Bot shop EL wire how to

Bot shop EL wire how to

Electroluminescent wire – EL wire how to

Yes, it looks impressive that is for sure! But it might seem a bit daunting to newcomers…… it is not. There are only a view things you need to know.

In the past, you needed to be quite skilled to use lighting to set moods, use in displays, in home decor and so on, now it became easy. In this EL wire how to you will learn everything you need to be an expert in electroluminescent products and it will take you no more than 15 minutes to learn.

Some quick technical stuff

el wire how its made

It is actually quite simple to understand. By introducing very low alternating current (but high voltage) to a layer of phosphor the phosphor will glow. Phosphor when glowing has an aqua blue colour.

To get different colours of EL wire a coloured plastic sleeve is used on the outside of the EL product. This is how EL product manufacturers can produce different colours

el wire colours

The colours are limited to 10 colours: Aqua (fluorescent blue), Lime (fluorescent green), red, blue, green purple, orange, yellow, pink and white

The way to introduce electricity to phosphor can be seen in the first picture above, you take a  piece of copper wire and coat it with phosphor, then you take 2 very fine wires and turn it around the phosphor coated wire like a spiral over the whole length of the wire. You now put the one wire of a power supply and connect it to the phosphor coated copper wire and the other wire of the power supply you connect to the 2 thin wires.

The power source – inverter

One of the reasons we did this how to is because there is a lot of confusion around the power requirements for electroluminescent. The first thing to know is that EL products operate best at a Voltage of between 80V-140V (120V is optimum).

WHAT? Electroluminescent (EL) PRODUCTS OPERATES AT 120V, THAT CAN KILL YOU!!! LUCKILY THERE ARE NEARLY NO AMPS SO IT IS SAFE. 

If you touch bare open wires you might feel a very slight shock – so the connection points should never be exposed. Later in this how to you will see how to make your own connections (if you do not get pre-made el products with connectors already on them) and cover the bare wire with heat shrink tubes, We sell both types in our shop here.

The power source alternates the voltage at around 800 Hz. That simply means it first sends + voltage to the one EL wire and negative voltage to the other side and then switches the – and + voltages around, what is impressive is that it does this switching 800 times in a second, That’s fast!

To make this long story short – you need an EL inverter.
IMPORTANT. Inverters have different power ratings. The lower the power rating the smaller the length of EL wire it can handle. A small inverter is usually able to handle about 3 meters. You do not have to turn it into rocket science, you just need to be “nearish” to those specs, All inverters have a description on what length of EL wire it can drive

So be careful with this though, don’t use a short piece on an inverter that is meant for longer pieces, your EL product’s life expectancy will be drastically shortened. So basically if you have 3 meters or lower use a 3meter inverter rather, it will last longer

Power efficiency, heat and life span.

How long will it run from a battery and how many hours of light will it produce. EL products are very power efficient because of the low amps (current) it uses. There is no other light source this efficient.

Two AA batteries driving 3 meters of EL wire will last 10 hours plus!
No heat is produced at all, cold to the skin
EL wire life span is about 8000 hours, if you have it on every night it will last 1000 days

Using EL wire

El wire can be shaped any way you like. You can also cut it shorter and if you like you can put on connectors on the offcuts (more about that soon)

Becuase the EL wire got a plastic casing you can use PVC glue to glue it anywhere. For wearables like shirts and hats, you can sew it to the wearable by sewing a “loop ” around the EL wire and the piece of fabric. There are no hard and fast way on how to stick it to stuff, above is only ideas

Cutting and putting connectors on EL wire.

Easy as pie. Below is a video that shows exactly how to do that. You will need a soldering iron, solder and a wire stripper (or Stanley knife) we sell an El solder kit here that include the connectors, shrink wrap tubes and end caps. They use a heat gun in this video to shrink the tubes but a lighter will work great as well.

It is important to note that when you cut EL wire the end that is cut of must be isolated in any way you like so that the copper wire and 2 thin wires do not touch each other.

 

 

And that concludes this EL wire how to. So, head over to our EL wire shop category here, get some EL wire and accessories and create some fun stuff.

Our Lithium Battery Charging module review

Our Lithium Battery Charging module review

Lithium Battery Charging module

Lithium Battery Charging module

There will come a time that you want to have your project mobile. The easiest way to accomplish that is with batteries and if you want to get a bit fancy, rechargeable Lithium batteries.

I am reviewing the lithium Battery Charging module that is also available from us here. It is a low-cost unit that is affordable enough to build into your projects directly without having to worry to open a box, removing the batteries for charging and then put it all back again. Except for saving on the cost of a charger you now have an easy to charge project.

Power to the board.

It comes with a USB connector to connect to a 5V power source. This is handy because you can connect the module to a computer USB port or a 5V power supply, your cell phone power supply will work great. This module also has a place to solder 5V power supply power wires directly to the board as well.

Functionality

Lithium charger functions

From the picture above you can see the 2 status LEDs on the Lithium Battery Charging module. The charge LED indicates that the battery is charging and the second LED lights up when the battery is fully charged.

Most of the work is done by the TP4056 IC, it is a constant-current/constant-voltage linear charger IC designed specifically for Lithium ion batteries and comes with many features including automatic recharging and is able to supply 1A charging current! You will find these chips in cell phones, cameras, charging doc stations etc.

Hooking it up is easy, supply the Lithium Battery Charging module with 5V and then hook up the battery via 2 wires to the bat+ and bat- power through holes on the board (this require soldering).

Specifications

  • Input voltage: 5V
  • Maximum charging current: 1000 mA
  • Charge cut-off voltage: 4.2 V + / – 1%
  • Battery overcharge protection voltage: 2.5 V
  • Battery over-current protection current: 3 A
  • Input interface: Micro USB or 5V to power terminals
  • Dimension: 2.6 x 1.7 cm

Changing the charging current

Out of the box, this unit supply 1A constant current to the batteries but that might be too high. It is recommended that when you charge a battery you should charge them at 37-40% of the battery capacity(in mAh). If you are charging a battery of 1000mAh capacity, you should adjust the resistance in a way that the current offered is approximately 370mA-400mA.

Now, this is my only drawback in using this module, you will need to manually replace the resistor. It is an easy process but still a bit of extra work to get exactly the amps you require. I was hoping for a variable resistor but the problem with this is that you will blow the chip if you set the resistance too low, that you will do very easily if you turn a variable resistor just a bit too far to the wrong side.

In the picture earlier you can see the resistor you need to replace if 1A is too high for your batteries. It is easier than you probably think right now, simply use a soldering iron to heat up both sides of the resistor at the same time to remove, put the new one in place and heat up each side to solder it back in place. If you do not have an SMD resistor use a normal 1/4 watt resistor, cutting the legs as short as you can.

Here is a table to work out the size of the resistor you will require:

Resistor (k)BAT amps (mA)
3050
2070
10130
5250
4300
3400
2580
1.66690
1.5780
1.33900
1.21000

Summary

Cheap, easy to use and it can charge bigger Lithium batteries than expected with ease. With the drawback of having to solder in a different resistor to get the correct charging current comes the benefit of being able to charge any chargeable Lithium battery at its optimum levels.

Wifi Scale project for Wemos D1 board Part two

Wifi Scale project for Wemos D1 board Part two

wemos d1 project

Scale project for Wemos D1 part 2- from pallet wood 

Now that we got the scale to work with an Arduino it is time to see how we will get it to work with a Wemos D1 board so that we can view the scale data from a Wifi connection on a web browser. This can also be a web browser on a cellular phone if you so wish. In short, we want to now expand our project to an IOT (Internet of things) scale. This scale project for Wemos D1 part 2 focus on the wifi part of this project, in part one we focus more on the load cells and amplification so first have a look (there is a link above).

Getting the D1 to work with the Arduino IDE.

In our review of this board, we gave details on how to get it to work with your Arduino IDE in the “Use your Arduino IDE to program the chip” section.

To recap:
  1. To install drivers remove all previous esp boards download and
  2. install http://www.arduined.eu/files/CH341SER.zip
  3. next open file>preferences
  4. enter http://arduino.esp8266.com/stable/package_esp8266com_index.json in the additional board manager urls area
  5. open tools>board>board manager
  6. search ESP8266 and
  7. install “esp8266 by ESP8266 community” version “1.6.5-947-g39819f0”
  8. next restart the Arduino IDE then select
  9. tools>board>WeMos D1 R2 & mini
  10. select upload speed at 115200 baud

 

Scale project for Wemos D1 – Hooking up the load cell HX711 amplifier

In part one of this project, we showed you how to connect the load cells to the amplifier board as well as to an Arduino Uno. We also talked about the pin differences between the Arduino and Wemos D1. Below is a picture again as well as a diagram connecting the amp to the Wemos board.

In the code, we also show, as comments in the pinouts for the Arduino.

Wemos D1 pin assignments

Wemos diagram

The LCD screen pinout can also be seen in the code.

LiquidCrystal lcd(0, 2, 4, 14, 12, 13); // WEMOS pins differ from UNO pins translated to uno would be (8, 9, 4, 5, 6, 7)

Scale project for Wemos D1: Explaining the code

Connecting to your WIFI network

To connect to a WiFi connection we use these 2 libraries (all the WiFi libraries will be automatically installed with the ESP8266 files when you add the board to your Arduino IDE):

#include <ESP8266WiFi.h>
#include <WiFiClient.h>

Next, you need to enter your WiFii details to connect to the network. Look for the lines below in the code and change the **** with your network name and network password.

const char* ssid = "*********"; 
const char* password = "*******";

Setting up the board as a web server

The first thing to understand is that we want to setup the D1 as a web server. If you are not familiar with web servers it basically means that we want to hand out web pages to web browsers for displaying when the web browsers connect to the D1 board. Hence the name web server – it serves web pages to your browser when the browser connects to it.

In the code (see below) you will use a library called ESP8266WebServer.h and the code to start the web server is simple:

ESP8266WebServer server(80);

The (80) specify the port the server should listen to and is standard as all web browsers by default try to connect to web servers on port 80. A port is nothing more than a number that distinguishes what data is intended for what application on a server. Thus, a web browser will connect to the web server and communicate that it wants to connect to the software that is assigned the number 80. Port numbers are of cause very important when you have many applications like FTP, email etc on one server,  else there is no way you will know for what application the data to your server is for.

Web page code

A web page is a text file with very basic code in it, this code is called HTML, In short, HTML code tells your web browser how to display and what to display on the web browser. It tells your web browser things like the size, font and colour of the text, where to find the images in the web page, where on the page the images must display and so on. (Note, that the images are not “in” this text file but rather a link to where the browser will find it on either the Internet or in the web servers file directory). A web browser thus “understand” HTML code and will generate the page you see in the web browser according to this code.

Here is an example of HTML in the code we will use soon:

webString=”<html><head><meta http-equiv=’refresh’ content=’3′> </head><body>Weight: “+String((float)value)+”kg</body></html>”;

This image below is what you will see in your web browser:

browser view plain

In short all web page code start with <html> and end with </hml> . We then have the <head> tag that gives your browser information like the name of the page and so on, in the example above we use the “refresh” tag that tells the web browser to reload the page, in this case, every 3 seconds. This is required because we want the web page to refresh by itself so it will display the weight of the scale when the weight changes. The <body> tag tells the browser what it should actually display in the browser window and the </body> tag tells the browser when the end is reached of what should be displayed.  In between the body tags we display the Weight from the scale in the browser.

If you spice up your HTML knowledge a bit you can make it look better. I added a picture and some other formatting to the code so it shows our logo.

webString=”<html><head><meta http-equiv=’refresh’ content=’3′> </head><style>body {background-color: #cccccc; font-family: Arial, Helvetica, Sans-Serif; Color: #000088; }</style><body><img src=’https://www.botshop.co.za/wp-content/uploads/2017/03/logowebsite2.png’><br><b>Weight: “+String((float)value)+”kg</body></html>”;

Here is the result:

browser view formatted

Connect to the D1 web server

Once your server is running use your web browser to connect to the D1. In the URL field in your web browser type the IP address (see below on where to get it) of your web server and press Enter. In our code, we created an additional page called test. To get to it use your ipaddress/test e.g 192.168.0.1/test

Get your IP from serial monitor. We simply used the code below to get the IP address you should connect to and that will display in serial monitor for you to know what the IP is. You can also display it on the LCD display if you so wish.

Serial.print(“IP address: “); // displays ssid and IP on serial monitor and also IP on LCD
Serial.println(WiFi.localIP()); //

Code

#include <ESP8266WiFi.h>
#include <WiFiClient.h>
#include <ESP8266WebServer.h>
#include <ESP8266mDNS.h>
#include <HX711.h>
#include <LiquidCrystal.h>

LiquidCrystal lcd(0, 2, 4, 14, 12, 13); // WEMOS pins differ from UNO pins translated to uno would be (8, 9, 4, 5, 6, 7)

#define DOUT 16 // uno pin 2
#define CLK 5 // uno pin 3

float value;
String webString=””;
#define calibration_factor 21900 // Do Not change unless other load cells are used
HX711 scale(DOUT, CLK); // initialize load cell amplifire

const char* ssid = “*********”; // function as metioned in bellow comments
const char* password = “*******”; //

ESP8266WebServer server(80); // starts server on port 80

const int led = 13;

void handleRoot() { //
digitalWrite(led, 1); //
server.send(200, “text/plain”, “please enter correct page”);
digitalWrite(led, 0); //
char temp[400]; //
} //

void handleNotFound(){ //
digitalWrite(led, 1); //
String message = “File Not Found\n\n”; //
message += “URI: “; //
message += server.uri(); //
message += “\nMethod: “; //
message += (server.method() == HTTP_GET)?”GET”:”POST”; //
message += “\nArguments: “; // typical error 404/page not found
message += server.args(); //
message += “\n”; //
for (uint8_t i=0; i<server.args(); i++){ //
message += ” ” + server.argName(i) + “: ” + server.arg(i) + “\n”; //
} //
server.send(404, “text/plain”, message); //
digitalWrite(led, 0); //
} //

void setup(void){
pinMode(led, OUTPUT);
digitalWrite(led, 0);
Serial.begin(115200);
WiFi.begin(ssid, password);
lcd.begin(16, 2);
Serial.println(“”);
scale.set_scale(calibration_factor); // calibrate scale
scale.tare(); // zero scale
/*
while (WiFi.status() != WL_CONNECTED) { // I have disabled this to allow client to play with device,
delay(500); // What this does is it waits for the WiFi to be connected
Serial.print(“.”); // and while waiting it displays which ssid it is trying to
lcd.setCursor(0,0); // connect to I was thinking to add a script to show all
lcd.print(“Connecting to”); // available ssid’s so the client can select which one to use
lcd.setCursor(0,1); // using the keypad on lcd shield and also enter the password
lcd.print(ssid); //
} //
delay(750); // allows enough time to see that its connecting
*/
Serial.println(“”); //
Serial.print(“Connected to “); //
Serial.println(ssid); //
Serial.print(“IP address: “); // displays ssid and IP on serial monitor and also IP on LCD
Serial.println(WiFi.localIP()); //
lcd.setCursor(0,1); //
lcd.print(WiFi.localIP()); //

if (MDNS.begin(“esp8266”)) {
Serial.println(“MDNS responder started”);
}

server.on(“/”, handleRoot); //home page

server.on(“/test”, [](){        //enter IP followed by /test
char temp[400]; //to display scale value
value=scale.get_units(), 0; //
webString=”<html><head><meta http-equiv=’refresh’ content=’3′> </head><body>Weight: “+String((float)value)+”kg</body></html>”; //this line has an automatic refresh built in it is also the string to display the value
server.send(200, “text/html”, webString); //
}); //

server.onNotFound(handleNotFound); // 404 error

server.begin();
Serial.println(“HTTP server started”);
}

void loop(void){
server.handleClient(); // monitors user interaction on web
value=scale.get_units(), 0; //
lcd.setCursor(0,0); //displays scale vallue and ip on lcd
lcd.print(“Wheight: “); //
lcd.print(value); //
lcd.print(“kg”); //for some reason this jumps around alot
delay(1000); //
}

scaleCode text file