PIC Programming

Programming a micro controller has been in my mind for nearly a decade. I have done micro controller programming when I was an under graduate. That was for the 8080 processor. It is too big for small projects. I was looking for a suitable type of micro since there are couple of good ones PICs and AVRs. But I couldn't find any AVRs in the market but PICs are available for an affordable price. I bought two PICs, 16F877A and 16F84A, for Rs. 460/- and Rs. 320/- respectively.

The first step was to build a programmer (burner). I saw different types of programmers but thought of building a JDM type one. It has the advantage of operating without an external power supply and is much simpler to build. It takes power from the PC serial port. The disadvantage is, modern laptops cannot provide the required voltage level. Since most of the laptops (including mine) do not have a serial port, it has no effect.

Found the following circuit and built it on a vero board. It can program PICs upto 40 pins so there wont be any problem for a long time. (Full credit goes to the designer of the circuit, I just build his circuit)



This is how the final one looks like;



Then needed the software to connect the hardware to the PC. After reading many comments, I wanted to settle with IC-Prog. It is a great software which supports many types of programmers including the JDM. It also has a hardware test option to verify the hardware. Initially it didn't verify my hardware correctly and after so many sleepless nights, I found the bug. I have connected the Serial port incorrectly; more precisely, I have swapped the left hand side and the right hand side of the port. After rearranging, it worked like a charm.

I tested the programmer and the PIC using the famous "hello world" LED blinking program which ended quite successfully. Then I wrote a counting program using two seven segment LEDs with 16F84. Two segments are in multiplexed mode. The following video shows it in action.



These are my future plans with PICs.

- Build a clock with small digits (desktop clock)
- Build a wall clock with a big display
- Include the stealth mode to the clocks. i.e. it will retain its time when there is no mains power. I hope to use a real time clock IC like DS1307 or DS1302 with a battery backup.
- Include a thermometer function to the clock to display the room temperature. For this, I will use DS1820 IC.

Although I already have necessary hardware i.e PICs, clock ICs, temperature ICs (I got them from Dallas Semiconductors as samples), writing software takes a lot of time. Therefore it is impossible to figure out how long it will take to complete the above things. May be before next Christmas... :-)