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Simple and intuitive web interface for your Raspberry Pi

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     The Raspberry Pi is an amazing 35 dollars mini-computer. It allows you to do everything you could do with a regular Linux computer (Connecting to the internet, watching videos, launching applications, ...) but also to interact with the world surrounding it, just like an Arduino. That's why I qualify it as a mix between a computer and a micro-controller.
     That's also why I chose it for this project. I'm going to show you how to control LEDs with your Raspberry Pi. Firstly directly from the Raspberry Pi itself, then from any device in your house like your Smartphone or your tablet.
 
Here is a very good example of what you can achieve after reading this Instructable: http://www.instructables.com/id/Web-Controlled-8-Channel-Powerstrip/. Thanks to Rleddington for his amazing project.

 
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Step 1: The electronic part

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     The electronic part is nothing special, it's only 8 LEDs with their protecting resistor. The only hard part is to connect the LEDs to the good pin on the Raspberry Pi. Indeed, I'll be using later a library called Wiring Pi made by Gordon Henderson (You can visit his website at: http://wiringpi.com/) and the pin's numbers used in this library aren't the same than the ones on the Raspberry Pi. See this page for matches: http://wiringpi.com/pins/ (just be careful about your Raspberry Pi revision, the pinout isn't exactly the same). I'll be using Wiring pins 0 to 7.
     Concerning the resistors, they should be 270Ω but since I don't have this precise value, I'm using 560Ω resistors (LEDs are just less bright).
     Finally, I've made two schematics to make it simpler. The first one (with the complete Raspberry Pi) is showing you the real pins as they are shown on the board. The second one is a simplified version, it's showing you only the useful pins and their matches in the Wiring Pi library (GPIO Wiring number/Actual number on the board).
Hayaalsh18 days ago

Hello TheFreeElectron :)

Thank you for this amazing tutorial!
but I have a question. One of the members said that they
can control the LED lights from New-Zealand! However, I cannot control the pi
unless the pi and my Smartphone are connected to the same network.

Is there any way to control the pi
from any place in the world without the need of being connected to the same
network?

I hope you get what I mean.

please answer me :(

Hayaalsh17 days ago

Hi again,

I have another 2 questions:

Can I use LED light bulb instead of those small LED lights?

And can I control things other than light? like a small motor? or it would require more power?

justcus28 days ago

I am unable to download

You can download the full project at: http://www.mediafire.com/download/1rgs4t52o8ptd5r/Web.zip

Any help would be greatly appreciated!

TheFreeElectron (author)  justcus28 days ago

Hi Justcus,

It still works for me. A further description of the problem would be useful.

I have tried to download the web.zip file using IE11 and Google Chrome but to no avail. When I click on the download button, I am usually directed to another site and it downloads other files that I am suspicious of. Other times I get "This Page Can't Be Displayed. Is there another way to get the file?

Thanks,

TheFreeElectron (author)  justcus26 days ago

Hi Justcus,

I've tried downloading the file on other computers and platforms, all of them worked. It's maybe a network configuration problem. Have you tried the other links in the comments?

Hi TheFreeElectron,

I forgot to applaud you on the great project. I have it working up to the point of setting up the iPhone or Android to control the Raspberry Pi. I don't know crap about programming these days so the step by step was great. I last programmed in assembler and BASIC for the 8080A (1976) after that it was all appliance computing.

I tried one other the was on mediafire.com/download/xxxx/xxx.zip and had the same problem. Maybe it is my firewall or antivirus. My pea brain just doesn't work so good anymore. Can the file be placed in dropbox or can it be downloaded from a ftp site. As far as my network configuration I think it is OK I have downloaded files from other sites without any problems. The older I get the more about computers I have forgotten. CRS!

Thanks,

TheFreeElectron (author)  justcus23 days ago

Hi Justcus,

Definitely you won't stop harassing me (just kidding, there's no problem). Thank you for your comment, that's always interesting to exchange experiences and thoughts with others, writing this 'Ible was a real pleasure and finally, knowing that some people actually learned something by reading what I wrote is an even greater pleasure. By the way, I wasn't even born in 1976 and I've never heard about the 8080A. ;)

Concerning your problem, I didn't take the risk of another website not to work so I added a new "last" step in which I pasted the whole code and uploaded the different pictures.

Cheers,

TheFreeElectron

Thanks so much for the finishing touch!!!

When you don't have anything to do, look up IMSAI 8080. That is where it all started for me. Keep up the excellent work!!!

Again thanks,

kounenos29 days ago

Hey TheFreeElectron,

First of all thanks for this nice Tutorial it helped me a lot with web interface! i 'm new in web interface and i try to upload the files in /var/www with WinSCP and tells me

Permission denied.
Error code: 3
Error message from server: Permission denied

you can help me a little?

TheFreeElectron (author)  kounenos29 days ago

Hi Kouenos,

This problem is surely caused by the fact that the user you're connecting with (probably pi) isn't owning the www directory (therefore doesn't have read/write rights in it). You need to use the command "sudo chown -R pi /var/www" if pi is your user.

If this is not the cause, I do not see other possible reasons, maybe a configuration problem. Try the "ls -l" command to check who's having the rights on this folder.

Hope I helped,

TheFreeElectron

motzer1 month ago
Hey TheFreeElectron,

first of all thanks for this nice Tutorial - it helped me a lot! I am using your start to controll som Remote sockets. There is a little problem with my web programming skills =) So the Problem is to switch one socket on you have to set two GPIOs High for a short amount of time (~1sec) and then one of these Ports has to bet set Low again after this second. And tried it now for hours but no solution.

Little Example what I tried in the javascript file:

var new_status = change_pin ( 0, 0);
var new_status = change_pin ( 4, 1);
setTimeout(change_pin( 4, 0),1000);

So Pin 0 and 4 are the two GPIOs to set, but Pin 4 has to be toggled after one second. With this code it works sometimes and sometimes not on clicks so sometimes Pin4 is set LOW and sometimes not. Do you have an idea or a advice for me to solve this "small" Problem?

PseudoCode
Set Pin 0 and 4 High
Change Button0 Picture to Green
wait 1 secodn
Set pin 4 Low again

Cheers,
Ben
TheFreeElectron (author)  motzer1 month ago

Hi Ben,

Thank you for your comment and your feedback, I really appreciate.

As I understood your idea, you push one button to turn high two GPIO ports, then 1 second after, one of the two ports is turned low. Correct me if I'm wrong.

I'm not really a pro of JavaScript but you're setting the new_status variable to what the change_pin function returns for (0,0) then for (4,1) without doing anything between or after. You're also setting the pin 0 to 0 <=> LOW (first line). That's what I can say about your code example.

After that, dealing with the delays as the client doesn't seem, to me, a good idea. You can do this in the PHP script using the sleep( TIME_IN_SECONDS ) function. Or by using the method I described in several comments below (using a python daemon and a PHP page to make the link). Here's an example I wrote for another 'Ible: http://www.mediafire.com/download/p88afnrybdmxsu6/... It isn't including a delay but it's still very interesting to understand the method. You just need to run the gpio_server.py file and to put the rest in your www folder. I also corrected several bugs and "upgraded" the way the project works. Again that's just a personal opinion and using JS is also a good idea.

Hope I helped, do not hesitate If you have any other questions/problems.

Cheers,

TheFreeElectron.

ainsey111 month ago

Hi ThefreeElectron,

First of all - what a brilliant 'ible. I think this is great for any fun little project :)

However I get PHP errors when running /gpio.php - it comes back with fail. also index.php just gives me a blank screen.However when i rename the file from .php to .html I get a black screen with a missing picture symbol...

I have copied the files from your Web_simple folder into the root of /var/www.

my lights also change when I issue for i in 0 1 2 3 4 5 6 7 ; do gpio write $i 1; done

Am I missing something obvious?

Cheers,

Ainsey11

TheFreeElectron (author)  ainsey111 month ago

Hi Ainsey11,

Thank you for your comment, I really appreciate your feedback!

Concerning your problem(s), I can only give several clues:

  • Firstly, you can't run gpio.php alone, it needs parameters sent through the URL. You get a "fail" because of the protection I put to be sure the user did input values, therefore you should type something like "gpio.php?pin=PIN_VALUE&status=CURRENT_STATUS".
  • I do not see why you would get a blank screen when running index.php. However, it seems you're running the pages with the php program in a command line. If it's true, it may be the problem.
  • Renaming the file to .html will tell the server NOT to execute the php code, that's probably why the pictures are missing.
  • Finally Web_simple is a modified version of the original script I made for Singhdeolji and I haven't tested it, he may have done several modifications for it to work but I don't think it's the case.

That's all I'm thinking about now, I'm maybe missing something too but it's hard to solve problems hundred (maybe thousands) of miles away ;) If it still doesn't work, keep trying and try to understand why, but I hope it will.

Cheers, TheFreeElectron.

Hello TheFreeElectron,

Good news! I have managed to get it working :) I spotted that on line 25 you had a random } as soon as I removed this it all worked fine. However when running the web page I can only see one button (see image) This button works perfectly but I have no idea how to add the other 7, would you be able to assist?

Have a great day,

Ainsey11

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TheFreeElectron (author)  ainsey111 month ago

No problem, it was a pleasure.

Keep going, there are a lot of possible things to do with this simple project ;)

Cheers, TheFreeElectron.

Hi Again,

All is working again :) I didn't spot the full web.zip folder..

Great 'ible- thanks for all of your help, keep it up :)

Thanks,

Ainsey11

I think this is my first comment on instructables, but I really think that this is a great tutorial and just wanted to say great job. Thanks for the instructable! Cheers, Jeff.

TheFreeElectron (author)  jeffpagnutti1 month ago
Hi Jeff,
Thanks for your comment, I'm glad you liked my Instructable!
Don't hesitate if you have any question.
Cheers, TheFreeElectron.
nicolluch2 months ago

great project! only if a can walk through my ignorance to make it work!

I can't put the server to work. working with att dsl modem -> router -> cat5 to pi. I have internet on pi.

I'm getting my ip with 'what's my ip on' google, then write that on the browser, and it doesn't find it.

already tried everithing you suggest, on two SD cards and not wirking, really frustrating!

Any ideas? thanks again!!

TheFreeElectron (author)  nicolluch2 months ago
Hi Nicolluch,

Your problem is in fact really simple, what I'm doing in this 'Ible is accessing the Rpi over my house's local network. That's why the ip address looks like 192.168.1.xx. If you want this ip, just take a look at your router's page (generally by typing 192.168.1.1 in your browser) or type the "ifconfig" command in your Rpi's command line.
In fact each device in your house is having two ip's. The LAN ip (Local Area Network) which is the ip of your device in your local network. Then there is the WAN ip (Wide Area Network), this one is in fact the ip of your router and therefore is the same for all the devices in your house. What you're getting when using services like "whatismyip.com" is the wan ip.
If you want to access to your Rpi over the Internet, you first need to forward the http port (or any others) to your Rpi. It means that when someone will try to connect to your WAN ip, the request will be redirected to your Rpi. Then you can access to your Rpi over the Internet.

Hope I solved your problem, TheFreeElectron.

Thanks! I was half way there, now it's working!

I'm on the hardware side, working on a home automation system, if you need anything, let me know.

thanks again

TheFreeElectron (author)  nicolluch2 months ago
No problem, it was a pleasure.
I hope to see soon an 'Ible of your Home automation system. ;)
NiBa2 months ago

This is awesome, thanks!

BTW, I would like to know some more about this nice project and I have two questions here:

I did everything similarly as in your tutorial, but my leds are on when they should be off so the operation of them are inverted somehow?

I'm totally new with javascript and php so sorry if I'm disturbing. It would be great if there is some way to change the turn on action of the led so I could generate just a one pulse by clicking on and another pulse when turning off. With this it would be possible to control devices with the pulses. What I'm trying to explain, raspberry gpio signal stays up until on or off is clicked.

TheFreeElectron (author)  NiBa2 months ago
Hi Niba,
No problem, thanks for your comment.
To answer your first question, I do not see why a problem like this would happen. You should use the developer's tools of your browser to see what you're sending when clicking one of the button then what you're receiving. The fact that the LEDs are inverted may signify that the first inversion happened when generating the index page. You should therefore check the source code of that page to see what is the value of the "alt" variable. However, it's hard for me to resolve this kind of problem without having it in front of me.
Concerning your second question, that wouldn't be a problem since everything is done by the gpio.php page, you would just need to modify the code and/or the different commands to do whatever you want. The Gpio Utility is allowing you to do nearly whatever you would like to do. This method is however very slow when it comes to complex things. You should check the "Python daemon" method I described in some other comments, it's a lot faster and safer.

Do not hesitate if you have any other questions, you're not disturbing, far from it. It's really interesting for me to get feedback from other members.

Have a good day, TheFreeElectron.
singhdeolji3 months ago

First of all i must say " great work!!!!!", I am new to php/javascript or even html for that matter, i have been trying to understand your project and try to dumb your project down to a single html button, which turn a led on [or something even more basic]. If its not too much to ask..... perhaps a little example code. thx in advance.

TheFreeElectron (author)  singhdeolji3 months ago

Hi Singhdeolji, Thanks for your comment.

Concerning the code, I'll try to explain it to you then I'll give an example. The first thing to do is to generate the buttons of the index, I'm using php code directly inside of the home page. After that, the JavaScript watch if you are clicking one of the buttons, if you are, it sends a request the gpio page. This page is then receiving the number of the LED you wanna change then executing the same code you would be executing yourself in a terminal. Finally, this page is sending back the status of the LED, the JavaScript reading this status then updating the button's color in function of it.

Here's an example for one button but I haven't tested it: http://www.mediafire.com/download/2z3h7g4yjeoc7be/...

Hope I answered your questions,

TheFreeElectron

Thx for the quick reply man!!!
Every thing is running smooth, i put you files in the www folder, went to the browser, even on my phone + even my cousin sitting in Newzeland turn the led on off.
[but every thing is too magical if you kw what i mean............]
So i figured i need to understand the php & ajax relationship here first to get a grasp on things. So after doing some research, i came up with code where i have a php.code, html.code.
In the html code i have the input "text" & "submit". and also the httprequest function(). The function takes what I type in the html text area, and set it to a variable. then the var gets send to the php file(using POST instead of GET, not so sure abt either of them). I also have a html div tag and its name ="status", which display responsetext (returndata =http.responseText) from the server.
like- document.getElementById("status").innerHTML = returndata;

In the PHP file, i simple get the text value, put it in a var and add 1 to it. Then echo the result.

So when on my html page i type 1 in the text box, then press submit. i get back a result of 2.
My question is: Why would this approach works or am i missing some very basic like- checking the wrong pin or something else.
<?php

$x=$_POST['text'];

if ($x=='1'){

system("gpio mode 15 out");

system("gpio write 15 .$x.");

system("gpio write 15 0")

}

?>

If i run the php file from the command line(php filename.php) taking out the first two lines it works,[ pi's(pin 8)== gpio(pin 14) == wiring pi(15) ]
But when i run it through the browser nothing happens.

TheFreeElectron (author)  singhdeolji3 months ago
No problem, it's a pleasure to know that your cousin can now turn your LED on/off from New-Zealand. ;)
So as I understood, you are using a text input and a submit button which is managed by a JavaScript "script". This one sends the input to a php code which is executing the commands then sending back the value and finally the JavaScript is modifying the content of a textarea in function of this.
I see no possible errors in using this method so the problem should be somewhere in the code.
1) I don't know if it's an error you made when typing the message or a real error, but the $x of the 5th line shouldn't be within the quotes, rather like system("gpio write 15 ".$x);
2) Are you sure about the type of the variable or the value itself? You should add more tests at the beginning of your php code.
3) You should install a Wamp server on your computer (or Xamp/Lamp depending on your OS). It is very useful since the errors are displayed and it tells you why your code isn't working. It would therefore allow you to debug the part of the code which is receiving and using the variable. You would just have to comment the lines working only on the Rpi (system,...).
4) You are turning off the LED directly after having turned it on, why not adding a delay.
5) The fact that the code is working when using it in the command line is a little bit weird but it shows that connections are good and that the problem is rather coming from the variable.

Again, it's hard to answer without having hands on the code but I hope you'll find a solution (maybe in this comment ;). Do not hesitate to ask if you have any other question.

Greetings, TheFreeElectron.

PS: If you're still wondering, the difference between POST and GET is easy. GET is transmitting the data via the URL, and POST via the request's body. The only practical difference is that a POST request is harder to build in JS.

just got back from work, decided to give this an another shot!!!!
Its is quite ridiculous that its was just a syntax error. instead of system("gpio mode 15".$x), It needed an space between 15 "
But ya i was so convinced for some reason that this approach was not possible don't know why?
May be i have been quite a history of disappointment and struggle to get something like this to work..
i actually started with using java (only language i kw) to control GPIO pin, i came accross "pi4j" a libraray to control GPIO using java. > Then i want to do it over the network, thats when the struggle begin.
then looked into html>javascript >node.js>+several node.js modules>finally php/ajax
I really appreciate your help man!!!!!!!!
Now need to look into some php IDE's for debugging/errors. I give eclipse a shot, may be a php plugin for it, as i am already familiar with it.

TheFreeElectron (author)  singhdeolji2 months ago
Hi Singhdeolji,
I'm glad to know that your setup is now working (sometimes the smallest errors are the most annoying).
Concerning developing in php/html/JS, I'm personally using Notepad++ and a SFTP client to upload the files. After, I'm also using a Wamp Server on my computer since, as I said it before, it tells you what went wrong (like a debugger) instead of stupidly returning a 500 server error. It is very useful when you are working on a website that doesn't require anything specific to the Rpi. The developer tools of your browser may be very useful too.

Have fun developing, TheFreeElectron.
hxc3 months ago
can u give block diagram?
TheFreeElectron (author)  hxc3 months ago
Hi hxc, Here is one I made quickly:
Block diagram.JPG
thx for the block diagram.....but..i need list of hardware and software for this project....
TheFreeElectron (author)  hxc3 months ago
For this project, you'll need:
*Hardware:
-A Raspberry Pi (obviously)
-8 resistors (270 Ohms or more)
-8 LEDs
-Some cables
-A breadboard

*Software:
-Apache2 Webserver
-PHP5 extension for Apache
-WiringPi library (=>You get the Gpio utility when you build the library)

You'll also need a ssh client and a sftp client on your own computer.
ihrozny3 months ago
hello,
next one great instructable,
i have one question, can be this project somehow changet to "led dimmer" ?
all the functions be the same, eg. web connection, 8ch.. but the dimming mode instead of on/off for each channel ?

Sorry for my english, im only begginer, but hope you understand :)
Ivan
TheFreeElectron (author)  ihrozny3 months ago
Hi Ivan, Thanks for your comment.
As I understood your question, you would like to vary the brightness of each of the 8 LEDs and each LED would be independant.
-The web interface would be changed into 8 sliders (and maybe a submit button to reduce network usage).
-I'm not sure that all the pins support PWM (Pulse Width Modification to vary the brightness) so you may need another chip to add more.
-Concerning the PHP code you can use the "gpio pwm pin value" command (See this page for more information.) but if you are using another chip, you better be running a python script (The wiringPi library has its equivalent in python) waiting for incoming TCP connections and then transmitting the data to the chip, the PHP script would receive the data from the HTTP request and then transmit it to the python script by a TCP socket on the localhost port. Here is a little chain to explain better:
HTML slider => JavaScript => HTTP request => PHP script => TCP socket => Python script => Wiring Pi library => (chip =>) LEDs. The two underlined expressions are the protocols used to transmit data.
This method may seem a lot harder and slower but it is in fact really fast and this avoids commands to overlap (Apache can run two or more php scripts at the same time).

I hope I answered your question and if you have any other request, you can reply or send me a message.
Greetings, TheFreeElectron.

PS: You're not the only one who's learning english ;)

Starman465613 months ago
Thanks for the great instructable. I have been waiting for something like the Pi to come along for years. This project was a great way to get started. I have been interested in home automation, but didn't find equipment that worked the way I wanted. I will have to brush up on my programming and learn php, but that is part of the fun.
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