New Human Computer Interfaces Amnon Dekel HUJI – CSE, Spring 2006 Class 5 May

New Human Computer Interfaces - HUJI - Spring On the Menu Group Exercise Review Serial Port: –Board2Board –Board2PC –PC2Board Some more sensors Changing the world: Actuators Projects

New Human Computer Interfaces - HUJI - Spring Exercise Review View the exercise projects Problems and Difficulties? What Have You Learned?

New Human Computer Interfaces - HUJI - Spring Serial Communications The OpenBoard can communicated with other devices in the world using the Serial Communications Protocol You can use this to have a board Send data to another board and receive data from another board. You can also use this to have the board communicate with a workstation (Why?)

New Human Computer Interfaces - HUJI - Spring Board to Board Call soft-serial-on once at the beginning of the program. Sending Values: –Sending is done from Pin C0. –the command: send1 value i.e. send1 100 Receiving Values: –You can receive on 4 ports: B0, B1, B2, B3 –To receive you need to do 2 things: check if a new value has been received on the pin. newin1? will check B0 (newin2? will check B1, newin3? will check B2, newin4? will check B3). The code: loop [ if newin1? [do something with in1] ] –Oren comments: to use in1 best to set it into a different variable, like: settemp in1 if temp = 100 [do something else]

New Human Computer Interfaces - HUJI - Spring Board to PC Use the regular programming cable configuration Sending to the PC: Use the send command (not send1). Anything sent this way will be sent to the PC serial port. send value Reading the data on the PC 1.Make sure the PC is in fact receiving the data. Use a terminal program for this (like Hyperterm) 2.If all is well- write a program (in Java, C, whatever you like) to read the serial port. Sending data to the Board from the PC: You use the following primitives in your code on the board: enable-recc (to enable receiving of serial data) recc? (check if a value is waiting in the serial buffer) recc (the value itself, so you can set into another variable) To send serial data to the board, use the send command from the programming environment. To send serial data from a different application on your PC, it should work just by sending numbers to the serial line, so enable the serial line and send an integer.

Some More About Sensors

New Human Computer Interfaces - HUJI - Spring Push buttonSlide switch Toggle switch Rocker switch Types of Input Switches

New Human Computer Interfaces - HUJI - Spring Sensitive Switches Hair trigger/whisker switch Roller switch Mercury/Tilt switch Magnetic/Reed switch

New Human Computer Interfaces - HUJI - Spring Analog Sensors Force Sensitive Resistor (FSR)Pressure sensors

New Human Computer Interfaces - HUJI - Spring Analog Sensors PhotocellTemperature Sensor/Thermistor

New Human Computer Interfaces - HUJI - Spring AccelerometersFlex Sensor And more … And more: Capacitance sensors Piezoelectric sensors More info: ITP Sensor Workshop ReportITP Sensor Workshop Report

Changing the World: Actuators

New Human Computer Interfaces - HUJI - Spring Examples

New Human Computer Interfaces - HUJI - Spring Actuators Pneumatic –Air Pressure causing movement Hydraulic –Liquid Pressure causing movement Electronic –Electro-magnetic movement Motors (Kinetic) Speakers (Audio) Lights (Visual) More Info

New Human Computer Interfaces - HUJI - Spring Linear vs. Rotary movement Torque Gear Motors

New Human Computer Interfaces - HUJI - Spring Speed (RPM) Movement – mechanics Controlling the Position Feedback about the position How much weight can it carry Torque How much power does it need Price Selecting a Motors

New Human Computer Interfaces - HUJI - Spring Speed (RPM) Movement – mechanics Controlling the Position Feedback about the position How much weight can it carry Torque How much power does it need Price Selecting a Motors 1. The moment of a force; the measure of a force's tendency to produce torsion and rotation about an axis, equal to the vector product of the radius vector from the axis of rotation to the point of application of the force and the force vector. 2. A turning or twisting force.

New Human Computer Interfaces - HUJI - Spring Types of Motors Stepper DC servo DC

New Human Computer Interfaces - HUJI - Spring DC Motor: Cheap. Very easy to connect Minimum control Turns 360 degrees. Can add components for more control: –Speed: change the voltage using a POT –Direction: change the polarity –Position: can’t!  Add an H-Bridge circuit Motors

New Human Computer Interfaces - HUJI - Spring DC Servo: Expensive Very easy to connect Includes all components Turns 90 degrees to each side Full control: –Speed: change the voltage –Position: Needs CHECKING Motors Waiting for answer from Oren

New Human Computer Interfaces - HUJI - Spring DC Servo - Controlling the position: They rotate 0 to 180 degrees depending on the pulsewidth. About 1.5 sec to move 180 degrees. The DC Servo takes a pulse of between 1-2 ms every 20 ms. A pulse of 1 ms will turn the motor to 0 degrees; 1.5 MS will turn to 90 degrees, 2 ms will turn it to 180 degrees To keep a servo in its current position pulse it with the same pulse width every ms to keep it there. Controlling a Servo

New Human Computer Interfaces - HUJI - Spring Stepper: Cheap Usually 12V Hard to connect Need extra components Turns 360 degrees. Can stay still in one position Full control: –Position –Speed Motors

New Human Computer Interfaces - HUJI - Spring We want to control a few elements: Speed Strength Direction Position Controlling Motors

New Human Computer Interfaces - HUJI - Spring We want to control a few elements: Speed  power Strength  Current Direction  current direction/Pulse Position  Pulse Controlling Motors

New Human Computer Interfaces - HUJI - Spring Controlling the position: Controlling Motors DC Motor Controller בקר (H-Bridge) Encoder BS1 משובFeedback PWM

New Human Computer Interfaces - HUJI - Spring Using PWM to control the position: For each motor we know the RPM: in X Volt, how many rounds per minute. From this info we can calculate how many degrees a pulse moves in a certain time. When accuracy is important inertia should be taken into account (and gear to balance it) Controlling Motors

New Human Computer Interfaces - HUJI - Spring Where to get motors? חנויות טיסנים חנויות רובוטיקה חנויות אלקטרוניקה

PAUSE What have we been dealing with so far?

New Human Computer Interfaces - HUJI - Spring Vision SOUND Analog INPUT Digital Input  Sensing the world Controlling the world  Digital Output Analog Output Computing Communications MOVEMENT (Motors) Output to the PC Controlling 220V world Movement Position Change Pressure Temperature Audio Video

New Human Computer Interfaces - HUJI - Spring Projects What’s a good project? Process Milestones Presentations

New Human Computer Interfaces - HUJI - Spring What’s a Good Project Explores interesting, and preferably, novel scenarios Shows interesting use of the technology Exhibits a working prototype for at least one main part of the scenario. Explains how it fits into the wider scenario. Includes good documentation –Project explanation, process, problems, code, possible improvements –Project Poster

New Human Computer Interfaces - HUJI - Spring Project If we have time: –Class Discussion of Projects Home Work: –Prepare a Project Proposal: Intro – What problem am I trying to solve Research (what exists…) Concept Technology Milestones (7 weeks)