Introduction: Business Card PIC Programmer

This was my entry for the Hack A Day business card size circuit contest. I just zipped up the files and put them on my website. I'm posting it here because all the other entries seem to be on a blog for easy access. Hopefully this will make the project more accessible and reduce the load on my server.

The attached archive is the contest entry as it was on my server, minus the images. The text is taken from the included document.

This PIC/EEPROM programmer is so simple and small it fits on a business card with enough room left for assembly instructions...

Simple JDM2 style PIC ICSP programmer (on a business card).
  • all through hole
  • less than 2USD worth of parts (in 1s and 2s!)
  • easy single sided construction at home (with 3 jumpers)
  • enough room left for assembly instructions
  • extra space on the back for even more business-cardy goodness
  • also programs/reads serial EEPROMS
Skill level:

Assembly time:
About an hour.

Step 1: Description

Anyone can build this simple programmer and learn about PIC microcontrollers. The JDM2 programmer is super simple (about 10 parts), but programs a huge variety of PICS and serial EEPROMs. I've programmed everything from an 8 pin 12F629 to a new 18F4550 USB PIC with the JDM2. This programmer has an ICSP interface, meaning it can program PICs and read EEPROMs while they are attached to a circuit board. Start your hacking!

The PCB can be made single sided (with three jumper wires), but a two layer design makes assembly even easier. All the traces are nice and fat for easy toner-transfer or photo-process at home.

The JDM2 design is quite old, the original JDM2 circuit can be found here:

This design stays true to the old schematic, but the diode numbering now starts at 1, rather than 2.


Step 2: Parts

Part Value Description

C1 100uF/16 volt electrolytic capacitor
C2 22uF/16 volt tantalum capacitor
D1 8.2V zener diode
D2 5.1V zener diode
D3,4,5,6 1N4148 diode
Q1,2 BC547B transistor-npn
R1 10K resistor
R2 1.5K resistor
SV1 5 pin header pin header (or female pin header, you choose)
X1 DB9 female serial connector

Step 3: Assembly #1

Start from the bottom and work up:
Don't forget to begin with the jumper wires if you are using a single sided PCB.

  • Solder the diodes and resistors.
  • Each diode has a black band that should be oriented in the same direction shown on the board/in the schematic.
  • Just solder in the resistors, no special orientation required.

Step 4: Assembly #2

Next, add the transistors. They should be oriented at show in the schematic/picture. The transistor on the left is placed in the direction opposite the transistor on the right (notice both have round parts facing the middle). This is the standard (typical?) BC547B pin-out. If you have problems with your finished circuit, make sure that your transistors have the same pin-out as shown in the schematic and reorient as needed.

Step 5: Assembly #3

  • Finish the board by soldering the tallest components: the capacitors, pin header, and DB9 socket.
  • The electrolytic capacitor should be soldered with the ground, indicated by the black stripe, facing the left side (as shown in the picture). If thats a bit confusing, make sure that the lead coming from the side with the black strip connects to the ground plane (the large copper area covering the majority of the board).
  • The tantalum capacitor should be placed with the ground towards the right of the board (as shown in the picture). Tantalum capacitors might indicate the positive lead with a +, rather than the ground lead (as with the electrolytic capacitor). As with the electrolytic capacitor, the ground attaches to the large ground plane that covers the majority of the board.

Step 6: Use

The programmer will work with any programming software that supports the JDM2. I like WinPic800 because it can auto-detect many PICs. WinPIC also deserves credit for the great technical support info WinPIC. Both support the newest USB PICs (18F2/4455). ICProg does many PICs, as well as EEPROMs, but has not been updated in awhile ICProg.

ICSP Overview:
Quoted from my ICSP instructable here.

Understanding ICSP for PIC Microcontrollers
Programming microcontrollers isn't hard. Building a programmer makes a great first electronics project. The goal of this section is to explain the simple 'In Circuit Serial Programming' method used with Microchip PICs.

Programming a big DIP (through hole) chip is easy. Pop it into a socketed programmer, burn, and return to the application circuit. Test and repeat.

Things get more difficult with smaller (surface mount) chips. There are no standard sockets for QFN, SSOP, QFP, or even the large SOIC .300 packages. There are really expensive ($100s) clips that can attach to, and program, these chips. A different clip is needed for each chip type and pin count you use.

There is an alternative. Its called ICSP.
ICSP means 'in circuit serial programmer(ing?)'. It is a way of programming a PIC while it is still attached to the application circuit. Thats right, no more chip swapping.

So, why is ICSP a good thing?
1. There are no programming sockets for small package chips. Clips are expensive.
2. Its a pain to move chips in & out of the programmer during development. Impossible for surface mount parts.

Read the rest.