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GPIO using sigmatcp

Kappus

September 06, 2019 22:53

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Hi

I'm using the DAC+DSP board + DAC add-on to create an active crossover for my stereo system.

I would like to use the signal detection block in sigmastudio to send a message back to the pi so it can power on external amplifiers. I've tried wiring the signal detect block to a register write block (writing to an unused register) and then reading that register -- it didn't work.

Reading the Sigmastudio documentation it seems like a gpio command is the normal way to operate. I see in sigmatcp.py that a function gpio_request and readwrite_gpio exist but without any documentation that I could find.

Can I get help on how I might implement gpio communication between a sigmastudio program the pi through sigmatcp?

Thanks.

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5 comments

• 0
  
  HiFiBerry team September 07, 2019 06:34

  Hi,

  unfortunately this is a misunderstanding. The GPIOs in SigmaStudio are GPIOs of teh DSP. They have nothing to do with the Raspberry Pi GPIOs. 

  However, we also had issues with the signal detector. IN the end, we built our own. Have a look at the latest DSP profile:
  https://github.com/hifiberry/hifiberry-dsp/blob/master/sample_files/dspproj/4way-iir-delay-mixer-asrccontrol.dspproj

  Best regards,
  Daniel

• 0
  
  Kappus September 08, 2019 22:43

  I see.

  Looking at that particular dsp profile, I do not see a signal detector. On some of the others such as 4way-iir-delay-mixer.dspproj , there does appear to be a custom signal detector in the mute block. Is that what you're referring to? At the right edge of that block you are using GPIO blocks (one to GPIO_7 and one to GPIO_13) -- how does that work?

• 0
  
  HiFiBerry team September 09, 2019 05:46

  GPIO7 is the LED on the board, GPIO13 is the MUTE function, both are connected directly to the DSP.

  Best regards,
  Daniel

• 0
  
  Kappus September 11, 2019 01:09

  Ah! That's useful. What are the other DSP GPIOs connected to?

  How would you recommend I approach my problem? I am running a python program on the PI and I need to recognize when the DSP is (and is not) getting a signal through the spdif input.

• 0
  
  HiFiBerry team September 11, 2019 07:26

  GPIO6 is also connected to the GPIO header on the Beocreate board, but NOT to the Raspberry Pi. Communication to the Raspberry Pi is only available via registers. Yu have to create a signal detector, write the result to a register and poll this using DSPToolkit.

  Best regards,
  Daniel