Different reading STM32F4 + adau1452 SPI of DSP readback block

Hi

I think you will find that the Hex View is just a representation of the Actual 8.24 Value

Thus 1 represented in 8.24

So the return bytes looks OK

Thanks

hi Brettcoupe, thanks for the reply but how to convert 0x01 0x00 0x00 0x00 to 0x00 0x00 0x00 0x03?

what is the relationship?

termite showing the value of 0X001D block but i want it and expect it to show the value of 0x001A block base on the SPI program code.

tag: KJBob

thanks

Hello Kal,

The Capture Window is showing the same "0x 00 00 00 03" result as does the Readback cell in your schematic, which is good. What's strange is that both aren't showing the actual value of the DC Source, which is 0x 01 00 00 00. When I try this readback here, the results show 01 00 00 00 as expected:

From here it's hard to tell why the DC Source and / or Readback block in your project are behaving this way. Try saving a copy of your project, then delete from the copy everything except the source and readback cells -- then try the readback again. Or download and run the simple project I attached below, which should give the same results.

Best regards,

Bob

thanks KJBob for your insight,

maybe i assume the signal wires were too long that make the reading wrecked.... since if i connect the header directly to the eval board then the reading of readback block is ok ( 0x 01 00 00 00)

i will just proceed to design the crossover board containing adau1452+stm32 and i hope in future they wont give me problem since the signal traces in the PCB are short.

thanks and regards,

kal

Hello kal,

Your leads were too long. Plus, you should try to include a ground wire wrapped with the data wires for impedance reasons. There are other variables here but your tests seemed to have proven that it is the length of the cables.

Dave T