Let’s transfer the control on the Web
With the last implementation step remote access to our board is gained: as we have already seen, we will take advantage of RandA’s web server (Tomcat), in order to give visibility to the html pages that we want to make publishable on remote clients. Consequently, at an installation level we just have to worry about putting them in the folder below:
/home/apache-tomcat-7.0.47/webapps/RandA/
from where Tomcat will take it to transfer it to the client requiring it.
The page specifically created for this application, that we called IRConsole.html, may be seen infigure: the graphical style has been set along the lines of other web pages that have already been created for RandA’s remote control. Moreover we added its reference on index.html (that allows to open other pages by means of the applications for RandA’s remote management) as well, so that it may host the connection to our IRConsole.html.
Once the pages have been loaded in the abovementioned folder, we may immediately verify that they are properly working, by means of a PC that is connected to RandA’s local network, and by typing in the browser’s address bar: http://<Indirizzo IP RandA>/RandA/IRConsole.html,
<Indirizzo IP> here stands IPv4 address of RanA’s board within the LAN. The page shown in figure, should then be loaded, and as we already said it corresponds to the IRConsole.html file that we loaded previously.
The first key may be immediately noticed on this page, it is connected to the serial communication: it is needed to activate the communication channel, from the servlet to the /dev/ttyS0 serial port (and therefore to Arduino). Therefore, it is the first thing to activate, and then we have to wait that the window on the side will state “open”. It is worth to remember that Arduino’s serial port is also used for programming, thus if we activated the communication with the web page we cannot program the board and vice versa. In order to avoid leaving the serial port uselessly busy, it would also be a good practice to remember turning off the the interface (by using the key again), before leaving the web page.
Immediately under that, we placed a list of the keys corresponding to the various channels in our virtual remote control; speaking of which it must be said that it is possible to add more of them (and up to 127) and maybe to customize their names, so that they may describe the associated function (for example, “turn on the air conditioner” instead of “Channel 1”). To do so, the IRConsole.html file must be edited, and the code between the two comments, <!–Channel list begin –> and <!– Channel list end –>, must be modified. To change the name, it is enough to change the relative field, “value”. For the sake of clearness, the procedure needed to add the buttons is described separately within this same article (in the box named “How to add channels to our remote control”).
After the list of the keys/channels, there is the “Processing status” box, that relates the outcome of the communication with RandA: for every command given, it will show “wait” while waiting the reply, “fail” if the command was not executed or if Arduino didn’t reply within a certain time (there is a timeout on the SerialIO servlet), or “OK” if the command was successfully executed. By going down in the web page we encounter two buttons we will describe below.
- Get room temperature: for each “click” it updates the temperature value detected by the DS18B20 sensor that is found in the shield. This information can be useful if we use ArdIR to control the home air-conditioner. Please keep in mind that at the first query, since there are no valid conversions yet, it might show the default value (85°C): do not worry, but click again.
- Arduino reset: it forces a reset in Arduino’s micro. In the case of (unlikely) need, it enables the “restart” of the sketch.
The “HOME” link, finally, has been “borrowed” from other RandA’s web pages, and allows to return to the home page shown in figure.
It is quite easy to replicate an infrared remote control’s code, by using a few components and an Arduino board. On the other hand, by using RandA, other possibilities are added, such as the Web access and the remote control.
Originally published at Open Electronics website.
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