I was intruduced to the PIC in Uni, where we programmed them initially with Flowcode, then with Assembly code (which I think is easier). I consider the PIC the best component ever to come in an 18pin DIP, and want one in my life!
I looked at buying a development board, then looked away when I saw the price! So I'm going to make one myself, I've done a few electronic projects before, how hard can it be?
I started with this design for a programmer: http://www.kmitl.ac.th/~kswichit%20/f84/f84.htm
And I've modified it to include a 3Mhz Xtal (the speed that boards in Uni use) with option for an external clock (so I can overclock the PIC one day). There is an LED and microswitch on each port.
Here is the design: http://img339.imageshack.us/img339/9853/programmerqz1.gif
Please do Poke holes, what concerns me the most is:
-My handling of the "NOT MCLR" pin, in Test mode the pin is kept at 5V and returned to 0V momentarily to reset the program?
-Powering the LED's directly off the ports, each LED and resistor draws 10mA at most, so I won't exceed the maximum current sunk through port A and B, even if all the LEDs are on at once, but If all this current has to originate at the Vss Pin (does it?) it's getting close to the 150mA limit, how much current can the Chip itself draw?
Feel free to poke any other holes.
As for software, I plan to Wite the Assembly code in Notepad++, then copy and paste it into WinPicProg ( http://www.winpicprog.co.uk/
) to compile this to a HEX file and write to the PIC.
Is there a free Simulator for the PIC16F84A, or a better free software solution?
Thanks in advance for your help.