WiFi-enabled Color LED Matrix using ESP8266 and WS2812 LEDs

Last Thursday I had a lot of fun doing a workshop at my college (UMass Amherst) where I taught students to use a WiFi-enabled Color LED matrix combined with Javascript programs to create animations displayed onto the LED matrix. The matrix is made of 5×7 WS2812 (NeoPixel) LEDs. I’ve actually designed it two years ago and wrote a blog post about it. Back then I was using an Arduino-compatible SquareWear Mini to control the display patterns. It was fun to play with, but changing the display patterns require modifying the Arduino sketch and upload it over and over again, which took a lot of time.

This time, I improved the design by simply using a ESP8266 WiFi chip mounted at the back of the LED matrix. I wrote a firmware with a minimal set of HTTP GET API, with which you can set all pixels colors, set the brightness, or tell it to scroll a line of text. What’s cool about it is that you can now use Javascripts to send animation frames to it on the fly, which is a lot easier compared to re-writing and uploading an Arduino sketch. In addition, you can take the LED matrix on the go and use your mobile phone to control it, which is nice for wearable electronics.


The video below goes through the details. Take a look at it first. Essentially, combining ESP8266 with the LED matrix makes a little wireless display. The next thing I should work on is to figure out how to stream video to it. It’s going to be very very low resolution for sure, but it’s gonna be fun, and I can always daisy chain multiple matrices to make a larger display.

Workshop Materials

Below you can download the materials I prepared for the workshop, including the Arduino firmware code (compilable in Arduino using ESP8266 core with NeoPixel library), the Javascript programs I wrote, and the powerpoint slides with lots of details and can be used as a 1-2 hour tutorial.

Also, the LED matrix and ESP8266 development board that I used in the demo are both designed by myself. They are attached together by double-sided tape and three soldered wires. The hardware design files are available in my Github repository below:

Sneak Peak Preview of SquareWear Esimal

Since SquareWear 2.0 and Mini, there will soon be a new member in the SquareWear family. This is a sneak peak preview of SquareWear Esimal — the tiniest SquareWear ever made ๐Ÿ™‚


How does it differ from the other two members? First, it’s tiny and measure only 1.1″ x 0.7″. It’s designed to be small, low-cost, and suitable for breadboard experiments. It has two rows of 1×11 0.1″-pitch pin headers and can fit directly onto a breadboard. Second, it uses a micro-USB connector, which helps reduce the overall footprint. Although the big sewable pins are gone (so are the built-in buzzer and rechargeable battery), the Esimal keeps the most essential features of SquareWear — it has ATmega328 running at 3.3V, 12MHz, with built-in USB port and USBasp bootloader, light sensor (using a photoresistor), temperature sensor (using a thermistor), general-purpose button, and LED. Overall it will be a very low-cost, breadboard friendly SquareWear, for learning Arduino programming, organizing workshops, and general-purpose microcontroller projects.


Since this post is a preview, I will not dwell too much on the details. Expect Esimal to be available in a few weeks time!

Sneak Peak Preview of SquareWear 2.3

There is an upcoming MakerJam at Mount Holyoke College and I’ve been commissioned to create a new version of SquareWear, numbered 2.3. Following the suggestions I’ve received in the past, I made the first prototype of SquareWear 2.3:


Below I list the main changes / improvements:

  • Added Hardware USB-serial Chip (CH340G) : this pretty much follows the same recent change on OpenSprinkler 2.2u. CH340G is a very inexpensive, easy-to-use USB-serial converter. It’s a low-cost replacement of the popular FTDI chip. With a hardware USB-serial chip, SquareWear can now use the same optiboot bootloader as standard Arduinos use. Also, cloud-based Arduino platform, like CodeBender would also work well with SquareWear. Even better, CH340G is supported out of box on Windows 7 and 8, so no more messing with installing USBasp driver, ever!
  • Added Breadboard Pins (dual-purpose): people asked about the possibility of adding breadboard pins, so in this version there are 13 pins on the right edge with standard 0.1″ spacing. These pins are also neatly laid out to serve a second purpose: they match some of the common I2C sensors (particularly MPU6050 6-axis accelerometer) and bluetooth transceiver. This way you can easily plug in sensors and bluetooth transceiver as optional add-ons! The picture on the right above shows how the board looks like with an MPU6050 and bluetooth transceiver plugged in. With this setup, you can easily make a project that involves motion sensor, and even transmit the signal wirelessly to a nearby computer!
  • Upgraded the 3.3V LDO to a bigger chip (SOT-89 packaging) that can provide higher current.
  • Added AT24C128 (16KB) EEPROM: this follows SquareWear Mini, where the added EEPROM can be useful for storing logging data and animation frames.
  • Removed Build-in Rechargeable Coin Cell: I was quite reluctant to make this change, because the built-in rechargeable coin has been one of the main selling points of the original SquareWear. But to make space for the added USB-serial chip, and also to add the breadboard pins, the built-in battery has to go. On the plus side, this makes the design focus on using external LiPo battery, which has higher capacity and the charging current is also suitable increased.

I will look forward to the MakerJam to receive some feedback / comments on the new design.

SquareWear 3D Printed Strap-on Case, April Fool’s Prank, and Temperature Display Demo

The past week has seen some nice community contributions to SquareWear 2.0. The first is a 3D printed strap-on case designed by Paul Modiano:

Very nice and makes SquareWear truly wearable ๐Ÿ™‚ The add-on module in the picture is an ADXL335 accelerometer which takes analog pins A4, A2 and A3. The 3D files can be downloaded from Thingiverse. Thanks Paul for designing this case!

Next is an April fool’s day prank created by Steve Edwards. I don’t have a picture of it, but here is Steve’s description from the comments section:

Great platform for April Fools.

I wrote a sketch that โ€˜delaysโ€™ for 3 hours (to give you a chance to hide the Square and for the victim to fall asleep) and then runs 2 tasks:

1) Every x seconds, beep y tones, of z frequency where x, y, and z are random()ized.

2) Every hour blast out 30 random frequency tones to make sure the victim is awake.

Also, before each tone is played, I check to see if the light sensor is less than 2 so if the victim turns on the lights to look for it, it stops โ€˜beeping.โ€™

I hid 3 in my sonโ€™s room. He didnโ€™t think it was so funny ๐Ÿ™‚

Sounds like a fun gadget to annoy someone ๐Ÿ™‚

I also got an email from Pete Metcalfe who wrote a temperature display demo using SquareWear 2 and the chainable LED matrix. He made a compact display by creating a new, 3×5 pixel array of numbers. The source code is posted below.


I am so glad to see SquareWear 2.0 being gradually picked up by the community, and the interesting applications created and shared by users. More to come later!

// Pete's temperature display demo
void loop(){
float temp = (float)analogRead(PINTEMP);
temp = (temp * 3.3 / 1024 - 0.5) / 0.01; // MCP9700.MCP9700A
// define a 3x5 pixel array
int nums[10][13] = {
{ 0, 1, 2, 7, 9,14,16,21,23,28,29,30,30}, //0
{ 1, 8, 9,15,22,28,29,30,30,30,30,30,30}, //1
{ 0, 1, 2, 7,14,15,16,23,28,29,30,30,30}, //2
{ 0, 1, 2, 7,14,15,16,21,28,29,30,30,30}, //3
{ 0, 2, 7, 9,14,15,16,21,28,28,28,28,28}, //4
{ 0, 1, 2, 9,14,15,16,21,28,29,30,30,30}, //5
{ 2, 9,14,15,16,21,23,28,29,30,30,30,30}, //6
{ 0, 1, 2, 7,14,21,28,28,28,28,28,28,28}, //7
{ 0, 1, 2, 7, 9,14,15,16,21,23,28,29,30}, //8
{ 0, 1, 2, 7, 9,14,15,16,21,28,28,28,28} //9
int dig10 = int(temp/10);
int dig1 = temp - (dig10*10);
for(int i = 0; i < 13 ; i++){ strip.setPixelColor((nums[dig10][i]+4),0,0,255); } for(int i = 0; i < 13 ; i++){ strip.setPixelColor((nums[dig1][i]),0,0,255); } strip.show(); delay(2000); } void clearStrip(){ for(int i = 0; i < strip.numPixels(); i++){ strip.setPixelColor(i,0,0,0); } strip.show(); }

Introducing SquareWear Mini, with All-New Chainable Color LED Matrix, and an Interactive Animation Design Tool

Liked how SquareWear 2.0 has so many built-in components and yet so compact in size? Introducing SquareWear Mini — the little sister of SquareWear that has the same capabilities (and more!) but is 25% smaler in size!


SquareWear Mini

Available for purchase at Rayshobby Shop.

So what is SquareWear Mini? Similar to SquareWear 2.0, the SquareWear Mini is essentially an Arduino running at 3.3V and 12MHz. It is based on the ATmega328 microcontroller, and it has a load of build-in components, including USB port, power switch, pushbutton, buzzer, temperature sensor, light sensor, MOSFETs, lithium battery jack, and lithium battery charger. The pins have enlarged sizes for sewing with conductive threads, for soldering sew-on snaps, and they are great for touch sensing too.

How did I shrink it to be smaller than the original SquareWear? Well, by removing the on-board rechargable coin battery and color LED, and routing some pins to the side. With the space saved, I was even able to add a 16KB I2C EEPROM for storing extra data. Shortly you will see how this is useful. These changes were made because SquareWear designed specially to be attached to a chainable color LED matrix. This will enable a whole new set of exciting projects, as you can see from the video above.


Color LED Matrix

So let me briefly explain the LED matrix. Each matrix contains 35 LEDs arranged on a 5×7 grid with 8mm spacing. It uses the WS2812B color LEDs. These are great because the LED has a built-in chip that allows you to daisey chain them in bulk and still be able to individually set the color of any LED with only one microcontorller pin. Adafruit gave them a name calle the Neopixels. No matter how many LEDs you have, you only need 3 pins to get them to work, namely the VCC, GND, and DATA_IN pins.

These pins are mapped out at the back of the LED matrix. The locations of these pins exactly match the VCC, GND, and digital D10 pins on SquareWear Mini, so you can easily attach SquareWear Mini with the LED matrix by either soldering some sew-on snaps, or directly soldering the two boards together.


The resolution 5×7 is not a whole lot, but it is sufficient to display ASCII characters and a lot of cute icons:


The LED matrix is designed to be chainable too. Each board has DATAIND pins on one side, and DATAOUT on the other side. To extend the number of boards in the X direction, just place two matrices side by side and solder across the 6 pins on the boundary. The solder will get the two boards firmly attached to each other. Chain several boards together to make a large display panel, and it’s great for showing text and messages in any color you want. For example, you can use it as a name tag, or a thermometer (remember, SquareWear Mini has a built-in temperature sensor!)


You can also extend the panel in the Y direction. To do so, use three wires to connect the VCC, GND, and DATA_OUT pins of the previous row to the VCC, GND, DATA_IN pins of the next row. Also solder across the pins on the vertical direction to firmly attach the two rows of boards together. There you go, a bigger panel to display more detailed graphics!


Software Demos

We’ve re-worked the SquareWear software library to include LED matrix demos. These demos work on both the original SquareWear 2.0 and SquareWear Mini. Check the video above for selected examples. The demos are included in the pre-configured software package, and are also available for downloaded individually at the SquareWear Github repository.

What I want to highlight here is the Flipbook Animation demo. It’s a great demo that allows you to interactively design pixel patterns and even an animation. SquareWear Mini can store the frame data into the I2C EEPROM and play it back later. Even better, it comes with sounds too! So how does this work? First, you upload the Flipbook Arduino code to SquareWear. Then, run the Flipbook host software. The host software is written in Processing and is cross-platform. It uses the HID Serial interface to communicate with SquareWear. In the host software you can click on pixels and assign them color values. These values are immediately transferred to SquareWear so you can preview the frame in real-time. For each frame you can specify the frame time and optionally a music note to play. You can create multiple frames, navigate through each frame, make modifications, save the animation to a disk file etc. At last, when you are satisfied with it, click on ‘Transfer to Device’ and the data will be stored into EEPROM. Next time you turn on SquareWear, just click the pushbutton and it will play back the stored animation. Isn’t that cool? With this tool, you never have to think about converting pixel patterns to programming code any more. Let your creativity and imagination take over!


Hope you like SquareWear Mini, and let us know your cool project ideas!

SquareWear 2.0 used at Mount Holyoke College’s iDesign Studio Class

This past week has been a hectic week. Since SquareWear 2.0 got posted on Hack A Day, things have gone quite wild: we’ve got hundreds of orders, and the SquareWear YouTube video accumulated 80,000 views in just two days. By the end of last week, it has exceeded 100,000 views and has officially become the most popular video at the my YouTube channel.

Among the many emails I received, one common question is what can one use SquareWear for other than the examples demonstrated in the video. Well, at heart SquareWear 2.0 is really just a small Arduino with lots of built-in components (notably built-in rechargeable battery and USB port). The large pin pads make it suitable for wearable electronics projects, and the small size makes it suitable for general-purpose microcontroller projects. For example, I’ve used SquareWear to build a reflow oven controller, a OpenSprinkler Pi tester, a USB-based remote for RF power sockets. It’s really versatile.

If you are looking to make some artistic projects, you will be glad to hear this: SquareWear 2.0 was used at the Mount Holyoke College for their iDesign Studio Class. This class was offered by my friend Audrey Lee last semester, and they’ve just concluded the class last month with a fantastic final presentation. I am going to highlight some of the best projects below. For additional information, check the link above — each project has a website with detailed write-up. I am sure they will inspire you to come up with your own fantastic project idea.

One of my favorite is the Accelexpression project by Madeline Ketley. She combined a SquareWear with a gyro sensor and NeoPixel LED strip to make a smart skirt for dancers. The LED strip displays different colors depending on the standing position of the dancer. It is not only artistic and visually beautiful, but it’s a very useful tool for training dancers: from the color of the LEDs you can easily tell if the dancer is standing straight, or if two dancers are synchronized in their moves. It’s a brilliant idea and I was completely impressed. Here are some rather blurry pictures. I wish I had taken high-quality pictures or even better a video!


Another favorite of mine is Meaghan Sullivan’s Reading Hardwired. Meaghan made a hand-drawn picture book featuring a timid and cute cameleon. She then combined a SquareWear, copper sheets, some neopixels, and photo-resistors to make the picture book change colors as you turn the pages. It’s so artistic, vivid, and truly brilliant!

Neopixels seems to be a big hit among students. Alexis Andrus used strips of Neopixels to make a beatuful iDesign Jacket; Ione Brogna also used Neopixel strips to make iTech Accessories, such as these stylish shoulder straps belts. Ione also added a sound sensor to SquareWear and made her iTech accessories respond to music and beats.


Next up, with Julia Rycyna’s La Coeur du Dragon project, we enter the fantasy land of dragons. She first made a plush dragon with flapping wings using a SquareWear and some muscle wires. Thanks to the build-in MOSFETs on SquareWear, no external muscle wire drivers were needed. Then she added a ultrasonic distance sensor and a LED heart to the dragon, so that the heart blinks faster as you approach the dragon. Quick, hold it tight, how can you bear with putting such a lovely dragon down!


Safae Lahgazi Alaoui presented an amazingly artistic project called the Interactive Mirror. The mirror is decorated with LEDs and responds to sound, touch, and motion. Check the images below and appreciate the complexity of the mirror.


Eva Snyder’s musicTouch project is a great educational tool to teach kids about music and tones. It uses conductive ink and touch sensing to let you play music interactively. If you are interested, be sure to check out my previous blog post about how to use SquareWear to create a touch-based digital piano without any additional hardware.


Thinking of some other creative uses of SquareWear? Saadia Gabriel made a solar charging jacket called The Turtle? It makes use of SquareWear to charge a lithium battery, which is then bumped to 5V using a boost converter for charging cell phones. Athena Donta and MJ Lee created the Bad Weather Wear project, which combines a SquareWear, LED matrix, and conductivity sensor onto a pair of mittens. When it rains or snows, the LED matrix displays smileys and different patterns to keep you happy in bad weather. Isn’t that sweet?


If you are inspired by these projects, consider getting a SquareWear 2.0 from our shop. It’s a great little gadget to help explore the creative and artistic side of you!

SquareWear 2.0 Touch Sensing and Digital Piano Demo

Looking for new projects to do with SquareWear 2.0? Here is an idea: combine SquareWear 2.0 with touch sensing to make a digital piano! It works as a standalone project and no additional hardware is required. Take a look at the video first:

How does this work? First, SquareWear 2.0 has a built-in buzzer, so it can already make sound. Next, touch sensing is detected in software. It basically exploits the principle of capacitive sensing: every time you touch an Arduino pin, it slightly alters the capacitance of the pin. This change of capacitance can be detected using a variety of methods. The simplest is to set the pin to digital input mode, and turn on the internal pull-up resistor. This will start charging the capacitor. By detecting the time it takes to charge the capacitor, you can infer the capacitance, and in turn tell if a finger touch has occurred on the pin. That’s it! Because SquareWear maps out available pins to large pin pads, this makes it particularly well-suited for touch sensing.

So I wrote a quick demo as a proof-of-concept. First, I found a function that implements the capacitive sensing from the Arduino playground website. It basically returns a touching sensing value, which can then be compared to a threshold. You may need to adjust the threshold to increase or decrease the sensitivity. The demo scans through all 12 pins available on the SquareWear 2.0 and plays a tone for 125 milliseconds if a pin touch is detected. As a result, the buzzer makes a chiptune type of sound. The code also uses the on-board pushbutton to switch between three octaves: C3, C4, and C5. The LED will blink when a tone is played.

A few notes and quirks:

  • The code works the best if you plug in a USB cable connected to your computer.
  • You can also moisten your figures to help increase the touch sensitivity.
  • If you unplug the USB cable, it generally helps if you use one hand to hold the battery, or the VCC or GND pin. You may need to cover the ISP pins on the back side to avoid touching them. Holding the battery, VCC or GND helps amplify small capacitive changes.
  • The MOSFET pins (D3, D5, D6) do not seem to work well without the USB cable. To be honest, I was surprised that these pins even worked at all, because the pads are not directly connected to the pins (rather, the connection is through a MOSFET). So if you need, you can modify the source code to disable these pins.

The demo code is available in the SquareWear 2.0 software package on Github. The direct download link is below:

I will keep posting new project ideas in the upcoming weeks. SquareWear 2.0 is available for purchase at the Rayshobby Shop. At a price of $22 and with a load of built-in components, it’s a great little gadget to help you learn Arduino programming, and build wearable as well as general-purpose electronic projects. Hope you like this demo and your support is greatly appreciated!

Introducing SquareWear 2.0 — An Open-Source Wearable Arduino

This is a long delayed post. I am glad I finally finished making a video for it, and it’s time to introduce SquareWear 2.0 — an open-source, wearable Arduino microcontroller board. At heart, SqureWear 2.0 is an Arduino running at 3.3V and 12MHz. It has built-in mini-USB port for uploading programs, charging lithium batteries, and creating a serial communication channel. It comes with a lot of useful built-in components, such as a color LED, a general-purpose push-button, a buzzer (yup, you can make it sing a tune), light sensor, temperature sensor, three MOSFETs (to drive high-current load). Even better, it has a built-in rechargeable lithium coin battery (you heard it right: rechargeable coin battery!), so you can power your project right away without requiring external power supply. Every time you plug in the mini-USB cable, it charges the coin battery automatically. Better still, if you want a beefier battery, you can plug in an external lithium battery through the on-board battery jack. The built-in lithium charger can charge external battery as well. Overall SquareWear 2.0 packs a lot of useful features on a 1.7″ x 1.7″ board. It’s great for wearable electronic projects as well as general-purpose microcontroller projects. Below is a summary of built-in components:

  • ATmega328 running at 3.3V, 12MHz.
  • MCP1700 3.3V / 250mA LOD.
  • MCP73831 lithium charging chip (configured to charge at 35mA).
  • MCP9700 temperature sensor.
  • 10K photo-resistor.
  • Four 2N7002 MOSFETs.
  • 5050 color LED.
  • 8.5mm SMT buzzer.
  • 6mm SMT tactile button.
  • Charging indicator LED.
  • LIR2032 rechargeable lithium coin battery (45mAh capacity).
  • 2.0mm JST connector for external lithium battery.
  • SMT mini-USB port, and power switch.



Last year around this time I released SqureWear 1.1, which is based on Microchip’s 18F14K50 microcontroller. It’s pretty neat, but over time I’ve received quite a few requests to develop a similar board based on the Arduino. This inspired me to work on SquareWear 2.0. Many design choices, including components I selected to put on board, were based on feedback and experience at various wearable electronics workshops I organized.

With SquareWear 2.0, programming is now done through the Arduino software. You can make use of thousands of available Arduino libraries to help build your project. Similar to the standard Arduino, it is based on a ATmega328 microcontroller. However, SquareWear does not have a separate USB-to-serial chip. Instead, it simulates USB functionality all in software, using the V-USB library. It has a USBasp bootloader, and can perform serial communication through USB. It can also simulate a mouse, a keyboard, or other human interface devices (see V-USB example projects). While software-based USB is not that fast, it really helps reduce the cost and size of the board by having one chip to carry out all the tasks. That’s why we can offer SquareWear 2.0, with all the aforementioned components and features, at a very competitive price.

The bootloader is based on Frank Zhao’s USnoobie project. To enter programming mode, press and hole the on-board tactile button, then turn on power. This will allow the microcontroller to bootload as a USBasp programmer, which is supported by Arduino. On Linux and Mac, you don’t need to install any driver; on Windows, you need to install the USBasp driver (come on, Microsoft!), which is included in the SqureWear software package. The board has internal assignments for the following pins:

  • D2/D7: USB D-/D+.
  • D4: tactile button.
  • D8/D12/D13: LED red/green/blue channel.
  • D9: buzzer.
  • A0/A1: light/temperature sensor.

The other pins are all mapped out to sewable pin pads with large holes. You can either stitch conductive threads through the pins, or solder wires directly onto the pins, or solder snaps to make it easy for quickly attaching or detaching the board from fabric.


I should mention that pins D3, D5, D6 are internally connected to n-channel MOSFETs and these pins are suitable for driving high-current load (up to 250mA each pin). This is very useful if you want to switch a large number of parallel LEDs, a motor, a muscle wire, a heat wire etc. You can even combine two or three of them together to drive higher current. If you are familiar with Arduino, you should know that these three pins also support hardware PWM, so you can use them to control the brightness of LEDs, the speed of a motor etc. Technically I call them ‘power sink pins’ because unlike a standard output pin, they can only connect or disconnect a component from ground (sink). So the right way to use them is by connecting the positive wire of your component to Vcc (or external power), and the negative wire to one of the MOSFET pins.

Anyways, I want to keep this post short, so I will leave you to find more details in the video tutorial above, and the user manual in the software package. If you are interested in buying SquareWear 2.0, it’s available for purchase at the Rayshobby Shop. Feel free to leave comments below, or on the forum. Thanks!

RI Mini Maker Faire Pictures

Yesterday we went to the RI Mini Maker Faire in Providence. I came back around midnight last night, feeling quite tired. It was a fun trip, and the first time that I went there as a maker. The faire was co-located with the Foo Fest, so even though its size is nowhere comparable to the Bay Area Maker Faire and New York Maker Faire, there were still a decent number of people. We had a single and fairly small table to showcase everything. As you can see from the pictures below, the table was very crowded, but we managed to lay out everything I wanted to show, and the promotional materials as well ๐Ÿ™‚

As in previous Maker Faires, the most fun and rewarding part of the experience is that I get to talk to a lot of different people, explain to them how electronic gadgets work, get them excited about electronics, answer their questions, and hear their innovation ideas and solutions. I had two students, Kim and Cheni, who kindly offered their help, so I got to spend more time talking to people.



One tip I learned from the Bay Area Maker Faire earlier this year is that everyone is really excited about blinking LEDs. I know, it sounds trivial, but really, everyone loves it. Last time I just accidentally packed a hundred self-flashing and RGB color LEDs, together with coin batteries in my baggage. While setting up the table, an idea popped up in my mind that we can distribute them as free gifts at the faire. They are really cheap, so I don’t mind giving them away. What I didn’t foresee was how popular this was: the one hundred packets were gone almost in no time.

So this time, I am better prepared: I brought a bag of one thousand self-flashing and RGB color LEDs, together with one thousand batteries! We printed instructions so people can learn how to make an LED throwie on their own (basically sandwiching a coin battery in between the two legs of an LED). We distributed these as free gift to people, but told them it’s only free if they make one themselves (instead of taking away our demos ๐Ÿ™‚ ) This was a huge success: I estimated that we gave away at least 250 of these. Many people passing by the table saw this and were eager to give it a try. Kids especially love these. Kim and Cheni were busy cutting tape and helping others learn to build their LED throwies. It’s really rewarding to see something so easy to learn can get people to excited, and it’s also fun to see how people were teaching each other at the table, and bringing their own friends to learn how to build these. Perhaps to some this will motivate them to explore the world of electronics. Then I will feel I have fulfilled my education mission a little bit ๐Ÿ™‚