Post by thread:[PIC]: Digital Alarm Clock source code and schemat

Hi! I like to build a digital alarm clock using PIC 16F84, the display format must be Military time. The following problems are: 1. A certain website discuss about PIC 16F84 timer. The 1 second delay well not be exactly 1 second because of the error. How can I made an error correction with this? 2.Can I set an interrupt (ISR)? for the setting of the alarm time. 3.Is there anybody can share me a simple Digital clock schematic using PIC 16F84. Thanks in advance... Best regards, -=jug=- / / Homepage: ( ,),) http://juggernut.cjb.net ( +++) Email: > < spam_OUTjuggernutzTakeThisOuTyahoo.com /^ ^\ .....juggernutKILLspam@spam@crosswinds.net ^ ^ imceceKILLspamcrosswinds.net just hoping that your okay!!!

On 2 Jun 00, at 21:49, -=jugggernut=- wrote: You may found a collection of all clock I found on the web based on to 16F84 and my own one at: http://www.geocities.com/vsurducan/pic.htm Take a deep breath and look at every one... {Quote hidden}> Hi! > > I like to build a digital alarm clock using PIC 16F84, the display format > must be Military time. > > The following problems are: > 1. A certain website discuss about PIC 16F84 timer. The 1 second delay well > not be exactly 1 second because of the error. How can I made an error > correction with this? > > 2.Can I set an interrupt (ISR)? for the setting of the alarm time. > > 3.Is there anybody can share me a simple Digital clock schematic using PIC > 16F84. > > Thanks in advance... > > Best regards, > > -=jug=- > > / / Homepage: > ( ,),) http://juggernut.cjb.net > ( +++) Email: > > < .....juggernutzKILLspam.....yahoo.com > /^ ^\ EraseMEjuggernutspam_OUTTakeThisOuTcrosswinds.net > ^ ^ imcecespam_OUTcrosswinds.net > just hoping that your okay!!! ********************************************* Surducan Vasile, engineer mail: @spam@vasileKILLspaml30.itim-cj.ro URL: http://www.geocities.com/vsurducan *********************************************

Hi Microchip has got a chematic with code. Follow these links: LCD Clock: www.microchip.com/Download/Appnote/Category/16CXX/00582b.pdf http://www.microchip.com/Download/Appnote/Category/16CXX/00582.zip 7SEG LED Clock on 32768Hz Crystal: www.microchip.com/Download/Appnote/Category/PIC16/00615b.pdf http://www.microchip.com/10/Appnote/Category/PIC16/00615/indexZIP0.htm I want to mention that I am building a "CountDown" timer, and I use the following method to acurately time the seconds: 1. I run the PIC from a 4.194304 MHz Crystal. 2. The PIC then performs 1048576 Instructions per second 3. I set up the Timer Overflow Interrupt with a prescaler of 16 4. The Timer Interrupt then occurs 256 times per second 5. My ISR Increments another counter I defined 6. When that counter overflows from 0xFF to 0X00 (and sets the carry bit), I know exactly one second has passed, and I update my seconds, minutes, hours counter accordingly and update the display. Try this. I hope it helps Regards, Werner Soekoe Information Systems Manager Free State Legislature KILLspamwernersKILLspamfsl.gov.za Tel. (051) 407-1109 Fax. (051) 407-1137 Cell. 082 376 8383 Country Code. +27 {Original Message removed}

I would be tempted to use one of the 8pin RTCC (real-time clock/calendar) chips. Would give good accuracy and only need 2 i/o pins leaving plenty for display drive. since freq is only 32K, you can drive PIC and RTCC with this crystal and save on power too. John Mullan {Original Message removed}

Hello -=jugggernut=-. I've been working on a not too dissimilar project with ke Neehr RemoveMEneehrTakeThisOuTswipnet.se , so I can possibly help you with code. You might just ask him if he minds if I give you the code. > 1. A certain website discuss about PIC 16F84 timer. The 1 second > delay well not be exactly 1 second because of the error. How can I > made an error correction with this? I'm not sure what sort of error you mean. Care to explain? I have coded the clock to work with no error using a 4 MHz crystal. > 2.Can I set an interrupt (ISR)? for the setting of the alarm time. You don't need *any* interrupts for this project. Not only do you not *need* them, you will find them a great hindrance. -- Cheers, Paul B.

Hello -=jugggernut=-. I've been working on a not too dissimilar project with ke Neehr spamBeGoneneehrspamBeGoneswipnet.se , so I can possibly help you with code. You might just ask him if he minds if I give you the code. > 1. A certain website discuss about PIC 16F84 timer. The 1 second > delay well not be exactly 1 second because of the error. How can I > made an error correction with this? I'm not sure what sort of error you mean. Care to explain? I have coded the clock to work with no error using a 4 MHz crystal. > 2.Can I set an interrupt (ISR)? for the setting of the alarm time. You don't need *any* interrupts for this project. Not only do you not *need* them, you will find them a great hindrance. -- Cheers, Paul B.