Suspended on enable clock for InputMux.

[CzyzyK]

Hello.

I use LPC55s36 with unmodified i2s_dma_transfer example. From default pins i shorted JP3 1-2, JP53 1-2 and JP50 1-2, like the example says to do. Terminal says that it went throught all of the code and, theres no errors in terminal. Terminal:

Configure codec

Configure I2S

Setup looping playback of sine wave

But i can't hear anything in headphones. What could be the issue?

clock not working for input mux.PNG

[Harry_Zhang]

Hi @CzyzyK 

You can observe the output effect through an oscilloscope.

According to the schematic, you can measure these three signals.

HangZhang_0-1728629515364.pngHangZhang_1-1728629530179.pngHangZhang_2-1728629547183.png

The above is the result of my test, you can refer to it.

BR

Hang

[CzyzyK]

@Harry_Zhang I checked it, there is no signal coming to jack.
I also tried flashing instead of debugging and still nothing.

[Harry_Zhang]

Hi @CzyzyK 

I checked the lpc55s36_i2s_dma_transfer demo readme.

Board settings
==============
Short JP50 1-2,JP53 1-2

HangZhang_0-1728875609242.png

But in your setting,

"From default pins i shorted JP3 1-2, JP53 1-2 and JP50 1-2, like the example says to do. "

Why shorted JP3 1-2?

HangZhang_1-1728875809113.png

BR

Hang

[CzyzyK]

Hi @Harry_Zhang  , the description says to do so in import SKD examples. Removing shorting on JP3 1-2 didn't change anything.

i2s dma example description.PNG

 

[Harry_Zhang]

Hi @CzyzyK 

Thanks for your picture.

May I ask if you can measure the waveform?

BR

Hang

[CzyzyK]

Hi @Harry_Zhang , how i can measure those signals, i didn't find anything in manual.

[Harry_Zhang]

Hi @CzyzyK 

1. For CDC_I2S1_RX_BCLK_OnBoard signal, you can measure  the J9 Pin16.

HangZhang_0-1729493910358.png

2. For CDC_FC7_I2S_TX_OnBoard signal, you can measure  the J22 Pin2.

HangZhang_1-1729494056345.png

3. For CDC_I2S_WS_OnBoard signal, you can measure  the J22 Pin4.

HangZhang_2-1729494173844.png

BR

Hang

[CzyzyK]

Hi @Harry_Zhang , I2S and RX is fine i think, but TX is diffrent.

I2S:

i2s.jpg

RX:

rx.jpg

 TX:

tx.jpg

[Harry_Zhang]

Hi @CzyzyK 

RX_BCLK and TX are fine.

Regarding the WS signal, may I ask if you are testing J22 Pin4?

BR

Hang

[CzyzyK]

Hi, @Harry_Zhang I checked this ones TXD on pin 4, with is near RX pin.

is2 rx tx.PNG

[Harry_Zhang]

Hi @CzyzyK 

The pin measured is correct.

BR

Hang

[CzyzyK]

Hi @Harry_Zhang
So what could be wrong?

[Harry_Zhang]

Hi @CzyzyK 

HangZhang_0-1730368582349.png

HangZhang_1-1730368975726.png

BH19 should be connected to BH20, but the board defaults to BH20 and BH21. You can try testing point BH20 to see the waveform.

BR

Hang