Assembling the NKC Electronics JTAG ICE Clone Board (Rev. B)

Assembling the NKC Electronics JTAG ICE CLONE Board (Rev. B)

by NKC Electronics

SCHEMATICS (right click –> view image)

jtag schematic

JTAG ICE Clone board is an implementation of the Aquaticus JTAG ICE clone. The Kit includes the PCB and all the parts requiered to build a fully functional clone of AVR JTAG ICE. It can even be upgraded using AVR-STUDIO when a new firmware is released by Atmel.

This guide covers the assembly process of the JTAG ICE clone Rev B kit (marked Rev B in the PCB)

First, unpack the kit and start with the PCB.

The JTAG ICE clone board has all the component values printed on the PCB, making the use of the schematic almost unnecessary.

jtag ice clone kit

We will install the passive components (resistors, capacitors, etc) first.

jtag ice passive

Start by soldering the resistors R1 to R7, C3 to C9 ceramic capacitors, C10 electrolytic capacitor and D2 diode

R1 10 K resistor
R2, R3, R4, R6 1 K resistor
R5, R7 4.7 K resistor
C3, C4, C5, C6, C7, C8, C9 0.1uF ceramic capacitor
D1 1N4148 diode
C10 10uF electrolytic capacitor

jtag ice clone kit

Next identify and separate the 2 22pF ceramic capacitors, 2 LEDs and the crystal

C1, C2 22pF ceramic capacitor
Q1 7.3728 crystal

jtag ice clone kit

Now separate the 16-pin IC socket, 40-pin IC socket (wide), 10-pin male header, 5-pin male header, DB9 female PCB connector. Cut the 5-pin male header in one 3-pin header and one 2-pin header.

X1 DB9 female PCB connector
JTAG 2×5 male header
IC1 40-pin DIP socket
IC2 16-pin DIP socket
JP1 3-pin male header
JP2 2-pin male header

jtag ice clone kit

We are done with the soldering. You need to install the MCU and the RS232 (ICL3232, MAX3232, ST3232) driver in the sockets. The large chip is the ATMEGA16 Microcontroller. It is already programmed with the latest release of the JTAG ICE firmware, and the bootloader. Please, be very careful with the pins while inserting the ICs.

jtag ice clone kit

Insert the shunt shorting positions 2-3 of the 3-pin MODE header. The JTAG ICE clone board has two modes of operation:

  1. Programming / Upgrade mode
  2. Normal operation mode

Position 2-3 is the Normal operation mode (board is ready to connect to target board and start debugging)

jtag normal

Position 1-2 is the Programming mode. This mode is used to program or upgrade the JTAG ICE firmware. The firmware is distributed by Atmel with updates on the AVR Studio IDE. In the operation guide you will find the manual firmware upgrade process, explained in detail.

jtag program

This is how the JTAG ICE clone board looks ready to use with the 10-wire cable for the target board.
jtag ice clone kit

The target board must supply the power to the JTAG ICE clone board, using the standard JTAG connector. The board expects the power from the target board (2.7V to 5.0V) in the VTarget (VCC) pin. It is recommended to supply also the target voltage to the VTref pin (Use the provided JP2 and jumper to supply power to the board from the target device). The JTAG ICE board does not have voltage leveling circuit, so if you supply VTref, it must be the same as VTarget.

Testing the board:

  1. Start AVR Studio
  2. Verify mode jumper is in 2-3 Normal
  3. Connect JTAG port to target board. Supply VCC. At this point, you only need to supply VCC to the JTAG ICE clone board. No real circuit with target MCU is needed
  4. Both LEDs are on
  5. Select Connect to the Selected AVR Programmer avr studio connect
  6. You should see the following message: jtag avrstudio ocd error

This message means that AVR Studio detected the JTAG ICE clone board, but was not able to identify the target MCU (either it is not installed, or the installed MCU does not support JTAG).

The JTAG ICE clone board is now assembled and tested. Now you need a real target board to start debugging.

An important reminder: JTAG ICE requieres the JTAG fuse in the target MCU set: JTAG Interface Enabled [JTAGEN=0]. The setting looks like this in AVR Studio:

jtag avrstudio fuses

IMPORTANT NOTE to AVRStudio 4.13 sp2 users: There seems to be a bug in AVRStudio 4.13 sp2 that generates an error trying to read fuses using the JTAG interface. There is a fix posted in Atmel Norway website:

2 Responses to “Assembling the NKC Electronics JTAG ICE Clone Board (Rev. B)”

  1. John S. says:

    Great post man (or woman!)… Love your writing! Can’t wait to see more. Is there a subscribe feature here?

  2. Saroeuth says:

    I baught JTAG ICE Clone over a monther ago and still having problem. My computer com port no longer recognize JTAGE ICE CLONE anymore. It dected and found JTAG ICE CLONE a couple times that’s all. I tried six the different computers and still not work. I noted only the RED LED Lit not the clear LED. I replaced rs232 driver chip and still not work. Do you have any idea of what is wrong with this JTAGE ICE board?

    I thank you in advance if you can help me out.