STM32 SPDIFRX Peripheral problem (interupts not firing)

Question

I am trying to make myself Digital audio to Analog audio converter

I have STM32F769i Discovery0: https://www.st.com/en/evaluation-tools/32f769idiscovery.html

Which has SPDIFRX and SPDIFTX ports

I found a fearly good starting point here: http://www.tjaekel.com/DiscoveryF7Audio/index.html Also the guy posted here: https://www.openstm32.org/forumthread921 But the guy used STM32746G Discovery: https://www.st.com/en/evaluation-tools/32f746gdiscovery.html Instead

So I went and tried to just get his SPDIF audio portion working on my board

My Project can be found here (I hope it compiles, with CubeIDE you never know what will happen :)): https://www.mediafire.com/file/n0s2z9p6nn735qg/SPDIF_Example.zip/file

I have no idea what I am doing wrong, but for some reason SPDIF_RX_IRQHandler (in stm32f7xx_it.c) is never called (LED never turns green, yea my debugging tehniques are primitive, but will explain why later)

So because of that HAL_SPDIFRX_ReceiveDataFlow_IT (in spdifrx.c) always returns HAL_TIMEOUNT, and of course no audio is ever played on the speakers

I am not sure what I am doing wrong When I start MCU I call BSP_SPDIF_Init() (defined in spdifrx.c) in main.c right after I take care of the clock

if (BSP_SPDIFRX_Init() != HAL_OK)
{
  Error_Handler();
}

And it appears it initializes all right, because I get HAL_OK back

Maybe I am not inializing GPIO properly from HAL_MspInit in stm32f7xx_hal_msp.c inproperly

I am realy out of ideas, what I am doing wrong, because the analog side of the audio does init, I can hear that as pop pop from the speakers when I power up my MCU, its just that SPDIF side has problems

I am is my setup crocked? I am using this component radio as my SPDIF transmitter (Hama DIT2000M): https://de.hama.com/webresources/article-documents/00054/man/00054821man_en.pdf

It says it has SPDIF Audio out (it says its digital over coaxial) I know its optical side is working fine because on my component receiver it plays just fine (it reports as 48khz Stereo)

Is my cable to long? I am using this cable: https://i.stack.imgur.com/3vp07.jpg

(not sure who made it)

Now why do I debug with blinking leds, because where my test subject is (my Hama receiver), there is no computer so…. Blinking leds it is, I would like to avoid aditional libraries and have a minimum working example, because you never know what problems they could bring so that's why LCD is not used right now

I hope someone has any advice, eather how to get any data in to SPDIF port (because right now for some reason, I don't get anything) or what I am doing wrong for my audio not to play, the usage of STM32F769i Discovery0 instead of STM32746G Discovery is probably not responsible 

I hope that this is a proper place for this king of questions, because I did ask a question regarding SPDIF on the STM forum: https://community.st.com/s/feed/0D53W00001z0RaqSAE

But didn't get any usefull advice there

Now SPDIF realy does not have much examples, there is only a polling example which does work (with the same cable), there is no interupt example, my interupt example (you can read the post on the STM forum post I linked) is not working as well (interupts are probably not broken right?)

So yea, I am lost a bit not sure what to do, and who to ask, so I tried here

PS: I know stackvoverflow does not like links to code, but I believe something is wrong with my project (interupts don't fire for some reason), and its realy hard to put this all into the question Thanks for Anwsering and Best Regards

Answer 1

I managed to solve this, I guess I did not initialize SPDIF GPIO properly

after setting this

GPIO_InitStructure.Pin = GPIO_PIN_7;
GPIO_InitStructure.Mode = GPIO_MODE_AF_PP;
GPIO_InitStructure.Pull = GPIO_NOPULL;
GPIO_InitStructure.Speed = GPIO_SPEED_FAST;
GPIO_InitStructure.Alternate = DISCOVERY_SPDIFRX_AF;
HAL_GPIO_Init(GPIOD, &GPIO_InitStructure);

to this

GPIO_InitStructure.Pin       = GPIO_PIN_12;
GPIO_InitStructure.Mode      = GPIO_MODE_AF_PP;
GPIO_InitStructure.Pull      = GPIO_NOPULL;
GPIO_InitStructure.Speed     = GPIO_SPEED_FAST;
GPIO_InitStructure.Alternate = GPIO_AF7_SPDIFRX;
HAL_GPIO_Init(GPIOG, &GPIO_InitStructure); 

interupts started to fire