I am a big fun of TV series! Mainly I like Sitcoms and Sci-Fi genders but due to time constrains I am unable to watch everything I want! Yes, day jobs these days almost consume our entire day.
But sometimes I am able to steal a little bit of time enjoying a few episodes of the good ones! And one of those was the first season of HBO Silicon Valley. I was so excited about this one even from the first couple of episodes. And I decided to tweet about it:
HBO respond back and few days later and couple of days after that I was having a shipping notice! I was so happy having on my hands some swags from the show! A t-shirt and a poster! Nothing special but a nice gesture for a fun!
Why this long intro? Well, I am an engineer, a maker in general, that wants to build stuffs. And the swags above came in a nice cardboard tube. A very strong, thick, with a nice light plastic type coating (helping with the moisture during shipping).
This makes a good indoor enclosure, but with proper treatment will be a nice fit for an outdoor enclosure as well. I am going to put a Raspberry Pi inside it together with a camera and some sensors for reading environmental variables.
The RPi is the Model B and has some connectors around it that I am not going to use. Those are taking space and placing the Pi slightly offset of what I want. I decided to remove them and use some of those in future projects. Nothing is going to the trash bin! Anyway, I am not going to use this Pi to somewhere else. The project will be placed permanently in my “lab” and I will do only software improvements.
I’ve stared with the 2.5mm jack and the AV output connectors
(The plastic silicon tube at the tip of the suction pump is a heat resistive one. You can find them in hobby stores and makes the pump works at least an order of magnitude better)
And then its time for the double input USB socket
By adding a little new solder on top of the already available one, I am able to desolder everything easily. A hand operated vacuum pump used to suck everything. The soldering iron and the 60/40 solder left so many residues. Using some clean alcohol in a paper towel removes everything.
It looks clean as new! Pay attention not to force the pins out of their vias if you do something like that. Those ones in particular, are really thin and delicate. You can easily destroy them without even noticing it!
Next in the line is the WiFi module. I will use an old Alfa card from a realy old penetration-testing project. The external plastic enclosure was already broken from the day I received it from overseas. I’ve removed the mini-USB connector from this PCB as well.
As before, same techniques used here as well for cleaning the pads. And same attention not to lift and PCB lines/pads too.
I will replace the previously removed USB connector from the Raspberry Pi with a super cheap double row pin header. I’ve cut this in length and bend slightly the two inner pins as the USB connectors (or at least the one used on the RPi) hasn’t got same pitch from pin to pin.
The placement is vertically as it works best for my needs. You can find right angle connectors as well if you want to do something similar
And here is how it looks after the desoldering, cleaning and then soldering process. Like you just removed it from its box. Like is was designed to be like that!
At the Alfa card side I’ve used ribbon cable with direct connection to the micro USB pads. You can find those cables easily on multiple online stores (and possibly to your local hardware store as well). They come in different colors, wire positions, pitch, flexibility levels etc.
I don’t have the best for the job but this one will work just fine with some bends!
And now after this pre-build its time to move on the tube side. From the shipping process the ends of the tube has some tear and dirt but the inside looks good. The plastic cups at the ends are in perfect condition and I will end up using both of them
Without the side connectors of Raspberry Pi, the board fits perfectly level inside the tube. I haven’t decide yet about how much length from the actual tube my project will take and that’s why I am placing everything on the inside to figure out (and visualise better) the best solution. On my mind looks something like the draw on the paper. And because you don’t have so many hands available to keep everything in place, some blue tac will do the job – securing the PCBs in place.
Before I start cutting the tube I’ve placed a little bit of black electricians tape around the one end. This will make a stronger connection for the plastic cups and will prevent the further tear of the tube
It looks like the 15cm are a perfect length for my project. Using a pencil I’ve marked the cut point
In order to cut a tube perfectly by using only one small point you have to use paper as well. Just place it around the circle and align it nicely.
Then using a hobby paper knife (preferably with a brand new blade) cut slowly the tube around the paper. Take your time with it! No reasons to hurry! And if you are careful enough the result will be excellent!
Again, a few rounds of electricians tape will do the job just fine adding strength at the ends
Its time for the cups! On the one side I will place the 2.5GHz external WiFi antenna and on the bottom side I will include a cut for a servo together with a place for an IO connector (a plastic RJ45). I’ve marked the center and use a drill bit to open the hole. The plastic is very soft and the drill cuts it like butter!
Then for the bottom cup, I’ve marked the position of the servo and then using the paper knife I’ve cut the plastic from the inside of the markings
The servo fits nicely!
The servo horn glued using few drops of CA glue on the bottom surface of the pan and tilt mechanism. In order to have a good bond with this glue remember to sand the smooth surfaces and then clean them with some alcohol. You can find this pan-tilt mechanism on the HobbyKing website. There is also a bigger size here as well. Its very durable and super cheap!
An already made pigtail with RG178 cable used for the external antenna connection. I know that isn’t a good idea to leave the original SMA connector in place but I was unable to remove it. Of course it will work fine, but “destroys” so many signal line theory laws!
A little bit hot glue on the ribbon cable joint for more durability and the WiFi card is in place inside the shipping tube!
I’ve also add the plastic RJ45 connector on the bottom cup. This will act as IO and power port. I was thinking of using something even smaller about that but the RJ45 connectors are cheap and easy to use. On top of that I was having a few of them around the “lab” from a previous project of mine
A small cut will handle the flex cable of the camera and the servo lead as well
A few quick notes on a paper to figure out the pin position functionality and then some soldering for making connections between the RPi and the WiFi as well as the external connector
The internals are almost ready! Now I will do a wire harness for external powering the RPi and making connection with the sensor module. An old Ethernet cable from a modem/router will be used. Its almost 1.5m long but I don’t want anything that big. That’s why I cut it way smaller
I’ve used some of the wires for power and some others for the sensor communication
A quick connection and voltage check with the multimeter to verify that everything is normal and then the external power! I was creating and compiling the code before and everything operates as it should be!
Now, a little bit more hot glue to secure everything in place. Some more wire harnesses for the servo cables (together with the power control) and voila!!!
Camera is ready, the servos are moving as it should be and the sensor is gathering temperature and humidity data! The data are forming nice graphical representations on the Exosite portal (you can use other web sides as well like Xively, Sense etc). There is also a web server powered by Apache that I can log in locally and watch the live camera feed (updating every 5s) together with the environmental data.
For the sensor I am using the newly made SHT10 Module! It carries probably the best Temp/Humid sensor in this form factor and is from Sensirion! The module can be powered and communicate properly from 3V up to 6V without any problem. This makes it a perfect candidate for multiple projects!
And here are everything in place! Working and looking awesome, especially if you consider that this is made from a shipping tube that normally will end up on a trash can. And the best of all… I can for sure use the same tube, two or maybe three times more!
More photos os the project here
For a setup with more sensors and more readable variables have a look for the Sensor Stick module.
For any other info, question, to say hello or anything else… send me a mail or drop a comment bellow!