:03:04 Audio functions

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# 6 2009-02-10 18:20:10 Audio functions

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# 7 2009-02-23 21:50:54 Audio functions

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# 8 2009-02-23 22:27:25 Audio functions

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