Laser based projector

This is again a final year project by Melissa and her team, who all are students at Cornell University. The electrical part of the project consists of Galvanometer and the microcontroller which acts as an input to the position detector sensor and also are responsible for control loops which have been implemented using proportionate derivative controller. The mechanical part consists of a combination of different devices which makes up the laser projector. A part of the software runs on a Linux based PC which handles file parsing, point scanning, frame display, and serial transmission to the control board.

For this laser projector, the moving and still parts of the galvo are switched around. The current running through the coils causes the rotary motion of the magnet, and subsequently, both the position detector electrode and the mirror attached to the ends. The project have been designed keeping in mind that further research and development should take place on a similar concept. The project schematics needs a little bit of improvement as accessing the board is a challenging task. A different project but still a long way to go before we see something like this in the market.

Autonomous Goalie

This project will definitely be liked by people who loves playing air hockey. In short term, it’s a low cost robot which detects a puck coming towards it and moves in its required direction to stop it. The great point of the project is, it’s highly responsive and doesn’t use any robotic arms to stop the puck. The heart of the project, an ATMEGA 1284 MCU, takes in echo patterns from each of the sensors, interprets them and accordingly actuates the robots motors. Moreover, it requires negligible human input and can also be powered from a battery based source.

Due to multiple tasks running simultaneously, they have used a tiny real time kernel to execute task in a coordinated manner which has made the robot more responsive to the puck. In the final design, with all the sensors mounted on the robot, a threshold of about 34cm or 1 foot was observed to do the best job of detecting the puck and resulting in proper functioning of the robot. A low cost robot doing a job of the goalie in an very efficient way. However, since the puck is round in shape, there have been certain difficulties in picking it up due to echo not being reflected back.

Infrared based Mouse control

This project moves and clicks a mouse cursor on a computer screen by tracking where the user’s eye-movements using infrared eye-tracking technology and a gyroscope. It can be useful for people with physical disabilities and provide them with a way to control the monitor. Instead of using a camera they are using a combination of LED’s and phototransistors which have reduced the cost of the project by a huge margin. The LED’s used are mounted on a custom made spectacles like think, which doesn’t restrain user from making any movement and hence giving this device an edge over other products presently available.

infrared

All of these glasses-mounted components namely the LED system along with the gyroscope are connected to a microcontroller, which parses the LED and gyroscope data into USART packets and transmits it wirelessly. The packets are read by a wireless receiver on a separate ATMega1284P board, which moves the mouse cursor using a Java program based on the information received. The LED’s used are low power LED’s which also doesn’t damage the user eye. You can read more about this project on the project website.

Heart Rate monitor

This project by the undergraduate students of Cornell University allows you to measure your heart rate along with blood pressure through the use of optical based sensors. Their intention is to gather data for large-scale analysis for the automatic prediction of heart disease. The heart of the project is the ATMEGA 1284p, which is used to control the infrared LEDs that will transmit light which is reflected back to the light to frequency sensors.

heart

The microcontroller takes in the signals that reflect pulsatile measurements, and will digitally process these signals into pulse measurements, and send the data through either USB or bluetooth to a PC. The PC will have a GUI that graphically shows the two pulses and the blood pressure and pulse. The mouse unit contains the mouse controller, a mega1284P microcontroller, an ultrasonic sound transmitter, three ultrasonic sound receivers and an XBEE wireless transceiver. The base station contains a mega32 microcontroller and an XBEE wireless transceiver. A GUI has also been created to observe the data without any use of additional tools. The complete mathematics along with the schematics of the project can be found on the project website.