Arduino Basics: best arduino blog
Showing posts with label best arduino blog. Show all posts
Showing posts with label best arduino blog. Show all posts

14 September 2018

Getting Started with the Keyes ESP-13 WiFi Shield

Description

This tutorial will help you get started with the KEYES ESP-13 WiFi Shield.

The ESP-13 WiFi Shield is compatible with an Arduino UNO and has the same form-factor. Essentially this shield will give your Arduino project WiFi capabilities. While it interfaces nicely with the Arduino, it can operate without it. However, if I were planning on using the shield independantly, then I probably would opt for an ESP module rather than a shield.

I bought my shield from Jaycar (CAT.NO: XC4614), however you can get it much cheaper from other online retailers at about a quarter of the price. The instructions on the Jaycar website are not that good, and at first I thought I had bought myself a useless product. It just didn't seem to work regardless of what I tried. There were some tutorials online that gave me hope, only to find that my shield was not quite the same and therefore I did not get the same results. But after countless hours of trial and error and patching various bits of knowledge together, I finally worked out how to use this shield. Everything has fallen into place. And it is easier that you would think... let me show you how.

13 October 2015

Arduino LED Light Box

Description

Long straight lines of LED luminescence is nice, but sometimes you may want to light up something that has an unusual shape, or is not so linear. This is where the 12mm diffused flat digital RGB LED Pixels can come into play. This cool strand of 25 RGB LED pixels fit nicely into 12mm pre-drilled holes of any material you like.

This tutorial is dedicated to making a LED Light Box. I wanted the box to be equally as interesting during the day as it was at night. If you decide you make your own, feel free to be as creative as you want !! However, if you lack artistic acumen, you may need to source a minion or two.


 

Arduino Libraries and IDE

Before you start to hook up any components, upload the following sketch to the Arduino microcontroller. I am assuming that you already have the Arduino IDE installed on your computer. If not, the IDE can be downloaded from here.

The FastLED library is useful for simplifying the code for programming the RGB LED pixels. The latest "FastLED library" can be downloaded from here. I used FastLED library version 3.0.3 in this project.

If you have a different LED strip or your RGB LED pixels have a different chipset, make sure to change the relevant lines of code to accomodate your hardware. I would suggest you try out a few of the FastLED library examples before using the code below, so that you become more familiar with the library, and will be better equipped to make the necessary changes.

If you have a single strand of 25 RGB LED pixels with the WS8201 chipset, then you will not have to make any modification below.


 

ARDUINO CODE:

Arduino Code Description

The code above will generate a randomised raindrop pattern on the Arduino LED Light box, however I have written code for a few more LED animations. These animations were written specifically for this light-box setup. In other words, once you have hooked everything up, you will be able to upload these other LED animations to the Arduino board without any further modification to the hardware/wiring, and yet experience a totally different light effect. You can find the code for the other animation effects by clicking on the links below:

  1. Breathing effect
  2. Ripple effect
  3. Clock effect
  4. Rotation effect
  5. Sweep effect
  6. Spiral effect
  7. Lightning effect
  8. Paparazzi in the Rain effect

Hooking it up:

Power requirements

Each LED pixel can draw up to 60 milliamps at maximum brightness (white). ie. 20 mA for each colour (red, green and blue). Therefore you should not try to power the LED strand directly from the Arduino, because the strand will draw too much current and damage the microcontroller(and possibly your USB port too). The LED strand will therefore need to be powered by a separate power supply. The power supply must supply the correct voltage (5V DC) and must also be able to supply sufficient current (1.5A or greater per strand of 25 LEDs).

Excessive voltage will damage or destroy your LED pixel strand. The LEDs will only draw as much current as they need, however your power supply must provide at least 1.5A or greater for each strand. If you chain two strands together, you will need a 5V 3A power supply.

RGB LED pixel strand connection

There are 25 LED pixels per strand. Four of the wires at each end of the strand are terminated with a JST connector. The red wire is for power (VCC), blue wire for ground (GND), yellow wire is for Data, and green wire for Clock. A spare red wire (VCC) and a spare blue wire (GND) are attached to the ends of each strand for convenience, however, I did not use either. Please double check the colour of your wires... they may be different.

If you want to attach the LED strand to a breadboard, you can cut the JST connector off and use the LED pixel strand wires. Alternatively, if you would prefer to preserve the JST connector, you can simply insert jumper wires (or some male header pins) into the JST connector, and then plug them into the breadboard as required.

Each LED pixel is individually controllable using two pins on your Arduino. The strand is directional. i.e. There is an INPUT side and an OUTPUT side. The strand should be connected such that wires from the microcontroller are attached to the INPUT side of the first LED pixel. The arrows on each LED show the direction of data flow from INPUT to OUTPUT. The arrow on the first LED pixel should be pointing towards the second LED pixel, NOT towards the breadboard.

Other considerations

As a precaution, you should use a large capacitor across the + and - terminals of the power supply to prevent the initial onrush of current from damaging the RGB LED pixels. I used a 4700uF 16V Electrolytic capacitor for this purpose. According to Adafruit, a 1000uF 6.3V capacitor (or higher) will also do the trick. You may also want to consider a 330 ohm resistor between the Arduino Digital pin and the strand's DATA pin.

If you want to power the Arduino using the regulated 5V external power supply. Disconnect the USB cable from the Arduino, and then connect the positive terminal of the power supply to the 5V pin on the Arduino. Be warned however, that excess voltage at this pin could damage your Arduino, because the 5V regulator will be bypassed.
 
Providing the USB cable is NOT connected to the Arduino, it should now be safe to plug the power supply into the wall. This setup will allow you to power the RGB LED pixel strand and the Arduino using the same power supply.
 
WARNING: Never change any connections while the circuit is powered.

For more information about these RGB LED pixel strands, you may want to visit the Adafruit site. Adafruit was the source for most of these RGB LED pixel Strand precautions.


Fritzing diagram

The following diagram demonstrates how to connect the RGB LED pixel Strand to the Arduino and to the External 5V power supply.


This diagram was created using Fritzing


Connection Instructions

These instructions will help to guide you through the process of connecting your RGB LED pixel strand to the Arduino, and to the external power supply. The instructions assume that you will be powering the Arduino via a USB cable.



LightBox assembly

You will need to drill a 12mm hole into the craft timber box for each LED on the strand. It is worth taking the time to make accurate measurements before drilling the holes.
 
I made 12 holes for the outside circle pattern (12cm diameter), 6 holes for the inside circle pattern (8cm diameter), and a hole in the centre. I also made two holes at the front of the box, two on the left side, and two on the right side. I made one last hole at the back of the box for the 2.1mm DC power line socket.
 
Therefore you should have a total of 26 holes in the box. 25 of the holes are for the RGB LED pixel LEDs and one for the external power supply socket.

The lid of the box is about 19.5cm x 14.5cm long, which makes for a very tight squeeze. Probably too tight, because you have to account for the inner dimensions of the box. The inside of the box is used to house the Arduino, breadboard, the chipset side of the LEDs and cables/components. The inner dimensions of the box are 18cm x 13cm. Therefore, the housing for the LED chipset PCB (1.8cm x 2.5cm) prevented the box from closing. I used a Dremel to carve out the space required to close the lid.

Each LED is approximately 8cm apart on the strand, however, if you are really keen, you could cut the wires and extend them to any distance you require. But keep in mind that each LED is mounted on a small PCB (with a WS2801 chipset).You will therefore need to leave a minimum of 2cm between each 12mm hole to accomodate the size of the PCB+LED. If you plan carefully, you can probably squeeze a couple of LEDs within a distance of 1cm... but I would recommend that you give yourself a bit more room, because the PCBs are not square, and there is a good chance that you will have to start all over again.

In hindsight, I could have made the circle patterns a bit smaller, however I don't know if I could have packed these LEDs any closer. The diameter of the inner circle pattern must be at least 2cm smaller than the outer circle pattern. So I think "a bigger box" would have been the best option.

Once all of the holes have been drilled, paint and decorate the box to suit your style.

When the paint is dry, insert the LEDs into the drilled holes in number order.
You can see the end result below.



Project Pictures

These pictures show the Light box after it has been drilled and painted. The LEDs have been inserted into their respective holes, and all wires + Arduino + breadboard are hidden within the box.





Concluding comments

Once you start writing LED animations for the RGB LED pixel Lightbox, it is very hard to stop. The colour combinations



If you like this page, please do me a favour and show your appreciation :

 
Visit my ArduinoBasics Google + page.
Follow me on Twitter by looking for ScottC @ArduinoBasics.
I can also be found on Pinterest and Instagram.
Have a look at my videos on my YouTube channel.



However, if you do not have a google profile...
Feel free to share this page with your friends in any way you see fit.

4 August 2015

MT8870 DTMF - Dual Tone Multi Frequency Decoder

Project Description

We will be using an MT8870 DTMF module with an Arduino UNO to control a small servo motor in this project. The DTMF module gives the Arduino super-powers and allows you to control the Servo motor in so many ways. For example, this tutorial will show you how to control the servo motor using:
  • a YouTube Video
  • a voice recorder
  • A web application (Online tone generator)
  • A smart phone app (DTMF Pad)
  • A touch-tone phone to cell-phone call
All of these control methods will take advantage of the same exact Arduino code/sketch. But how???
The MT8870 DTMF decoder is quite a neat little module that allows you incorporate DTMF technology into your arduino projects. DTMF stands for Dual-Tone Multi-Frequency. DTMF tones are commonly associated with touch-tone phones and other telecommunication systems. When you press the number "1" on a touch-tone phone, two sine waves with frequencies: 697Hz and 1209Hz are combined to produce a unique DTMF signal which can be transmitted through the phone line. The MT8870 DTMF module can take this signal as an input, and decode it to produce a binary output.
 
 

 
The DTMF module does not care how you produce the DTMF tone. However, if it receives this tone, it will decode it. We can take advantage of this feature to supply the module with tones from different sources. The module has a 3.5mm port for line input. Providing you can connect your DTMF source to this line input in some way, it should work. I must warn you, however that this is a line input and NOT a microphone input. If you wanted to use a microphone, you will need to boost or amplify the signal before sending it to the DTMF module.
 
You will need the following parts for this project
 

Parts Required:

Software/Apps Required

Arduino Sketch


Upload the following sketch to the Arduino.
 

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/* ================================================================================================================================================== Project: MT8870 DTMF Servo sketch Author: Scott C Created: 4th August 2015 Arduino IDE: 1.6.4 Website: http://arduinobasics.blogspot.com/p/arduino-basics-projects-page.html Description: This project will allow you to control a Servo motor using an Arduino UNO and a MT8870 DTMF Module. The DTMF signal is received through the 3.5mm port of the DTMF module and is decoded. We will use the decoded output to control the position of the Servo. A SG-5010 Servo motor was used in this project. ===================================================================================================================================================== */ //This sketch uses the Servo library that comes with the Arduino IDE #include <Servo.h> //Global variables----------------------------------------------------------------------------------------- Servo SG5010; // The SG5010 variable provides Servo functionality int servoPosition = 0; // The servoPosition variable will be used to set the position of the servo byte DTMFread; // The DTMFread variable will be used to interpret the output of the DTMF module. const int STQ = 3; // Attach DTMF Module STQ Pin to Arduino Digital Pin 3 const int Q4 = 4; // Attach DTMF Module Q4 Pin to Arduino Digital Pin 4 const int Q3 = 5; // Attach DTMF Module Q3 Pin to Arduino Digital Pin 5 const int Q2 = 6; // Attach DTMF Module Q2 Pin to Arduino Digital Pin 6 const int Q1 = 7; // Attach DTMF Module Q1 Pin to Arduino Digital Pin 7 /*========================================================================================================= setup() : will setup the Servo, and prepare the Arduino to receive the MT8700 DTMF module's output. ========================================================================================================== */ void setup() { SG5010.attach(9); // The Servo signal cable will be attached to Arduino Digital Pin 9 SG5010.write(servoPosition); // Set the servo position to zero. //Setup the INPUT pins on the Arduino pinMode(STQ, INPUT); pinMode(Q4, INPUT); pinMode(Q3, INPUT); pinMode(Q2, INPUT); pinMode(Q1, INPUT); } /*========================================================================================================= loop() : Arduino will interpret the DTMF module output and position the Servo accordingly ========================================================================================================== */ void loop() { if(digitalRead(STQ)==HIGH){ //When a DTMF tone is detected, STQ will read HIGH for the duration of the tone. DTMFread=0; if(digitalRead(Q1)==HIGH){ //If Q1 reads HIGH, then add 1 to the DTMFread variable DTMFread=DTMFread+1; } if(digitalRead(Q2)==HIGH){ //If Q2 reads HIGH, then add 2 to the DTMFread variable DTMFread=DTMFread+2; } if(digitalRead(Q3)==HIGH){ //If Q3 reads HIGH, then add 4 to the DTMFread variable DTMFread=DTMFread+4; } if(digitalRead(Q4)==HIGH){ //If Q4 reads HIGH, then add 8 to the DTMFread variable DTMFread=DTMFread+8; } servoPosition = DTMFread * 8.5; //Set the servoPosition varaible to the combined total of all the Q1 to Q4 readings. Multiply by 8.5 to amplify the servo rotation. } SG5010.write(servoPosition); //Set the servo's position according to the "servoPosition" variable. }


 
 
 

Fritzing Sketch


Connect the Arduino to the MT8870 DTMF module, and to a Servo.
Use the following Fritzing sketch as a guide.
 
(Click the image above to enlarge it)



Discussion


You will need to connect a cable from the DTMF module's 3.5mm port to that of your smart phone, computer, voice recorder or any other DTMF source of your choice.
 

 

When you power up your Arduino, the Servo motor should turn all the way to the left to it's zero position. Once the DTMF module receives a DTMF signal, it will identify the relevant frequecies as described in the table at the beginning of this tutorial, and produce a binary like output. You will notice the DTMF module's onboard LEDs light up when a tone is detected. Onboard LED (D5) will turn on for the length of the DTMF tone it just received, and turn off when the tone has stopped. On the other hand, the onboard LEDs (D1 to D4) will light up depending on the tone received, and will remain lit until the module receives another tone. The onboard LEDs are a visual representation of the voltages applied to the DTMF module's pins (Q1 to Q4, and STQ). Q1 matches D1, Q2 matches D2 etc etc. and STQ matches D5.
 
You will notice that there are two STQ pins on the DTMF module. The STQ pin that is closest to Q4 will only go high when a DTMF tone is detected, and will remain high for the duration of the tone. The other STQ pin is the exact opposite. It will switch LOW when a tone is received and remain LOW for the duration of the tone. When there is no tone, this STQ pin will remain HIGH. The table below provides a summary of the DTMF module outputs, with a blue box representing a voltage applied to that pin (HIGH), whereas a black box indicates no voltage applied (LOW).


 
In order to follow this project, you need a source of DTMF tones. You can produce DTMF tones using a touch-tone phone, or through the use of a DTMF Pad app. If you are feeling creative, you can create a DTMF song/tune like the one I posted on YouTube. You can see the video below:
 

 
As you can see from the video, I also recorded the DTMF tune onto a voice recorder, and was able to control the servo that way. If you are not feeling creative, you can visit this website to create DTMF tones from your browser.

Concluding comments


This project was very fun, and shows some novel ways to control your Arduino. After completing the project, I realised that I could use this module to alert me when new emails or messages arrive on my phone or computer. If you have the ability to change the email or message notification sound to a DTMF tone, you should be able to get the module and Arduino to respond accordingly. Oh well, maybe I'll save that project for another day.
 
If this project helped you in anyway or if you use my code within your project, please let me know in the comments below. I would be interested to see what you did.


If you like this page, please do me a favour and show your appreciation :

 
Visit my ArduinoBasics Google + page.
Follow me on Twitter by looking for ScottC @ArduinoBasics.
I can also be found on Pinterest and Instagram.
Have a look at my videos on my YouTube channel.


 
 
             

 



However, if you do not have a google profile...
Feel free to share this page with your friends in any way you see fit.

18 July 2015

NeoPixel Heart Beat Display


Project Description


In this project, your heart will control a mesmerising LED sequence on a 5 metre Neopixel LED strip with a ws2812B chipset. Every heart beat will trigger a LED animation that will keep you captivated and attached to your Arduino for ages. The good thing about this project is that it is relatively easy to set up, and requires no soldering. The hardest part is downloading and installing the FastLED library into the Arduino IDE, but that in itself is not too difficult. The inspiration and idea behind this project came from Ali Murtaza, who wanted to know how to get an LED strip to pulse to his heart beat.
 
Have a look at the video below to see this project in action.
 
 
 

The Video


 


 
 

Parts Required:


 

Power Requirements

Before you start any LED strip project, the first thing you will need to think about is POWER. According to the Adafruit website, each individual NeoPixel LED can draw up to 60 milliamps at maximum brightness - white. Therefore the amount of current required for the entire strip will be way more than your Arduino can handle. If you try to power this LED strip directly from your Arduino, you run the risk of damaging not only your Arduino, but your USB port as well. The Arduino will be used to control the LED strip, but the LED strip will need to be powered by a separate power supply. The power supply you choose to use is important. It must provide the correct voltage, and must able to supply sufficient current.
 

Operating Voltage (5V)

The operating voltage of the NeoPixel strip is 5 volts DC. Excessive voltage will damage/destroy your NeoPixels.

Current requirements (9.0 Amps)

OpenLab recommend the use of a 5V 10A power supply. Having more Amps is OK, providing the output voltage is 5V DC. The LEDs will only draw as much current as they need. To calculate the amount of current this 5m strip can draw with all LEDs turned on at full brightness - white:

30 NeoPixel LEDs x 60mA x 5m = 9000mA = 9.0 Amps for a 5 metre strip.

Therefore a 5V 10A power supply would be able to handle the maximum current (9.0 Amps) demanded by a 5m NeoPixel strip containing a total of 150 LEDs.
 
 


Arduino Libraries and IDE


Before you start to hook up any components, upload the following sketch to the Arduino microcontroller. I am assuming that you already have the Arduino IDE installed on your computer. If not, the IDE can be downloaded from here.
 
The FastLED library is useful for simplifying the code for programming the NeoPixels. The latest "FastLED library" can be downloaded from here. I used FastLED library version 3.0.3 in this project.
 
If you have a different LED strip or your NeoPixels have a different chipset, make sure to change the relevant lines of code to accomodate your hardware. I would suggest you try out a few of the FastLED library examples before using the code below, so that you become more familiar with the library, and will be better equipped to make the necessary changes. If you have a 5 metre length of the NeoPixel 30 LED/m strip with the ws2812B chipset, then you will not have to make any modification below.
 

ARDUINO CODE:


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/* ================================================================================================ Project: NeoPixel Heart Beat Display Neopixel chipset: ws2812B (30 LED/m strip) Author: Scott C Created: 8th July 2015 Arduino IDE: 1.6.4 Website: http://arduinobasics.blogspot.com/p/arduino-basics-projects-page.html Description: This sketch will display a heart beat on a 5m Neopixel LED strip. Requires a Grove Ear-clip heart rate sensor and a Neopixel strip. This project makes use of the FastLED library: http://fastled.io/ You may need to modify the code below to accomodate your specific LED strip. See the FastLED library site for more details. ================================================================================================== */ //This project needs the FastLED library - link in the description. #include "FastLED.h" //The total number of LEDs being used is 150 #define NUM_LEDS 150 // The data pin for the NeoPixel strip is connected to digital Pin 6 on the Arduino #define DATA_PIN 6 //Attach the Grove Ear-clip heart rate sensor to digital pin 2 on the Arduino. #define EAR_CLIP 2 //Initialise the LED array CRGB leds[NUM_LEDS]; //Initialise the global variables used to control the LED animation int ledNum = 0; //Keep track of the LEDs boolean beated = false; //Used to identify when the heart has beated int randomR = 0; //randomR used to randomise the fade-out of the LEDs //================================================================================================ // setup() : Is used to initialise the LED strip //================================================================================================ void setup() { FastLED.addLeds<NEOPIXEL,DATA_PIN>(leds, NUM_LEDS); //Set digital pin 2 (Ear-clip heart rate sensor) as an INPUT pinMode(EAR_CLIP, INPUT); } //================================================================================================ // loop() : Take readings from the Ear-clip sensor, and display the animation on the LED strip //================================================================================================ void loop() { //If the Ear-clip sensor moves from LOW to HIGH, call the beatTriggered method if(digitalRead(EAR_CLIP)>0){ //beatTriggered() is only called if the 'beated' variable is false. //This prevents multiple triggers from the same beat. if(!beated){ beatTriggered(); } } else { beated = false; //Change the 'beated' variable to false when the Ear-clip heart rate sensor is reading LOW. } //Fade the LEDs by 1 unit/cycle, when the heart is at 'rest' (i.e. between beats) fadeLEDs(5); } //================================================================================================ // beatTriggered() : This is the LED animation sequence when the heart beats //================================================================================================ void beatTriggered(){ //Ignite 30 LEDs with a red value between 0 to 255 for(int i = 0; i<30; i++){ //The red channel is randomised to a value between 0 to 255 leds[ledNum].r=random8(); FastLED.show(); //Call the fadeLEDs method after every 3rd LED is lit. if(ledNum%3==0){ fadeLEDs(5); } //Move to the next LED ledNum++; //Make sure to move back to the beginning if the animation falls off the end of the strip if(ledNum>(NUM_LEDS-1)){ ledNum=0; } } //Ignite 20 LEDS with a blue value between 0 to 120 for(int i = 0; i<20; i++){ //The blue channel is randomised to a value between 0 to 120 leds[ledNum].b=random8(120); FastLED.show(); //Call the fadeLEDs method after every 3rd LED is lit. if(ledNum%3==0){ fadeLEDs(5); } //Move to the next LED ledNum++; //Make sure to move back to the beginning if the animation falls off the end of the strip if(ledNum>(NUM_LEDS-1)){ ledNum=0; } } //Change the 'beated' variable to true, until the Ear-Clip sensor reads LOW. beated=true; } //================================================================================================ // fadeLEDs() : The fading effect of the LEDs when the Heart is resting (Ear-clip reads LOW) //================================================================================================ void fadeLEDs(int fadeVal){ for (int i = 0; i<NUM_LEDS; i++){ //Fade every LED by the fadeVal amount leds[i].fadeToBlackBy( fadeVal ); //Randomly re-fuel some of the LEDs that are currently lit (1% chance per cycle) //This enhances the twinkling effect. if(leds[i].r>10){ randomR = random8(100); if(randomR<1){ //Set the red channel to a value of 80 leds[i].r=80; //Increase the green channel to 20 - to add to the effect leds[i].g=20; } } } FastLED.show(); }


 

NeoPixel Strip connection

The NeoPixel strip is rolled up when you first get it. You will notice that there are wires on both sides of the strip. This allows you to chain LED strips together to make longer strips. The more LEDs you have, the more current you will need. Connect your Arduino and power supply to the left side of the strip, with the arrows pointing to the right. (i.e. the side with the "female" jst connector).
 



NeoPixel Strip Wires

There are 5 wires that come pre-attached to either side of the LED strip.
 

 
You don't have to use ALL FIVE wires, however you will need at least one of each colour: red, white & green.
 

 

Fritzing sketch

The following diagram will show you how to wire everything together
 
(click to enlarge)

Arduino Power considerations

Please note that the Arduino is powered by a USB cable.
If you plan to power the Arduino from your power supply, you will need to disconnect the USB cable from the Arduino FIRST, then connect a wire from the 5V line on the Power supply to the 5V pin on the Arduino. Do NOT connect the USB cable to the Arduino while the 5V wire is connected to the Arduino.
 

 

Large Capacitor

Adafruit also recommend the use of a large capacitor across the + and - terminals of the LED strip to "prevent the initial onrush of current from damaging the pixels". Adafruit recommends a capacitor that is 1000uF, 6.3V or higher. I used a 4700uF 16V Electrolytic Capacitor.
 

 

Resistor on Data Pin

Another recommendation from Adafruit is to place a "300 to 500 Ohm resistor" between the Arduino's data pin and the data input on the first NeoPixel to prevent voltage spikes that can damage the first pixel. I used a 330 Ohm resistor.
 

 

Grove Ear-clip heart rate sensor connection

The Grove Base shield makes it easy to connect Grove modules to the Arduino. If you have a Grove Base shield, you will need to connect the Ear-clip heart rate sensor to Digital pin 2 as per the diagram below.
 

 

Completed construction

Once you have everything connected, you can plug the USB cable into the Arduino, and turn on the LED power supply. Attach the ear-clip to your ear (or to your finger) and allow a few seconds to allow the sensor to register your pulse. The LED strip will light up with every heart beat with an animation that moves from one end of the strip to the other in just three heart beats. When the ear-clip is not connected to your ear or finger, the LEDs should remain off. However, the ear clip may "trigger" a heart beat when opening or closing the clip.
 
Here is a picture of all the components (fully assembled).
 


Concluding comments


This very affordable LED strip allows you to create amazing animations over a greater distance. I thought that having less LEDs per metre would make the animations look "jittery", but I was wrong, they look amazing. One of the good things about this strip is the amount of space between each Neopixel, allowing you to easily cut and join the strip to the size and shape you need.
 
This LED strip is compatible with the FastLED library, which makes for easy LED animation programming. While I used this LED strip to display my heart beat, you could just as easily use it to display the output of any other sensor attached to the Arduino.
 



If you like this page, please do me a favour and show your appreciation :

 
Visit my ArduinoBasics Google + page.
Follow me on Twitter by looking for ScottC @ArduinoBasics.
I can also be found on Pinterest and Instagram.
Have a look at my videos on my YouTube channel.


 
 
             

 
This project would not have been possible without OpenLab's collaborative effort.
Please visit their site for more cool projects.



However, if you do not have a google profile...
Feel free to share this page with your friends in any way you see fit.

22 June 2015

Send HEX values to Arduino

FIVE MINUTE TUTORIAL

Project Description: Sending Hex values to an Arduino UNO


This simple tutorial will show you how to send Hexadecimal values from a computer to an Arduino Uno. The "Processing" programming language will be used to send the HEX values from the computer when a mouse button is pressed. The Arduino will use these values to adjust the brightness of an LED.



 

Learning Objectives


  • To Send Hexadecimal (Hex) values from a computer to the Arduino
  • Trigger an action based on the press of a mouse button
  • Learn to create a simple Computer to Arduino interface
  • Use Arduino's PWM capabilities to adjust brightness of an LED
  • Learn to use Arduino's analogWrite() function
  • Create a simple LED circuit


 

Parts Required:


Fritzing Sketch


The diagram below will show you how to connect an LED to Digital Pin 10 on the Arduino.
Don't forget the 330 ohm resistor !
 


 
 

Arduino Sketch


The latest version of Arduino IDE can be downloaded here.
 
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/* ==================================================================================================================================================
         Project: 5 min tutorial: Send Hex from computer to Arduino
          Author: Scott C
         Created: 21th June 2015
     Arduino IDE: 1.6.4
         Website: http://arduinobasics.blogspot.com/p/arduino-basics-projects-page.html
     Description: Arduino Sketch used to adjust the brightness of an LED based on the values received
                  on the serial port. The LED needs to be connected to a PWM pin. In this sketch
                  Pin 10 is used, however you could use Pin 3, 5, 6, 9, or 11 - if you are using an Arduino Uno.
===================================================================================================================================================== */

byte byteRead;                   //Variable used to store the byte received on the Serial Port
int ledPin = 10;                 //LED is connected to Arduino Pin 10. This pin must be PWM capable.  

void setup() {
 Serial.begin(9600);             //Initialise Serial communication with the computer
 pinMode(ledPin, OUTPUT);        //Set Pin 10 as an Output pin
 byteRead = 0;                   //Initialise the byteRead variable to zero.
}

void loop() {
  if(Serial.available()) {
    byteRead = Serial.read();     //Update the byteRead variable with the Hex value received on the Serial COM port.
  }
  
  analogWrite(ledPin, byteRead);  //Use PWM to adjust the brightness of the LED. Brightness is determined by the "byteRead" variable.
}    


 


 
 

Processing Sketch


The latest version of the Processing IDE can be downloaded here.
 
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/* ==================================================================================================================================================
         Project: 5 min tutorial: Send Hex from computer to Arduino
          Author: Scott C
         Created: 21th June 2015
  Processing IDE: 2.2.1
         Website: http://arduinobasics.blogspot.com/p/arduino-basics-projects-page.html
     Description: Processing Sketch used to send HEX values from computer to Arduino when the mouse is pressed.
                  The alternating values 0xFF and 0x00 are sent to the Arduino Uno to turn an LED on and off.
                  You can send any HEX value from 0x00 to 0xFF. This sketch also shows how to convert Hex strings
                  to Hex numbers.
===================================================================================================================================================== */

import processing.serial.*;           //This import statement is required for  Serial communication

Serial comPort;                       //comPort is used to write Hex values to the Arduino
boolean toggle = false;               //toggle variable is used to control which hex variable to send  
String zeroHex = "00";                //This "00" string will be converted to 0x00 and sent to Arduino to turn LED off.
String FFHex = "FF";                  //This "FF" string will be converted to 0xFF and sent to Arduino to turn LED on.

void setup(){
    comPort = new Serial(this, Serial.list()[0], 9600);   //initialise the COM port for serial communication at a baud rate of 9600.
    delay(2000);                      //this delay allows the com port to initialise properly before initiating any communication.
    background(0);                    //Start with a black background.
    
}


void draw(){                           //the draw() function is necessary for the sketch to compile 
    //do nothing here                  //even though it does nothing.
}


void mousePressed(){                   //This function is called when the mouse is pressed within the Processing window.
  toggle = ! toggle;                   //The toggle variable will change back and forth between "true" and "false"
  if(toggle){                          //If the toggle variable is TRUE, then send 0xFF to the Arduino
     comPort.write(unhex(FFHex));      //The unhex() function converts the "FF" string to 0xFF
     background(0,0,255);              //Change the background colour to blue as a visual indication of a button press.
  } else {
    comPort.write(unhex(zeroHex));     //If the toggle variable is FALSE, then send 0x00 to the Arduino
    background(0);                     //Change the background colour to black as a visual indication of a button press.
  }
}
    


 

The Video


 


The tutorial above is a quick demonstration of how to convert Hex strings on your computer and send them to an Arduino. The Arduino can use the values to change the brightness of an LED as shown in this tutorial, however you could use it to modify the speed of a motor, or to pass on commands to another module. Hopefully this short tutorial will help you with your project. Please let me know how it helped you in the comments below.

 
 



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