Current Part:
MAX233A
7805 +5v Regulator
DB-9 Connector
Serial Cable
8x LEDs
16 MHz Crystal
10kΩ Resistor
Breadboard
Jumper Wire
SIPS
9v Connector
Desktp/Laptop
Parts List Details
Hopefully you are already familiar with most of the parts listed above. If not, don't worry, I've described the key components in more detail below. These are all the parts that make this system work.
PIC 18F4520
This is the main microcontroller that is used to receive and send RS232 serial commands for the circuit. It will also control which output LEDs are set when commands are received. You could call this the 'intelligent' part of the circuit. The PIC 18F452/18F252 can be substituted for the 18F4520.
MAX233A
This IC translates the digital +5v - 1's and +0v - 0's into the standard RS232 voltage levels. RS232 communication uses different voltage and current levels than 100% pure digital communication, so this translation step is necessary.
16 MHz Crystal
This is the frequency at which the PIC will run. The instruction cycle is actually Fosc/4 -> 4 MHz which is blazing fast as far as we are concerned.
+5v Regulator 7805
This regulator is used to maintain the +5v needed for the MAX233A and 18F4520 IC's. It is a good and simple 3 pin regulator.
DB-9 Connector, Serial Cable & Laptop/Desktop
The DB-9 connector makes it easier to connect the cable to the MAX233A's outputs so I recommend buying one, they're cheap too! Naturally, you will also need a laptop or desktop that has a serial port connection. A simple terminal program will be used to send/receive commands to the PIC from the Laptop/Desktop.