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PSoC 5, 3 & 1 MCU

Anonymous
Not applicable

Hello I am still trying to filter a signal. I had another problem but them solved. Firstly I am using ADC delsig after I am sending them to Digital Filter Block via DMA. My question is about ADC delsig output is signed integer. When I send them to filter to DMA, my signal get 2's complement form because DMA block allow to send 32bit unsigned integer . To solve them I add 1V DC offset from signal generator to test the code . My question is that can I solve it to another method because there would be problem to measure the my real signal. Anyone has an experience about that.

Thanks
Burak

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Esteemed Contributor II

I am not quite clear at which point of the signal chain your question aims.

   

signal at pin:GND to VDDA

   

ADC in: depends on selected reference

   

ADC out to Filter: signed integer

   

Filter out: signed int32

   

Filter to... ??? sram?: still signed int32

   

The DMA channel will not look at a sign and will transfer 32bit entities.

   

 

   

Bob

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Anonymous
Not applicable

My problem is due to DMA channels which send data from ADC delsig to Filter block. It's passing trought signed bit(adcdelsig) to unsigned bit(dma). A signal which is positive sign is not problem but converting negative sign become problem for me. I want to solve this. 

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Esteemed Contributor II

DMA is transferring data and there is no conversion between signed and unsigned.

   

 

   

Bob

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Anonymous
Not applicable

Yes you are right, I was looking the DAC output. Thats my wrong. Now everthing is clear for me. Thank you and sorry for blank topic. 
Burak

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Esteemed Contributor II

The DAC is only 8 bits wide and is unsigned (uint8) to convert a signed int8 into a uint8 just add 128.

   

 

   

Bob

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