DIY: 301 JTAG Cable

A JTAG is a cable that allows interface between a PC and another device.

The Joint Test Action Group is used as an integrated circuit debug port and boundary scanner. The integrated circuit is a computer chip that connects to other chips by inserting the IC chip into a computer board or plate. The 301 JTAG is a type of chip and the JTAG cable runs to a computer port, allowing the chip to interface with the computer. JTAG materials are sold by many different electronic supply retailers and can be made to connect the JTAG chip on a TV receiver, game box or other similar electronic device to the hard drive of a computer.

Things You'll Need

• Solder paste
• Soldering iron
• Box knife
• Heat gun
• Heat shrink tubing
• Seven pin heads
• Four-wire, 25-centimeter cable, 6 feet long

Instructions

1. Cut the 25-centimeter cables that come with the kit in half, making two different four-wire cables. Remove one of the bindings holding the four wires together on one of the cables. Peel away one of those wires, leaving three wires on one cable and leave all four wires on the other cable.

2. Remove the 4 inches of plastic surrounding all the wires, but leave the wires bundled at the bottom of all the wires. Take each individual wire and remove the 1/2 inch of insulation surrounding each wire. Place a drop of solder paste on the end of each exposed wire.

3. Cut seven pieces of shrink tubing, each 1 inch long. Push the shrink tubing over each individual wire. Slide a pin header over the end of an exposed wire. Solder the pin head onto the end of the wire. Push the shrink tubing over the soldered area and to the end of the pin head. Heat the shrink tubing with a heat gun to shrink the tubing around the pin head and wire. Repeat this step for each of the remaining wires.

4. Repeat step 2 on the other end of the two cables, exposing the wires. The pin head side of the cable will connect the JTAG cable to a pin port on the computer. The exposed wire side will attach to the 301 JTAG chip in your electronic device.

Tips & Warnings

• The United States allows you to modify the hardware on electronic devices and computers as long as you do not interfere with any property rights of the manufacturer or infringe on any intellectual property.

• You will not infringe on any intellectual property rights if you use the hardware modification for personal use and not to sell and make money.

• You can make any length of the JTAG cable, just buy longer 25-centimeter cable.

• Ensure the pin heads are securely soldered to the exposed wire before heating the shrink tubing.

• Safety must be taken when using a soldering iron. The head of the soldering iron gets very hot and can burn your skin.

References

• JTAG Cables: JTAG Cable - Simple JTAG Interface
• WRT54G Hacks: WRT54G Fundamentals
• TIAO: Make a Simple Nonbuffered JTAG Cable