May 7th, 2008
PIC16F84 Countdown timer for PCB exposure unit
The purpose of this timer is to provide a countdown time from 1 second to 99 minutes & 59 seconds. I use it to control the lighting for the Ultra-Violet exposure of photosensitive PCB material. The project provides also an audible alarm at the end of the countdown time and switches the UV lights by means of a relay. It is based on a Microchip microcontroller, the 18 pin PIC16F84(A). This microcontroller contains 1Kbyte of flash memory for program code, 64bytes of static RAM memory, and 64bytes of EEPROM memory which are used here to store up to 15 different (user-programmable) countdown times.
PIC16F84 Countdown timer for PCB exposure unit: [Link]
May 7th, 2008 at 9:25 pm
[...] The purpose of this timer is to provide a countdown time from 1 second to 99 minutes & 59 seconds. I use it to control the lighting for the Ultra-Violet exposure of photosensitive PCB material. The project provides also an audible alarm at the end of the countdown time and switches the UV lights by means of a relay. It is based on a Microchip microcontroller, the 18 pin PIC16F84(A). This microcontroller contains 1Kbyte of flash memory for program code, 64bytes of static RAM memory, and 64bytes of EEPROM memory which are used here to store up to 15 different (user-programmable) countdown times. [via] [...]
December 5th, 2009 at 7:42 am
instead of using a typical 555 timer, i am planning to make a programmbale timer using PIC 16F84A. can you help me about the codes? or can i see the code of this project so i can study.
December 5th, 2009 at 7:44 am
i’m gonna make three timers. but i don’t want to use a 555 timer. can i put it all in 1 PIC?
December 5th, 2009 at 11:54 am
for more info on the project you should follow the link at the end of the article, it will take you at the project page. I’m not sure if that PIC can handle 3 timers, it probably can but you’ll have to do some calculations on your on, or you can just pick a newer, more powerful PIC and try to do it.