Niket Sheth Chris Karman Erik Scherbenske Peter van der Hoop BoneCrusher Automation Floor Art Super Transcriber (F.A.S.T)

Build a robot to reproduce shapes, text or follow user input paths. Robot will use markers to create drawings on the floor. Scalable drawings depending on floor size.

Tethered Control using: Joystick Keyboard Pre-Encoded Instructions Touchpad Wireless control should eventually replace tethered line

Milestone 1 Moving robot that can be controlled with directional inputs via USB input Milestone 2 Robot can reproduce shapes and text given a user input. Expo++ Robot is wireless, can use multiple marker colors, has collision and boundary detection sensors, and can follow touch pad input drawings.

Input CPU (MSP430) Motor Drivers (L297, L298A) Sensors Marker

Robot moves with two Sure Step stepper motors that take inputs from DRV8412 motor drivers The DRV8412 is a high performance integrated dual full bridge motor driver Takes 4 out-of-phase inputs to drive the motors We have switched from the DRV8412 to the L298N and L297 L297 generates 4 outputs from a single clock input to drive the motors (connected to L298N)

Operating Supply Voltage up to 50V 3A max current output Operating frequency up to 500kHz Integrated self-protection circuits (under voltage, over temperature, overload, short circuit) No external schottky diodes required Takes four off-phase step functions as input

Much simpler two phase bipolar stepper motor driver than the DRV8412 Takes only one step input 46V, 4A max Over temperature protection High noise immunity

MSP430

NEMA degrees per full step Half-Step Capability Holding current up to 1.7 A Input 4 out-of-phase step functions 1.6 ohms

Use a stepper motor to rotate markers into place (PWM). MSP430 provides the path to draw Multiple color control through the motor PWM.

Controls rotation of marker wheel Spring controlled pressure on markers Color change capabilities Uses the same motor drivers and stepper motors as the wheels Rotate Pen Down/Up Motor

MSP430f PWMs Multiple digital I/O UART Control DAC 8 MHz

5V Rail Reset Button Motor 1 PWM Motor 2 PWM Motor 3 PWM Motor 1 Enable Motor 2 Enable Motor 3 Enable Motor 1 Direction Motor 2 Direction Motor 3 Direction PC Connection Motor Reset Collision Detection

Motor Control 3 PWMs (Square Waves) – 3 Motors Speed – Period of waves Distance – Duration of signal Marker Control Controlled by Marker Wheel attached with Stepper Motor Signal will enable the wheel to rotate until marker in DOWN position.

Opto-isolators Separate the MSP430 from L298N and L297 in case of mishaps. May need to add transistors for current boosts. MSP430 might not be able to apply enough current to the opto-isolators Control of the Direction and Speed will be determined by code on MSP430

UserKeyboard InputJoystick Input Path Generated Input Basic Directions PWM for Each Wheel Generated Marker Position Selected Stop From Collision Sensors Trackpad Input

Collision Detection Bumpers that detect collision and send data to CPU Infrared that detect objects in path before collision Boundary Detection Detect predefined physical boundary Infrared (black line surrounding “canvas”) Using MAX3100, MAX3120 infrared drivers. Software boundary Max distance allowed for travel from initial starting point Turn OFF or correct motion when the sensors detects a problem.

3 to 5.5V operating voltage. 1 CM to 1 M detection range. High accuracy (built-in narrow band pass filter). Compatible with MAX3100 (IR to UART Data Link). Schmitt Trigger input/output operation.

Power Control Board Provide 50V for the stepper motor, 7V for the logic circuitry (motor driver), and 2V for the MSP430 CPU chip. Isolation circuit using opto-isolators MAX232IN for providing current to motor. Power monitoring and reporting controlled by MSP430. Conservation of power by shutting down components not being used by controlling the signal to the enable pin in the motor driver. Rechargeable battery.

TaskPeterErikNiketChris Mechanical Chassis/MountsX Electrical Input ControlsX Motor ControlsXX CPU/Power Management XXXX Marker/SensorsXX Software CPUXX UI SoftwareXX IntegrationXXXX ManufacturingXX TestingXXXX DocumentationXXXX

ItemQuantityPrice ($)Purchased? Mechanical Chassis/Mounts Material1 X 1 m75 Castor Wheels24yes Differential Wheels210 Stepper Motors (Sure step)340yes Other Mechanical Parts (Screws, Springs, Servos)-50 Electrical LEDs10 Battery/Circuitry/Controller-150partially Battery Charger125 Infrared Sensors (LED, Photo Diodes, MAX3100, MAX3120)8180 Bump Sensors105 Microcontrollers (MSP430F1232IPW)/USB interface-50partially Motor Drivers (TB6560AHQ, DRV8412, L297, L298, L6210)-50yes PCB Printing-130 Other Electronic Parts (Wires, Connectors,etc)-80partially Miscellaneous Markers 5 Presentation/Documentation(Printing, Poster, Binding) 65 Total 929

Signal/Power Noise Opto-Isolators, separate regulators purchased Motor Accuracy Loose Contacts between wheel and ground – Slowly build up the speed to avoid loose contact. Inaccurate stepping by motor – High current keeps steps accurate Power management surges and spikes Opto-Isolators Lose communication with robot Range - Software controlled Power OFF Loose wiring – Effective Build Up Uncertainty in learning curve Uncertainty in parts availability and delivery Unfamiliar technology