Fuzy Logic Wash Machine circuit using PIC16F84

Timing sequence like the above description, can be implemented with many way, by using discrete electronic components, timer, using a program or a microcontroller or microprocessor, etc. Because I am learning the PIC microcontroller for right now, I will implement this function using this microcontroller, but for you who familiar with another kind of microcontroller my adapted it to your purpose. By using PIC micro, it can be made more compact. First I plan to make 2 buttons, 1 for set the timer and another for reset the timer or for the emergency stop push button. Then to know the timer works or not, I need a visual display. For this purpose I will use 7-segmen display showing the rest of the timer. To run the motor sequence of course I need a pair of relays (power relays, about 3 Amperes output), one for forward and another for reverse option. I will use the very common family of PIC micro, ie : 16F84A, because this is the most popular type and very simples used and very much used. Also can be obtained easily in the market. But this is the medium type of PIC micro family. It has 1kByte of memory (EEPROM type) and 13 I/O pins. It can be reprogrammable thousands times. Because the I/O just only 13 pins, I used a BCD to 7-segmen chip. So it will left a few I/O pins for expanded in the future. You can omitted this chip for timing sequence purpose and save one IC price, because the I/O just exactly enough.



source:http://www.dsaprojects.110mb.com/electronics/timer/washing_mc.html