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.The source code is freely downloadable. This is written for the PIC16F84, but you can easily adapt it to newer controllers like the PIC16F628 source

This is a lamp timer capable of operating two separate relay switches. Outputs can be in three (or restricted to two) states: OFF, delayed ON and constant ON. Delayed ON mode is indicated by the LEDs. The source code is easily customizable for your needs: set your desired delay time or disable constant ON state.source

The circuit starts timing when switched on. The green LED lights to show that timing is in progress. When the time period is over the green LED turns off, the red LED turns on and the bleeper sounds.The time period is set by adjusting the variable resistor. It can be adjusted from 1 to 10 minutes (approximately) with the parts shown in the diagram. You can mark the times on a scale drawn on the box.source

This is a simple timer that switches off it’s own mains power supply when the load is switched off.The on time is set by the RC-time of a resistor and an elcap in combination by a schmitt trigger CMOS gate. Practical on times of 10 seconds to about 30 minutes can be archived. The timer concept is not very accurate, but once set, the on-time of the circuit proved to be quite stable. source

The ARDF controller was created after a request to be able to play random audiofiles for an ARDF transmitter, most existing designs were based on an PIC16F84, a somewhat aging design and better controllers are currently available. Also most controllers had a 5-10 mA current drain which can be improved, this design requires less than 400 uA.. To allow a very small controller footprint and flexible configuration the timer is not configured with (dip) switches but via a serial connection and a host PC.source