Electronics Component Kit by NKC Electronics

April 22nd, 2016

The Electronics Component Kit (ECK) is ideal for electronics beginners looking to experiment with all sorts of components and experienced engineers looking to replenish his/her stock of components.

The kit includes:

Component Quantity
Plastic Box 1
Electrolytic Capacitor (4.7uF, 10uF, 47uF, 100uF, 220uF) 5 pcs each value
Jumper Wires, pack of 65 1
Breadboard 170 PTS 2
Speaker 0.5W 8ohms 1
NPN Bipolar Transistor S8050 5
PNP Bipolar Transistor S8550 5
NPN Bipolar Transistor S9013 5
PNP Bipolar Transistor S9012 5
Round Magnet 1
Ceramic Capacitor 50V (0.01uF, 0.1uF, 1uF, 0.047uF, 0.47uF) 10 pcs each value
Red LED 5
Yellow LED 5
Green LED 5
White LED 5
White Straw Hat LED 5
Red Straw Hat LED 5
Green Straw Hat LED 5
Blue Straw Hat LED 5
Diode 1N4148 10
Reed Switch 1
Photo Resistor 1
Thermistor 1
Buzzer 5V 1
7-segment LED display (Red) – Common Cathode 1
Potentiometer with knob 1
Resistor 1/4W 5% (100, 470, 1K, 4.7K, 10K, 20K, 47K, 100K, 200K, 510K, 1M) 10 pcs each value
74HC595 IC 1
IRF520N N-Channel MOSFET Transistor 1
LM386 Audio amplifier IC 1
NE555 timer 2
CD4026 7-segment driver 1
Microphone 1
Push Button 50mA 5
2032 Battery Holder 2
Parts List 1

We will be publishing more information about each component and example projects.

Assembling the JN5168 module breakout PCB KIT

September 14th, 2015

We designed a breakout PCB for the JN5168 module. It works with JN5168-001-Mxx modules.
Current PCB is version 2 and has a bug on the FTDI pinout (RX and TX are reversed). Please do not use the FTDI header to plug the FTDI cable or adapter directly. (Purchase here). If ever you need rf material for PCB or other pcb materials you can order online from any pcb shipping companies and they will immediately ship one for you.

What is included:

  • JN5168-001-Mxx module breakout PCB version 2
  • 1 330ohm resistor
  • 1 3mm LED
  • 2 1K resistors (optional to pull-up PGM and RESET pins)
  • 2 tactile switches
  • 2 male headers
  • 1 6-pin female header for the FTDI port (RX and TX pins are reversed on this PCB version, do not plug FTDI adapter directly)

Step 1: remove content from bag

JN5168 breakout module KIT

Step 2: solder the JN5168-001-Mxx module to the PCB. Use enough soldering flux and a fine soldering tip. Align the 3 sides of the module with pins correctly on the PCB before soldering the first pin. After you solder the first pin, you can solder the rest as the module will stay in place.

JN5168-001-Mxx breakout PCB

soldering the JN5168-001-Mxx module to the breakout PCB

Soldering the JN5168-001-Mxx module to the PCB

Step 3: solder the resistor and LED. The LED has a positive and a negative pin. Positive pin is longer than the negative pin. Place the negative pin in the hole close to the R2 resistor and the positive pin towards the PGM switch. We have not marked the positive pin on this version of the PCB. The resistor for the LED is one marked 330ohms and it goes into the spot marked as R3. We are including 2 1K resistors if you want to pull-up the PGM and RESET pins (R1 and R2) on the JN5168 module. This step is completely optional and programming works just fine without these resistors.

Soldering the LED and resistors to the PCB

Step 4: Solder the tactile switches. One switch is for RESET and the other one is to place the module in programming mode while resetting. We will include a brief description on how to reset the module and put it in programming mode at the end of this blog.

soldering the tactile switches to the PCB

Step 5: Solder the headers. One side has 14 pins and the other side has 13 pins. The JN5168 module has in total 27 pins and we exposed all of them in this PCB. We are also including a 6-pin female header for the FTDI header. In theory, you could plug an FTDI cable (3.3V version) directly or an FTDI basic breakout from Sparkfun, but there is a BUG that reserves the RX and TX pins.

soldering the headers to the PCB

And here is the picture of the assembled KIT

Assembled KIT

How to put the module in programming mode: The JN5168-001-Mxx module goes into programming mode if you hold the SPIMISO line (pin 3) LOW while you reset the module. In this breakout, you just press both tactile switches, then release first the RESET switch and about 1 second later, release the PGM switch. The module is now in programming module and it should be recognized by the Flash Programmer or the programmer included in the JN5168 development software. After programming and verifying the flash, you need to reset again the module to start running the new firmware, but this time just press and release RESET or power cycle the breakout board. If you press the PGM switch again, it will go again in programming mode and not running mode. 

Apple II Address LED Display using the Prototyping and Debugging Board

July 4th, 2015

I created an Apple II Address BUS LED Display using Prototyping and Debugging Board for Apple II. The Display is based on an old document I found with schematics for the Address BUS LED display and single stepping for 6502.


For the Address LED Display

1 x NKC Electronics Apple II Prototyping and Debugging Board
16 x Red 5mm LED
1 x Blue 5mm LED (for SYNC display)
17 x 100 ohm resistor
4 x 100nF ceramic capacitor
3 x 74LS174 (we are using 74ALS174)

For single stepping circuit

1 x 74LS74 (we are using 74ALS74)
2 x SPST switch
1 x SPDT momentary switch
1 x 270 ohm resistor

So far, I’ve built only the Address LED display and it works very well. I still need to test the single stepping circuit, as the schematics I found is very old and the SYNC signal from the 6502 microprocessor is not available on the Peripheral bus.

Update (04-Sep-2015): I found out that the SYNC signal from the 6502 microcontroller is available on the Peripheral slots on the Apple //e, so today I implemented the single step circuit and it works great. It has the option to do single cycle or single instruction. A second switch is used to define if Apple //e is running continuously or single stepping and a momentary push button is used to do the single stepping. I also connected the BLUE LED to the SYNC signal.

Update (14-Sep-2015): Schematics for the Address Display and Single Step circuitry. It was extracted from the Apple I manual. Single Step uses only one 7474 IC, one resistor and 3 switches… it shows Steve Wozniak’s genius design skills. I found a similar schematics from the 6502 team and it is way more complex.

6502 Single Step and address display schematics from Apple I manual

Assembling the breadboard power supply dual 5V and 3.3V

July 3rd, 2012

Modern microcontroller projects require the use of multiple voltages to combine different parts. It is very common to prototype circuits that require both 5V and 3.3V (i.e. Arduino projects that use sensors or micro controller boards like chipKIT that interface with 5V devices, etc).

We created a breadboard power supply stick that provides both 5V and 3.3V. The voltage selection is user selectable, so you can power both power buses on a breadboard with same 5V, same 3.3V or mix 5V and 3.3V on the different buses.

The product comes fully assembled, except for the male headers that are provided unsoldered. Breadboards are slightly different in size, so doing the final soldering we can assure you have the best fitting product to your specific breadboard. Differences are tiny, but you can find the best fit doing the final soldering.

First, unpack the kit


Start by breaking the male header

  • 5 x 2-pin
  • 2 x 3-pin


Insert 2 2-pin male headers on one of the power bus, then insert 2 other 2-pin male headers on the other power bus.


Insert the power supply stick matching the 8 pins to the 8 power holes and solder


Solder the 2 3-pin voltage selection headers, then place the jumpers based on your voltage needs. Plug a 7 to 12V DC supply to the 2.1mm barrel jack and you will have a working breadboard power supply stick.


Assembling the NKC Electronics XBee Shield V4.0 KIT

November 1st, 2011

Assembling the NKC Electronics XBee Shield V4.0 KIT

SCHEMATICS (click on images to enlarge)
xbee shield v4.0 schematics

The NKC Electronics XBee Shield V4.0 KIT is an enhanced version of the original Arduino XBee Shield. It is sold in a DIY kit format and it comes with all the components required to assemble a full XBee Shield that is pin-compatible with all Arduino format compliant boards (Arduino, Freeduino, Seeeduino, chipKIT, etc).

V4 includes some new features, like a switch to select XBEE or USB instead of jumpers. This switch, re-routes RX and TX at the same time, so if for some reason, you still need to switch RX to one position and TX to the same position, then solder a 2×3 male header instead of the provided switch, and use jumpers to select the position you need.

First, unpack the kit

Xbee Shield V4.0 KIT

and start with the PCB.

Let’s start with the power section and the switches of the schematic using the following parts:

IC1 LD1117-33 Voltage Regulator (TO-220 package)
C1 100nF ceramic capacitor
C2 10uF electrolytic capacitor
reset tactile switch (4 legs)
XBEE/USB DPDT micro switch (6 pins)

xbee shield v4.0 KIT

Next continue with the transistor, LEDs and resistors:

xbee shield v4.0 KIT

R1 10K resistor 
R2 15K resistor 
R3 1K resistor 
R4 330ohm resistor 
R5 18ohm resistor 
RSSI 3mm LED yellow
ASSOCIATE 3mm LED blue (transparent)
T1 BC547 transistor

Solder the sockets and pin headers:

xbee shield v4.0 KIT

Next step: Insert the jumpers and the board is completely assembled:

xbee shield v4.0 KIT

There are 2 jumpers. J1 and J2 are for upgrading the firmware on the XBee module. Leave open for normal operation (both J1 and J2 open).

The XBEE/USB switch is used to route the RX and TX signals from the XBEE module to the Arduino board.  Select XBEE position if you want to communicate the XBee module with the ATmega chip on the Arduino (or compatible) or PIC on the chipKIT board.  Select USB if the board does not have the microcontroller installed and you want to use the USB interface to communicate the PC directly to the XBee board.

And this is the final picture of the XBee Shield V4.0 assembled and ready to use. XBee module is not included in the kit and must be purchased separately.

xbee shield v4.0 KIT