version 1, 2001/07/06
designed by Peter JAKAB
NOTE for beginners: PICs are general purpose microcontrollers which have to be programmed before you can use them in the actual circuit! Check out this link to learn more.
This is a simple one-valve irrigation controller made for our greenhouse. The code contains a software real-time clock (RTC) and a multiplexed 8-digit LED display and keyboard you can use in other projects.
The operating software is simple, it contains a real-time clock and a day counter. The valve is turned on in regular intervals in the same time. Day setting specifies the number of days between the activations, time setting specifies the time of the day when to start. Duration is the time after which the valve will be turned off.
The source code is freely downloadable. This is written for the PIC16F84, but you can easily adapt it to newer controllers like the 16F628 or OTP versions.
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|DIS0-DIS7||common-anode 8x1-digit or 4x2-digit 7-segment LED display|
|TR1||mains transformer, 1x220VAC, 2x12VAC|
|-||24VAC irrigation valve|
|K1||12VDC relay. Contacts: >=1A|
|Q1-Q10||10xBC547A or similar NPN bipolar transistor|
|IC2||PIC16F84 or PIC16F84A microcontroller, programmed|
|IC3||7805 voltage regulator with heatsink|
|AC1||diode bridge at least 80V/1A|
|F1||fuse 0.1A T|