week18
Project Development
What is it?
My final project consist of three different interactive modules that can be assembled together to create one customized light fixture that can interact with its environment.
The user will be able to put together their own design installation depending on the functionality they desire. They can be installed as wall features or partitions, on columns, set up as a floor lamp; endless use just by assembling the different components together.
Every module will light up everytime its connected to another module by the use of stereo Jack connectors 2.5mm. It will also interact with the user through a capacitance sensor making them react to the touch.
How does it work?
The project is using both light and sense to create an interactive light experience.
Each module is 16.0 cm Long x 3.5 cm wide x 3.5 cm high which, after different tests of scale and proportions, was the best size to be easily manipulated for any kind of users.
It is a very user-friendly kit, easy to assemble and low in cost. This kit is made of a laser cutted sheet of polypropylene that can be folded to create the shape, 3d printed connection caps to receive the electronic board with the RGB LEDs.
I was able just to make one of the three modules due to the lack of time, but I managed to duplicated into 6 other modules to connect them together and to have the following design.
Procedure
Materials and prices
Laser cut
I started by 3D designing the modules in 3D and thinking about how I was going to make the shape keeping flexibility and transparency as well. Then I found the polypropylene plastic sheet that is nice and I decided to use it. So I had to find a way to assemble a 2D shape into a 3D shape and design the joints as well. I laser cut the polypropylene sheet of 0.5 cm thick and engrave a pattern to play with shadows and lights. This way, since my project is about multiplicity, I find it easier to create many modules by only using one sheet of plastic. It can fit around 8 modules on each sheet.
In rhino, once the 3d module is built, I had to add this command: "unroll surface" to flatten it and add joints.
Regarding the joints, other than liking the idea of the circles, I think it was a nice and clean way to use for this kind of thin materials. I had to do again so many test to have the perfect measurement and connection.
3d print
I used solidworks to design the 3d print caps to fit the plastic and to receive the boards with the hole in the middle, one to receive the jack female connector + board and the other one to receive the jack male connector.
I then exported the file as STL. to send it to Cura software to print using RepRap machine. I had to set the settings in Cura : bed heating to 50 and nozzle to 0.5
Electronics
My biggest concern was the connection between them and how are they going to respond one to another just by being connected. At the begining, I was thinking of using magnets for the connections but turned out to be not really practical specially with the electronics. Instead, I decided to use the Jack connectors. I started testing with my previous assignment of asynchronous with white LED and since I am using now jack connectors which only have 3 pins so I first tried to connect the VCC GND and Tx to see if I get the same result instead of the 4 pins, VCC, GND, Tx and Rx and it worked. But the difference was that the boards were not sending any messages to the serial port, just receiving.
Since I decided to use RGB LEDs to interact, I had to change the original board designed from Neil's Attiny 45 to attiny 44 so I can use more pins for the RGBs.
So each module contains 1 board with RGB LEDs and I managed to mill and solder 6 boards in total that will listen to a bus. A master board transmits on the bus, addressing each other board individually via a node ID. The master is responsible for interacting the other nodes with a capacitance sensor.
I had to redesign the whole schematic design adding the female jack connector to the board and in consequence change the c-code to adapt to the attiny 44.
Jack connector added to the board
The board will be fixed into the cap so I decided to solder the connectors onto the board but that wasn't an easy task as I did not have the schematic drawing of the jack female connector on Eagle so I had to make a custom footprint to add in eagle connecting it to VCC GND and Tx. 
Capacitance sensor
The bridge board is different than the nodes because I combined both step response board and the asynchronous bridge together on one board. So I had to redesign the board and the code by adding the Attiny 44 instead of 45. 
So the main module contains the bridge board, a copper sheet for the capacitance sensor to be able to send message to the other boards and respond by modulating light and interact just by the touch.
I have tried for many days to figure out how to rewrite the codes of Neil's so the stepresponse and the asynchronous work together.
First test
First I started to test the asynchronous board trying to communicate with the nodes and lighting up the RGBs in different colours in a loop sending numbers from the bridge to the other boards to see if they respond, wihout adding the sensor yet.
Here are the c code for the first test: C code Bridge without sensor and nodes
Second test
Once that was done, I tried adding the step response code "Hello.load.44.c" to the Asynchronous bridge code so the RGB LEDs will respond to the value that the sensor is receiving with same loop numbers, changing the colors to red once I touch the sensor
Here are the c codes: C code Bridge with sensor and nodes
Third test
For the third test, I tried to add a piece of vinyl copper on a propylene sheet to test the value and to see if it works perfectly. I have changed again the code and added a cycle of colors using the same idea of the loop. So once the sensor is touched, the nodes respond by creating a cycle of colors from one node to another.
Here are the c codes for the second test: C code Bridge with cycle sensor and nodes
Final
Finally, I fixed all the modules together and this is the result:I have added all the files needed in the following folder: general files