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SigmaDSP level meter readout via I2C

Question asked by ElmarJ on Jun 1, 2016
Latest reply on Oct 30, 2016 by chefmech

Hi,

 

I am trying to readout some level detectors from my ADAU1702 via the host processor, but I cannot find enough documentation to help me further. I found two interesting topics:

DSP read back for data capture

Monitoring average and instantaneous signal levels

 

What I want to achieve:

- Host MCU reads out current and average RMS value of a level meter.

- Host MCU further processes it to a level in dB.

 

First problem is the most important now.

  1. I made a schematic with a Single Band Level Detector in it, connected to an audio stream.
  2. Link/compile/download / download to EEPROM
  3. Turn on level meter once connected with USBi; log data with Logic Analyzer
  4. Analyze data stream and try to copy

 

Step 3 is getting interesting, this is what my I2C bus does while reading out the level meters:

 

W68, 08, 1A, 04, 4E

W68, 08, 1A, R68, 00, 00, 14

 

First line:Write to 0x68 (I2C slave address), register 0x081A: Data capture reg, data= 0x044E

Second line:Readout data from reg 0x081A, 0x000014

 

I expect that the last value (0x000014) is one of the volumes, but I can not really correlate it.

 

Can somebody tell me at which PC to read out the actual volume and the envelope, and how to correlate this with the .params file?

 

Can somebody tell me how to the read value to dB's?

 

 

 

 

 

Below:

Data from my compiledDSP image, the .params file.

Cell Name     = Level2
Parameter Name= SingleBandLevelDetwOutDisplay2ndGen5TCONST

Parameter Address = 51

Parameter Value   = 0.00240135192871094

Parameter Data :

0x00 ,    0x00 ,    0x4E ,    0xB0 ,   

 

Cell Name     = Level2
Parameter Name= SingleBandLevelDetwOutDisplay2ndGen5hold

Parameter Address = 52

Parameter Value   = 480

Parameter Data :

0x00 ,    0x00 ,    0x01 ,    0xE0 ,   

 

Cell Name     = Level2
Parameter Name= SingleBandLevelDetwOutDisplay2ndGen5decay

Parameter Address = 53

Parameter Value   = 0.000216960906982422

Parameter Data :

0x00 ,    0x00 ,    0x07 ,    0x1C ,   

 

Cell Name     = Level2_2
Parameter Name= SingleBandLevelDetwOutDisplay2ndGen6TCONST

Parameter Address = 54

Parameter Value   = 0.00240135192871094

Parameter Data :

0x00 ,    0x00 ,    0x4E ,    0xB0 ,   

 

Cell Name     = Level2_2
Parameter Name= SingleBandLevelDetwOutDisplay2ndGen6hold

Parameter Address = 55

Parameter Value   = 480

Parameter Data :

0x00 ,    0x00 ,    0x01 ,    0xE0 ,   

 

Cell Name     = Level2_2
Parameter Name= SingleBandLevelDetwOutDisplay2ndGen6decay

Parameter Address = 56

Parameter Value   = 0.000216960906982422

Parameter Data :

0x00 ,    0x00 ,    0x07 ,    0x1C ,

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