| Re: ADC in Free Running Mode Kategorie: Programmierung C (von Torsten - 4.02.2013 19:38) | ||
| Als Antwort auf Re: ADC in Free Running Mode von PepeV - 2.02.2013 15:31 | ||
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> > > Hi Torsten, > > > > > > Im am afraid the other running modes you programmed do not work so well > > > as the free running mode. > > > - ADCaptureRun runs 15% slower than ADCaptureRunFree and shows some > > > glitches. > > > - ADCaptureRunQuiet shows strange behaviour. > > > See attached figures. What do you think? > > > > > > What might work is an 'ADCaptureRunFreeQuiet'. > > > > > > Regards, > > > Pepe > > > > Hi Torsten, > > > > The ATmega128 manual (p. 237) says ADC Noise Reduction mode is only possible > > in single conversion mode. So don't bother to try an 'ADCaptureRunFreeQuiet'. > > > > I now understand the reason for the $20 offset in SRAM addresses that is sometimes > > needed. Instructions in and out work on I/O registers and start counting from $00 (PINF). > > lnstructions ld and st reach all SRAM menory, including the working registers R0...R31. > > For these instructions R0 has address $00 and therefore the first I/O register has > > address $20. In CC-pro DirAcc_Read and DirAcc_Write also start counting from R0 so > > here I/O addresses also need an offset of $20. > > > > The CC-pro manual states 'An Assembler call cannot be interrupted by Multithreading > > or an Bytecode Interruptroutine'. Hello Pepe, but the cpu can do that. The so-called 'Bytecode Interruptroutinen' are not real Interruptroutinen. The real interrupt-functions are fixed functions. We unfortunately can not change these functions. Presumable, in these functions will be only a byte-variable increased. The bytecodeinterpreter checks occasionally this variables and calls your callbackfunction. That is the reason for your actual problem. >>This agrees with my observation that it does not > > matter wether ADCaptureRunFree begins with cli or sei. > > This also means that ADCaptureRun has no purpose since it cannot be interrupted. > > > > But I have a new challenge. My FFT routine needs its data in an array of float rather > > than in an array of word. Would it be possible to adapt ADCaptureRunFree to store > > its values in an array of float? I have searched internet for suitable chunks of byte code > > but I could not find any. Do you know a good source? > > > > Regards, > > Pepe > > Having browsed through the 'Beginners Introduction to theAssembly Language of > ATMEL-AVR-Microprocessors' I now think that it might be better and faster to > rewrite the FFT routine to work with integers than having ADCaptureRunFree > to produce floats. What do you think? Here's the FFT routine I use. > > Pepe I hope the author of this function understands also what he wrote. I wish you a lot of fun during debugging. In this function many divisions will calculated out. 'PI' also in not an integer value. I think with integer values the function becomes very inaccurate. I would recommend you for the first attempts a simple possibility. Just count the ramps or the waves. When you, however, would be insisting of a mathematical solution then we can go on with some Cordic. But don't say, I have not warned you! For the beginning I have collected some documents to read. GruÃ? Torsten FSKDemodulation.zip | ||
Antwort schreiben Antworten:  Re: ADC in Free Running Mode (von PepeV - 5.02.2013 13:27)Re: ADC in Free Running Mode (von Torsten - 6.02.2013 21:43)Re: ADC in Free Running Mode (von PepeV - 8.02.2013 17:43)Re: ADC in Free Running Mode (von Torsten - 9.02.2013 10:18)Re: ADC in Free Running Mode (von PepeV - 9.02.2013 14:57)Re: ADC in Free Running Mode (von PepeV - 11.02.2013 18:29)Re: ADC in Free Running Mode (von Torsten - 11.02.2013 21:07)Re: ADC in Free Running Mode (von PepeV - 12.02.2013 19:54) | ||
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