ADAU1701 BCLK missing
Good day everyone,
I tried to configure an ADAU1701 DSP with Sigma Studio 3.15 to stream out an I2S signal.
That is my hardware configuration
and this the schematic
nothing complicated, but I can't get out any BCLK Signal from the DSP. I do see the Master Clock Signal with 12 MHz. The LRClock with 48 kHz and something that resembles DOUT data. But the MP11 the line stays low for all eternity. The RMS meters show movement when I connect an audio source to the analog Inputs, so I would guess that the audio singal is at least processed by the DSP. Still now BCLK output and therefore no sound form my external DAC. Has anybody an idea what I'm doing wrong right now that prevents the DSP from streaming out I2S Audio?
BR Chris
Audio Signal Processors
SigmaDSP Audio Processors
adau1701
Hello chrisk,
Well, I don't see a problem looking at your screenshots.
Are you using your own hardware? I would check the connection of MP11.
If you are using the Mini eval board then both MP10 and 11 go to LEDs so I would expect you would have modified the board by now.
With the circuit powered down, try using an ohm meter on the MP11 pin and see what kind of a load it is driving? Measure to ground and power. There may be a short somewhere.
You also could try to change the function to a GPIO output and see if you can drive it from the DSP and see some kind of signal. It is not likely that this one pin failed on the part for no reason. It is not a high current pin
You can send over your program and I can try it here and see if it works here.
Dave T
Hello Dave,
thank you for the feedback. I got the solution this morning. For some reasons yet unknown to me the write protect pin of the EEPROM was the issue. I've kept the WP line low all the time and this seems to affect the MP11 pin. The pin was not able to reach 3V, neither in GPIO mode nor while being used as BCLK. Upon removal of the WP connection the level is at 3V and the I2S output works as intended. Strangly this effects only the MP11 pin. MP10 and MP6 where working correctly even with the WP to GND connection.
BR Chris
Hello Chris,
The MP11 pin is pin 19 and the WB pin is pin 20. Seems to me you have a short on the PCB between pin 19 and 20.
So if this is true and you enable the WriteBack function, then the BCLK will be triggering WriteBacks constantly! That could certainly cause issue. So check for a short between the two pins.
Dave T
Had the same problem now solved.
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