I´ve been working on my final project, and trying to find an adequate sensor technology for it. My project is about creating a desk work space / surface for the home, that will incorporate some proposals to deal with:
1. Wireless, induction based recharge of devices to reduce cables.
2. An interactive responsive device based on tracking.
On the first proposal, there exist induction recharging solutions. They are simple emmiter and receiver induction coils that can be used to power different devices such as lamps, cel phone chargers, speakers and other low voltage products. Starting from an existing basic recharging kit from Adafruit, I want to add it a proximity or close range prescence sensor. I´ll probably go for the tiny active / passive ultrasonic sonar device shown on the last class.
This is in order to bring some degree of interaction to this simple device; I.e: a sensor that can “feel” the presence of the device to be recharged over the receiving coil, so It can activate a switch which powers the emmiting coil on.
Update 01:
On the second proposal, I want to explore the possibility of sensing and tracking to bring interaction to a desktop product. I´m very interested into the cool possibilities the Pixy CMUcam5 camera could give, due to its high degree of color and shape discrimination. I´d like to connect that camera to a microcontroller and put the camera on a servo mount, which in turn can orient a cooling fan, a web camera or other device that needs tracking to better interact with the user.
This camera works with hue and saturation values for color recognition instead of RGB, whiche gives sensing ability even on rooms or places with different light intensities.
This input device can be mounted onto a modified pan – tilt base. Both camera and servo wires are connected to an Arduino Leonardo, (Currently for test and learning only. Later on will be mounted on a lab made Fabduino.)
Below are some exploration sketches of possible ideas for a device that uses shape and color sensing combined with tracking to be used in an interactive desktop object:
Update 02:
The idea of using the Pixy CAM was dropped since the sensor is mounted on its own proprietary board, plus microcontroller and its own color and shape recognition (complex.) software, which goes against was required for this assignment. (to make my own input sensor.) So In any case, I´ll use the nice PixyCam as a complementary device.
Going back to a sensor that can detect the prescence of a device, I opted to change the active sonar sensor for a passive photo – transistor sensor. This decision was mede because the sonar sensor is bulky and difficult to make a discrete device hidden on the desk / table, and the photo – transistor, in addition to be far smaller, works on a finer / smaller scale than the sonar. Because of mill availability, I´ve opted for a laser + acid etched board. It´s ugliness will be hidden by an enclosure in the final project.
After loading the bootloader with the ISP, I´ve loaded the program made in C with the FTDI. :
This program was made in C, with the help of this book, and a debugger I´ve found on the internet here:
The code can be found here:
To test the sensor, I´ve downloaded TeraTerm, a free download virtual terminal software, which enabled me to establish serial communication with the sensor. It verifies the sensor is working by opening a window with a horizontally scrolling stream of ASCII symbols. If the light intesity is constant, the same ASCII symbol is shown, is the photosensor window is gradually obstructed, the symbols change gradually until is completely dark. See picture and video:
Video:
SensorTest03 from Patricio Ortiz on Vimeo.