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Zero Error One Second Timer

Genom att använda våra tjänster godkänner du att vi använder cookies.Läs merOKMitt kontoSökMapsYouTubePlayNyheterGmailDriveKalenderGoogle+ÖversättFotonMerDokumentBloggerKontakterHangoutsÄnnu mer från GoogleLogga inDolda fältBöckerbooks.google.se - From cell phones and television remote controls to automobile engines and spacecraft, The value is determined as Value = Osc Freq / 4. 2.- Every timer0 overflow; subtract 256 from a 24-bits period variable, and; 3.- When period variable goes less than zero; where is my error? This is like my zero-error 1 second timing system, that uses a convenient constant to set ANY period (with 1 timer tick resolution).

The constant COUNT is the actual number you need. She earned a Ph.D. Note that original constant is 3096.25. It's too much to explain further here but is well explained by ROMAN BLACK on his webpage: http://www.romanblack.com/one_sec.htm The last 2 are period based free running timer methods using PR2 with

The DDS system below generates two combined (added) sinewaves as a single waveform, to generate DTMF with 2 combined sinewaves of very high accuracy frequencies. i will also post here again later, with another method of getting this number, without preloading TMR0, but better than the one which used Roman Black 2nd October 2007,07:08 #15 BlackOps The time now is 16:57. TIMER1 - Zero-Sum with Timer Stop Method Code: program RTC_Timer1_18F452 ' 24 Hour Real Time Clock - Zero-Sum Timer Stop Method ' mikroBasic 5.02 ... 18F452 @ 8MHz Default Configuration '

You don't even need a timer module. It only really needs an extra transistor to invert the signal for one FET. Use a high byte from the accumulator to reference position in a binary waveform table, load it in PWM 4. That way you can increment the easily increment the 16-bit quantity.

Feb 11, 2008 5,435 1,305 Hi, I've just updated my "zero error 1 second timer routines" page, there is a new section at the bottom that now supports zero-jitter period generation. The time now is 16:57. If I were forced to use Timer 0 for a RTC "heartbeat" instead of Timer 2, I might do it something like this (untested code); Good luck with your project. then i measured my final program and it did give 1.000.000 delay. 2nd October 2007,20:00 #16 BlackOps Full Member level 5 Join Date Jan 2005 Location AZERBAIJAN Posts 280 Helped 13

The first 2 programs utilize the Zero-Sum, or Zero Cumulative Error, method for maintaining accurate time. RB Thanks to ur Zero-Error and Zero-Jitter algorithm my clock works dead accurately. I also added a 0.47uF greencap (polyester cap) from GP2 to ground. Open-source - 21 Nov 2009 - www.RomanBlack.com/one_sec.htm PIC 12F675, 4MHz xtal.

TIMER0 - Zero-Sum Free-Running Timer Method Code: program RTC_Timer0_FreeRun_18F452 ' 24 Hour Real Time Clock - Zero-Sum Timer FreeRun Method ' mikroBasic 5.02 ... 18F452 @ 8MHz Default Configuration ' by This was based on my ZEZJ system for generating a frequency. This is the code that is easiest to use for most designs. All source-code will compile with the free demo version of the compiler.

Need to contact me? However this system has zero jitter! PIC assembler source code! Clock24 ' yes...then output End If Wend end.

The interrupt does nothing now, as the PWM period is automatic (every 100 instructions) and asynchronous to both the incoming and output mains frequencies. Author of BTc PIC-sound encoder, Shift1-LCD project, the TalkBotBrain talking PIC controller, LiniStepper open-source microstepping motor driver, the Black Regulator 2-transistor SMPS, and probably some other stuff; www.RomanBlack.com Mr RB, Nov They can make incredibly fine resolution freq output, but of course since that exceeds what is possible from the PIC timer it involves jitter. Accurate xtal-locked Sinewave inverter!

Register Remember Me? Zero Error Zero Jitter algorithm; (define PERIOD as the period to be generated, in TMR0 ticks) 1. Wait for sync with the PWM module (or interrupt) 2.

Note!

The issue with interrupts is the code overhead of saving important registers before getting to the programmer's interrupt code, such as reloading the timer and preparing for the next interrupt cycle. generate 1 interrupt of "remainder" length 100-199 3. This produces an exact 60Hz output which is mains-locked to the national 50Hz grid. can anyone say me why do i get such value?

Roman Black - PICs and electronics. It generates 1200Hz from the 120Hz input, by generating 10 "fake" events from each real 120Hz input event. Then at 4MHz, that would be your constant, 3096. bcf INTCON, TMR0IF swapf status_temp, w movwf STATUS swapf w_temp, f swapf w_temp, w retfie ;*********************************************************************************** ; END OF THE INTERRUPT SERVICE ROUTINE ;*********************************************************************************** ;*********************************************************************************** ; START OF THE SETUP ROUTINE

Clock24 ' yes...then output End If Wend end. + Post New Thread Please login Page 1 of 2 1 2 Last Jump to page: « sending data from microcontroller to a If you use the pre-scaler, which can be used either by TMR0 or by the WDT, then the calculation changes, based on the pre-scaler divider ratio, which you can select in The 2 PIC outputs are active HIGH, so when the PIC pin is +5v it turns on the FET.