Why dont you leave out the define, and specify the internal oscillator to rule out other variables? Then see if the circuit behaves as it should. Also, for PBP related stuff try posting on http://www.picbasic.co.uk/forum/ ; its a very active forum and has some real sharp sparks as well. Regards, Anand ----- Original Message ----- From: "Mark Wotton" To: "Microcontroller discussion list - Public." Sent: Monday, September 04, 2006 3:16 AM Subject: Re: [PIC] time-scaling problem with PIC 18F2455 > > On 03/09/2006, at 6:28 PM, Anand Dhuru wrote: > >> You have defined OSC 8; is the crystal actually 8? > > So my colleague assures me. I'm not using an external crystal - > there's a default oscillator on the board, isn't there? > (Again, forgive me my naivete, I'm new to this.) > >> If you dont define this (use the default 4 MHz) does the frequency >> double? > > Yes - as I mentioned, either setting it to 4 or leaving the OSC > declaration out gives 4 seconds per transition. > >> >> Also, the LED would be on for 1 second, and off for 1; the cycle >> would be 2 >> seconds. > > True: I was imprecise. It's currently on for 8 and off for 8, with a > cycle of 16. > > Mark > >> Regards, >> >> Anand >> >> ----- Original Message ----- >> From: "Mark Wotton" >> To: >> Sent: Sunday, September 03, 2006 7:46 PM >> Subject: [PIC] time-scaling problem with PIC 18F2455 >> >> >>> Hello, >>> >>> I'm trying to program a PIC 18F2455 chip. I'm using PicBasic Pro as a >>> frontend, MPLab v7.30 for the assembler, and MPLab icd 2 for the >>> programmer. A simple testing program to flash a light on and off at 1 >>> second intervals instead takes 8 seconds: >>> >>> ---------------------------------------- >>> INCLUDE "modedefs.bas" >>> >>> define OSC 8 >>> >>> TRISA=%00000 >>> TRISB=%00000000 >>> TRISC=%11111111 >>> >>> StatusLED VAR porta.1 >>> >>> LOOP: >>> high StatusLED >>> pause 1000 >>> low StatusLED >>> pause 1000 >>> goto LOOP >>> ------------------------------------------ >>> >>> If I change OSC to 4 (or leave it out), the program takes 4 seconds >>> per transition, so I initially thought I could just set OSC to 1 and >>> be done with it - this wouldn't compile in PicBasic Pro, however, >>> giving me the error "Symbol not previously defined (PAUSEUSL)". >>> >>> I tried fiddling with some of the constants defined in >>> C:\pbp\p18f2455.inc, which the generated assembly included: >>> -------------------------------------------- >>> INCLUDE "P18F2455.INC" ; MPASM Header >>> __CONFIG _CONFIG1L, _PLLDIV_5_1L & _CPUDIV_OSC1_PLL2_1L & >>> _USBDIV_2_1L >>> __CONFIG _CONFIG1H, _FOSC_HSPLL_HS_1H >>> __CONFIG _CONFIG2H, _WDT_ON_2H & _WDTPS_128_2H >>> __CONFIG _CONFIG3H, _PBADEN_OFF_3H >>> __CONFIG _CONFIG4L, _LVP_OFF_4L & _XINST_OFF_4L >>> --------------------------------------------- >>> >>> Unfortunately, nothing there seemed to have any effect on the timing >>> at all. Where do you suggest I look next? I'm at a bit of a loss. >>> >>> (It's important that the timing be right for this, as I need to use >>> serial comms to load new data at runtime, and SERIN doesn't seem to >>> want to work, even when I tried setting the baud rate on the other >>> end >>> of the serial to 1200 to compensate.) >>> >>> Please let me know if I've missed describing anything important, I'm >>> still quite new to PIC programming. >>> >>> Cheers, >>> Mark >>> >>> -- >>> A UNIX signature isn't a return address, it's the ASCII equivalent >>> of a >>> black velvet clown painting. It's a rectangle of carets surrounding a >>> quote from a literary giant of weeniedom like Heinlein or Dr. Who. >>> -- Chris Maeda >>> -- >>> http://www.piclist.com PIC/SX FAQ & list archive >>> View/change your membership options at >>> http://mailman.mit.edu/mailman/listinfo/piclist >>> >>> >>> -- >>> No virus found in this incoming message. >>> Checked by AVG Free Edition. >>> Version: 7.1.405 / Virus Database: 268.11.7/436 - Release Date: 01- >>> Sep-06 >>> >>> >> >> -- >> http://www.piclist.com PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist > > -- > I'm haunted by the freakish size of Nancy Reagan's head > No way that thing came with her body. > -- Mission of Burma, Nancy Reagan's Head > > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.1.405 / Virus Database: 268.11.7/436 - Release Date: 01-Sep-06 > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist