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.

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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.

1 Person Made This Project!


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146 Discussions


4 years ago

I was wonder of you knew how to program reward / loyalty cards?


6 years ago on Introduction

Hi guys, im trying to make this on a budget. The clad boards seem a tad expensive, and lots of labor in making it. Bottom line is i was going to make this on a piece of cardboard or something similar.

I have a question however how exactly do grounds work on circuit boards? Ground is just a piece of metal that all componets requiring ground need to touch to? Does this ground require anything outside of that, for example the DB9 is that grounded to the PCB ground as well, and in turn does the DB9 somehow ground the PCB to the computer?

In otherwords is there anything special i need to do because im using cardboard instead of clad?

Lastly i noticed an explosion warning in the document and placing a diode between the programmer (this pic programmer i assume) and the system (the computers DB9 i assume), just for clarification where exactly do i put this diode and why wasn't it simply put into the PCB design? I assume this is in regards to just programming a pic. I also see mention of master clear and a resistor, i assume the resistor isn't needed unless i need to clear the pic due to some error programming it.

Anyways im obviously a noob just getting my feet wet so could use a bit of help


6 years ago on Introduction

Hi. First off, thanks to Ian for a great Instructable. I have just constructed this circuit and am trying to do the hello world of PIC programming (The lit LED). this is my first attempt at PIC programming and Im fairly new to electronics also.

The circuit seems to be constructed properly, I am using a desktop tower with COM1 port and under Linux, running the command line version of picpgm. Picpgm autodetects it as a JDM programmer and I tell it to read the PIC to verify if it is blank or not. I get an error

"picpgm: /home/christian/picpgm_1751/picpgm/src/common/pic10fxxx.cpp:640: virtual UINT32 CPic10Fxxx::GetOSCCAL(): Assertion `(m_nOSCCAL & 0x0F00) == 0x0C00' failed."

I then went back and measured the voltage across the VSS pin and VPP pin whilst it is trying to program/read the PIC, It was 15.2V, quite high considering most people seem to report problems where they have too low a voltage here.

BUT; then something very odd happened, whilst I had the multimeter pressed against the VSS and VPP pins, measuring the DC voltage, the programmer worked!! I was able to read the chip, what's more, I was actually able to program the chip (as long as I had my multimeter leads testing DC voltage between VSS and VPP throughout?!).

Does anyone have any idea why that might be? I thought it might be impedence, so tried a variety of 10M, 1M, 100K 22K resistors across VPP and VSS but that did not recreate the same effect as using the multimerer. Can anyone hazard a guess as to why my VPP voltage is also so high?

The only difference to Ian's schematic is that for some reason I ended up with a 5.6V zener diode in mine as opposed to a 5.1V zener. I didnt think it would make that much difference to the voltage though. I also have an LED between D1 and Q1 to show when it is programming. Many other JDM circuits also have this LED in them so i didn't think it was a big deviation from the design.

Any help appreciated. Thanks in advance, sorry for the length.


6 years ago on Introduction

I want to program PIC12F629 with readymade .hex code. Which programmer should I use? I would like to know the best and cheapest programmer available. I bought PICKIT2 clone from India but I had very bad experience with it. I couldn't program with it.
Can you please suggest me good programmer?

No clue what a PH4148 is, but when googeling it all I get is that it is a Zener Diode, and in that case, NO it will not work.
Do you have the datasheet for your diode?

You could use 1n4007 or similar diodes though.. what else have you got?

The most easiest Programmer i have found after researching!
Im not an expert in electronics, but i just want to Program PIC10F200 and PIC12F629, for an InfraRed Controlled Airplane.
Could you please tell me How to Connect the DB9 Cable to Laptop? My laptop doesnt seem to have a DB9 connection, not even my desktop computer.
I have a 15 pin connection. How to connect it?? Thank you.

1 reply

Well if your laptop doesnt have a DB9 connector, obviously you need an adapter. Look for a USB to Serial adapter.


7 years ago on Step 6

i'm starting muc world. and will start with this project. Did anyone test this project?


8 years ago on Introduction

Hi there, where have all the pdf's gone. I wanted to download the circuit to print it.


8 years ago on Step 2

Hi there, forgive me but I'm new at electronics and I'm scratching the surface right now. Having said that, what is this used for? What is a PIC controller. What can you do with the device you built? Thanks very much and sorry for my lack of education.

1 reply

8 years ago on Introduction

Will this programmer work with all PIC's? I need to program a PIC16F684.


8 years ago on Introduction

I built a programmer off of your schematic and it works great. Thank you! Now I can program newer PIC microchips without buying an expensive programmer.


8 years ago on Step 2

How would I go about making this a usb programmer.

Thanx in advance,

1 reply

Reply 8 years ago on Introduction

You can take this JDM programmer and load a bootloader program into a PIC with USB capabilities. Wire up the USB and use the bootloader program to load programs to the PIC over USB


8 years ago on Step 2

can i use a 2N2222 NPN transistor instead of the BC547B?