This project looks at ruggedising (the act of making something more rugged, resistant to shocks and resistant to liquids) an Android tablet so that it can be safely left with a toddler (3 years +). This gives you a fully functioning Android ruggedised/toddler-proof tablet for around €100 as opposed the specialised ones you can buy for that price and up and are usually limited in terms of the software and media you can put on it (also games and other software can be in the region of €30 for each application on top of the original hardware cost). This makes this hack both a cost saving and provides a more flexible software platform that can adapt to your child’s needs as they grow.

The main components are:

• Basic Android tablet (currently under €60) [search A13 or Yeahpad for alternative branding]
• Palm Pixi Plus Touchstone Back Battery Cover (currently under €10 on eBay)
• HP TouchStone Wireless Charging Dock (currently under €10 on Amazon.co.uk)
• Solder and soldering iron
• Plenty of Sugru
• USB micro connector (male)
• 3.5mm audio jack connector (male)
• Insulation tape/Duct Tape
• 2 paper clips
• some super-glue
• some small gauge wire
• a resizeable strap
• micro SD card (optional)

A13 or Yeahpad are alternative search terms for this tablet

We start with a very basic Android tablet. The one linked to above is very basic, but I was surprised with it’s performance when the price is taken into consideration (I even bought another for myself).

The first aim was to make this tablet charge when placed on the HP Touchstone wireless charging dock, an approach that would make it first easier for the toddler to do themselves and secondly wouldn’t be vulnerable to split drink or other liquids that might get on the device (the tablet unlikely to survive being totally submerged). There are two parts to the wireless charging circuit the “Palm Pixi Plus Touchstone Back Battery” and the “HP TouchStone Wireless Charging Dock” both are pictured below.

Palm Pixi Plus Touchstone Back Battery Cover Door inside

Palm Pixi Plus Touchstone Back Battery Cover Door with charging coil and metal position discs exposed

HP TouchStone Wireless Charging Dock

The middle photo above shows the internal charging coil and metal positioning discs (these help align and magnetically align the coil with the dock) from the inside of the Palm Pixi case. It is these components that we are going to transfer into the Android tablet in order to make it charge wirelessly. Remove these parts, being careful not to damage the charging coil (it is just lightly taped down, use a plectrum or similar to slip underneath and peel off). Don’t worry about damaging the case when removing the metal positioning disc as we are going to discard the case. Alternatively to using the metal discs you can replace them with similarly sized neodymium rare earth magnets, this will boost the magnetic attachment for a better holding force (but we are also adding Sugru that will also help hold the added weight of the tablet).

The tablet is easy enough to open up, just use a plectrum/fingernail or phone repair tools to work away the back panel of the tablet, be gentle enough it should easily come away. This tablet can be charged via two sources, the USB connection and a dedicated power jack. I decided to leave the USB exposed but would cover the power jack socket, so this would be where I would attach the wireless charging coil. Once inside remove the main circuit circuit board by first removing all the ribbon cables connectors (you will also need to free the tape holding them) and then the screws.  Locate the power jack and insert the power cable that came with the tablet, now probe (with a voltmeter) the power jack connector on the main circuit board to establish the polarity (positive and negative terminals), make a note of the result. Now do the same with the charging coil, plug in the charging dock and place the coil on it (you may need to temporally stick the metal discs to it so that it stays in place), take the readings from the two metal pads visible in the first image of the Palm Pixi case (see above), again note the polarity. You are now ready to solder the corresponding polarities together (just remove the power cable first, just to be safe). Once this is complete line up the coil on the back panel of the tablet, being mindful of where the dock will be positioned on the far side, make sure the metal discs are oriented in the right position so that the dock aligns with the coil (you may want to secure the metal discs with a double sided tape and or use the original Pixi case for dimensions). The dock should stick to the back panel of the tablet. Add a little tape for strength when complete and you should have something like the picture below.

Wiring up the internal charging coil and positioning the coil

The tablet should now be charging wirelessly

While we are inside the tablet I added some paper clip loops so that I could later add a strap to the tablet so that I could attach it to the back of a car seat for entertainment on long journeys or to secure it in other locations. This was simply achieved by making two small holes (1-2mm holes, 3-4cm apart) in the back panel at either side of the back panel, this can be done easily with a drill, but can also be achieved by twisting a small flat head screwdriver against the plastic. Bend the paper-clips so that they look like the first image below. Make sure that the ends of the paper-clips come together on the inside, then glue these ends together and to the back panel with some super-glue and cover with some tape to insulate them from the internal electronics (see the second image below). Then but the back panel back on.

this is where a strap can be attached so that the tablet may be strapped to the back of a car seat or some other convenient location

Internals with charging coil and paper-clip loop ends

Now it’s time to start ruggedising the device. I started by wrapping the charging dock in cling film (plastic wrap) and placing it on the back panel (where it corresponds with the internal coil, it should “snap” into position anyway). Adding the cling film prevents the dock from becoming attached to the tablet, you can simply peel it off after the Sugru has cured.  I then added Sugru around the dock (see the image below). I also added some Sugru around the speaker, this was a first step to protect the speaker. Let the Sugru cure for 12-24 hrs.

Back View testing the charger position and Speaker first layer protection

Now we are ready to fully ruggedise the device.

Note: after this step you will not (without damaging the protection we are going to apply) be able to open the device or insert an SD card. Therefore make sure everything is working with the wireless charging and that you insert a micro-SD card if you want extra storage. Preferably load the SD card with your toddlers favourite cartoons or other educational material (I added a bunch of space photos), the bigger the card the better, but you will still/always be able to alter the contents via the USB connection.

First get the USB micro connector (male) and 3.5mm audio jack connector (male), see below.

• 

  USB and stereo jack before Sugru application

Wrap them in cling film (plastic wrap) and insert them into the tablet, see below. Again the idea is that you can remove these after you apply Sugru to the whole tablet.

USB and stereo jack in tablet before Sugru application

Now it’s time to apply Sugru to the whole tablet, in preparation I taped a piece of card to the front of the screen (and left the original screen protecting plastic it came with) so that I didn’t have to worry about getting Sugru on it.  I also added a small bit of card over the speaker Sugru so that I could make a small Sugru bridge over it, essentially leaving a hole at the side for the sound to get out. It is best to do this process in two runs, first do the front and let it cure, then the back, this allows you to create a ridge on the front that stick both outwards and upwards, this will protect the screen from drops. Then apply Sugru to the back (this allows you to rest the device on the other side without deforming the Sugru as it cures, alternatively you could just support it using the screen). Once the Sugru had cured the USB connector and stereo jack were removed and a blade was used to widen the holes and carve away portions of the Sugru to allow access to the buttons (taking note of their positions beforehand is important). With the blade slowly remove layers of Sugru until the buttons react to pressing, you shouldn’t need to expose the button itself. It should look something like the images below.

Finished Back View with Strap

Finished Front view

Finished Back View with Wireless Charger

Finished Left View

Finished Back View

You will notice the small yellow spots of Sugru where the USB and stereo jack go. The holes left from removing the connectors after the Sugru had cured were widened slightly, then as before cling film was used to cover the hole, the connectors were pushed through and the yellow Sugru was applied, once cured you are left with the connectors seen below.

USB and Stereo Jack inserts after Sugru application

This seals those connectors when in use. You will have to remove the stereo jack if you want to listen to sounds, so I made a slight hole  in a Sugru “foot” pad where it could be kept when not in use, see below.

Stereo jack holder

I think if I was to do this again I might use a2small pieces of fishing line attached to the paper-clip loop before the Sugru was applied and attached these to the 2 connectors. This would stop them from getting lost, but the issue with this approach is that it makes it easier for the toddler to pull them out themselves. If you could somehow seal the fishing line under the Sugru it would be ideal.

Now all that is left to do is customise the tablet for your toddler, load up games and educational apps (the android market has plenty of free apps), and enjoy!

Happy hacking!

The post Toddler-proofing an Android tablet – wireless charging (inductive) and ruggedisation appeared first on Jake Rowan Byrne.

The main components are:

• Arduino (or other AVR-MK2 programmer)
• Web-server (I used a Raspberry pi, but any computer will work if it’s running Apache and PHP)
• Lego (if you want to make a Raspberry pi case)

Okay, first step is to program the AT Mega 8 chip.

I don’t have a AVR-MK2 programmer like [befinitiv], but I do have a number of Arduino boards. There are a number of ways to program an AT Mega 8 with an Arduino, but the most successful method I have found is to  use mega-isp code for Arduino.  A very good tutorial can be found at [blog.ntsd.net].  Upload mega-isp onto your Arduino.

mega-isp: programming an atmega8 with arduino from [blog.ntsd.net]

If you would like to program the chip before you have soldered it all together, follow the instructions above. If you have the hardware already assembled use the programming cable (purple, grey, white, black)  that sticks out the of the remote control at the end of the first tutorial (see image below).

In this case the purple is reset (Arduino pin 10), grey  (Arduino pin 13), white  (Arduino pin 12), black  (Arduino pin 11).

Using a Linux machine with avrdude installed run the following command in the terminal

$ avrdude -p atmega8 -c avrisp -P /dev/ttyUSB0 -b 19200 -U lfuse:w:0xe4:m -U hfuse:w:0xda:m

This is a combination of the standard setup for mega-isp and setting the fuses as done by [befinitiv]. The ttyUSB0 in the code above is the Arduino, so this may need to be changed, but if you unplug all USB peripherals and plug in the Arduino first it should be ttyUSB0.

• Plug in the remote control and hook up to the Arduino as mentioned above.
• Now download the code from my gitHub repository.
• Navigate to the folder “remote_controlled_socket” in the terminal.
• Run make.
• Now run make program

The code above largely builds on the code provided by [befinitiv], but adds extra support for up to 15 devices and adds channel selection to the mix.

Okay, now we have the remote all set up it’s time to set up the web based control. Essentially what we need here is a basic web server running PHP. Place the files from the “SerialPowerControl-web” folder on the server. As I’m running a Linux server so I have to alter the dialout group settings to allow the PHP script to communicate over the USB.

$ sudo pico /etc/group

-> add “,www-data” to end of dialout:x:***  (without quotes)

Now I’m using a Raspberry Pi as my server (as it’s a really cheap, low power and tiny computer) and I encountered a slight problem as the Apache server isn’t configured properly, to resolve the issue you need to do the following:

$ sudo groupadd www-data

$ sudo usermod -a -G www-data www-data

$ apt-get install php5-common libapache2-mod-php5 php5-cli
after installation, then restart Apache:
$ sudo service apache2 restart

If eveything is successful you should end up with the interface as shown below (point the browser to the server location of the power scripts) and once the remote is plugged into the servers USB port (make sure it’s the first USB device plugged in, so that it becomes ttyUSB0). This was easily thrown together using PHP and the jQtouch library meaning it will work in any Webkit Browser (Chrome, Safari, iOS and Android), it still works in Firefox, but loses it’s visual appeal.

Feel free to edit the scripts on the server so that the text reflects your own set up. You can add more devices (up to 15 per channel), events or change the default channel (the check boxes at the bottom of the image above, there are 32 possible channels). Check out the README file that comes with the scripts for the mapping of device numbers and the settings on the sockets (4-bit code). Let me know in the comments how you get along, the changes you make, or the issues you encounter.

I think one of the next steps is to try and add manual control to the sockets, there is no switch on the socket itself. You can of course use the wall socket switch if available, but this completely disables the remote feature. I also have one socket circuit embedded in the light switch for the main room lights, again the actual switch will turn off the lights but also disables the remote feature. So the new feature will have to allow for manual control without disabling the remote feature.

Bonus!

You can use the power.php and the GET method to use direct links to activate devices or profiles. Say for example I wanted to turn on device 1 on channel 4 (dip switch 4 down)

http://server-IP/power.php?p=1&c=11101

similarly for events

http://server-IP/power.php?e=leave&c=11101

Extra Bonus!

Making a case for your Raspberry Pi out of Lego. I got the inspiration from a bunch of scouts that have a post on the Raspberry Pi blog. I spent an evening going through my old Lego collection in my attic, collecting the necessary pieces.

Notice the clear blocks to let the power and Ethernet indicator LEDs light through.

To make your own I’ve included images of all sides, but essentially the Raspberry Pi is 7 x 11 in Lego dimensions, making the case 9 x 13.

Bottom

Top

Video and Audio Outputs

USB and LAN ports

Power and SD ports

HDMI

The post Adding web connectivity (via USB ) to remote controlled sockets – Part 2 (software) appeared first on Jake Rowan Byrne.

It essentially builds upon this blog  by [befinitiv]

Radio controlled sockets are a great way to save power in your home. Devices consuming more power on standby than the sockets do can easily be switched off with a remote. For example my desk lamp from a swedish furniture store consumes 10x more power (in the off state) than a radio controlled socket.

Even if the sockets consume more power in standby than the attached electronic device, they offer the luxury of turning stuff off and on without even moving. In short: They are really handy.

However, if you’ve installed the sockets, one sentence will often reoccur: Where the f*** is my remote?

The goal of this post is to show you a way of adding USB support to remote controlled sockets. This opens up a whole new world to remote controlled sockets. Plug this kind of remote into a computer and you can do amazing things.

This gives a pretty good justification for doing this, plus I wanted a worthwhile project to learn a little about programming standalone AT Megas (most of my experience has been with Arduino and PicAxe  to date). The main difference here is that I thought I could improve on the system by adding a Web UI to the mix (now I can control it from any device that has a web browser) and that I use a slightly different model of remote.

The main components are:

• Energy Efficient Remote Control Mains Socket Set
• AT Mega 8
• Nokia CA-42 Data Cable (cheap ones here)
• Arduino (or other AVR-MK2 programmer)
• Web-server (I used a Raspberry pi, but any computer will work if it’s running Apache and PHP)
• Lego (if you want to make a Raspberry pi case)

So you may (or not) have noticed that I have ordered different sockets to those used by [befinitiv] in his guide, the reason for this is that I live in Ireland and the sockets he was using have a European connection. When I opened the remote I noticed that the encoder used was different to the one in  [befinitiv]‘s  guide (SC5262 chip datasheet), my heart sank a little. Thankfully I found the datasheet for the HX2262 (datasheet) and it turns out to be identical, so crisis averted!

As [befinitiv] mentions the CA-42 Cable is used because it contains a serial to USB chip. I was happy to pick a few of these cables cheap from Meritline, but after opening them up I found that they were missing the power line (3 core rather than 4), so I swapped out that cable for a 4 core cable, I then found that the voltage on the on the other end was not as high as would be expected (about 3.2v rather than closer to 5v), this low voltage wouldn’t keep the atmega8 powered.  I figured it might be the traces on the PCB were so small they were creating extra resistance. Once I bypassed the PCB traces and went directly from the cable to the USB plug all was fine (see below). You can also see that the TX is hooked up to the green cable and the RX (not really used in this guide) is hooked up to the white cable.

Once that’s sorted it’s time to start wiring things up. There are differences in which pins are used on[befinitiv]‘s remote and the ones that I acquired , but after some testing, the relevant pins were identified. It’s handy to have the ATMEGA8 datasheet. So starting with the  ATMEGA8 start wiring it up as you see below (I decided to go with some vero board rather than ‘dead bug’ it like [befinitiv]). Don’t solder  the USB up just yet, we will wait until last as you will want to feed the cable through a whole in the casing before you solder it to the chip.  Note the purple, grey, white and black cable coming from the bottom, this is the cable we will use to program the chip.

Then on the front of the remote board (see below) remove the 5 SMD (surface mount device) components highlighted red and connect up teh wires as shown (the green highlights show no connection on this side).

Similarly on the back of the remote board remove the DIP switch (the big red block in the first images) and wire it up as shown.

Now to fit it all back into the case. Using a pliers snap away the casing that surrounds the buttons (see below). It seemed to come off rather cleanly for me.

Then make a  hole (drill or melt) in the casing to pass the USB cable through, make a small knot in the USB cable to put around the small post in the casing (see below) in order to stop any tension on the cable damaging any of your connection, then solder up the USB connection to the ATMEGA8. You can see here the complete assembly before we put it back in the casing (again note the programming cable at the bottom).

So now close it up and it should look something like this…

Now we are ready to start programming… See Part 2

Bonus picture, in case you thought it was a tidy process all the way through

The post Adding web connectivity (via USB) to remote controlled sockets – Part 1 (hardware) appeared first on Jake Rowan Byrne.

 Making Tracks

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