Daredevil Robot Direction Module (DRDM) Senior Design II Final Presentation

DRDM Team Kyle Inman Computer Engineer Module Design Website Software Design Russell Green Electrical Engineer Design prototype Research PCB Layout and Design Dr. Robert Reese Team Advisor Mukul Deshpande Computer Engineer Design prototype Website Serial Interface

Outline Problem Solution DRDM System Overview Constraints o Technical o Practical Testing Packaging Questions

Problem and Solution

Problem Currently, hobbyists and small robotics developers only have access to single direction range finding devices that require the user to perform timing calculations and manipulate trigger signals themselves.

Solution The DRDM will detect obstacles in four directions and transmit proximity and distance information to the user over a serial bus. o User interaction is strictly command based, no trigger pulses required. o All timing and distance calculations are performed for the user. o The module will have three configurable measurement modes.

What is the DRDM? The DRDM is an ultrasonic range finding sensor module that will typically be used by a robot or other device that must move and navigate obstacles. This device will be easily mounted and stackable to fit a variety of platforms.

System Overview -The user will command the DRDM over a serial interface. -A microprocessor will fire the sensors and time the return signals. -The distance data will be transmitted back to the user. User DRDM Sensor(s) Microprocessor

Design Constraints

Technical Constraints TypeDescription RangeThe DRDM must detect obstacles up to 2 meters away and as close as 10 centimeters. Field of VisionThe DRDM must be able to detect obstacles in 4 directions. Power Requirements The DRDM must operate on 5V power source. Communication Interface The DRDM must support three types of serial interfaces: SPI, I2C, and UART. Update FrequencyThe DRDM must be able to provide an updated mapping within 180 ms.

Practical Constraints Manufacturability The DRDM must satisfy the following dimensions: o Width: 4.1 in. o Height: approx 3 in. The DRDM must also be stackable and mountable in a variety of configurations. o Keeps the device small enough to fit almost any platform. o Versatile integration options.

Practical Constraints Sustainability The DRDM must have a modular design that uses commercially available interchangeable parts. o If a portion of the robot malfunctions, it can be replaced inexpensively and the DRDM can continue to function. - Example: one sensor malfunction would not affect the remaining three. o Want the DRDM to be as maintenance free as possible by using a simple software solution that can be easily updated through a USB connection.

Testing

Testing Procedures ●Verify the control transistor switch can turn the MAX232 on and off. ●Verify that the MAX232 is functioning and can amplify our input signal properly ●Verify that the transmitting transducer is sending a pulse. ●Verify that the op-amps are powered temporarily while the MAX232 is off. ●Verify that the comparator output will signal that a return pulse has been received. ●Verify the serial interfaces work properly. ●Test the complete function of the sensor with our master and slave software. ○Test if all the four sensors work. ○Test the different modes of operation.

Max232 Output

Opamp A Output

Comparator Output Time to return: 8500 us Distance: m

Serial Interfaces I2C

Serial Interfaces UART

Serial Interfaces SPI

Software Test

Notes on Distance ●This final version of the DRDM can detect distances from 10 cm up to 2.5 m. ●The same sensor design can be used to detect a variety of distances by “tuning” it differently. ○Small objects from 1 cm to 50 cm. ○Objects from 1.5 m to over 4 m. ●Different distance sensing options could be provided instead of offering only one distance range.

Packaging

Baseboard PCB

Sensor PCB (populated)

First Packaging Option Naked PCB

First Packaging Option Naked PCB

First Packaging Option Naked PCB ●The DRDM is not restricted to being used in a square configuration. ●Individual sensors can be removed and connected with wires to be mounted in any formation.

Second Packaging Option Enclosed

Second Packaging Option Enclosed

Bill of Materials MaterialsDescriptionAmount 3D PrinterUsed to create the enclosure for the DRDM $ SoftwareEagle and AutoCad$ PCB ManufacturingAdvanced Circuits will be the primary manufacturer for our PCB Designs $ ResistorsFor PCB construction$10.00 CapacitorsFor PCB construction$15.00 TransistorsFor PCB construction$1.00 Op-AmpsFor PCB construction$5.00 ComparatorFor PCB construction$3.00

Bill of Materials (cont.) MaterialsDescriptionAmount DiodesFor PCB Construction$2.50 Max232For PCB construction$18.50 Header PinsFor PCB construction (includes right angle & straight headers) $11.00 PIC24For PCB construction$5.50 TransducersFor PCB construction$34.50 Voltage RegulatorFor PCB construction$1.50 Pushbutton SwitchFor PCB construction$0.75 LEDFor PCB construction$0.50 Total PriceTotal of all components of project $ (excluding 3D printing & software)

References [1] Ultrasonic vs InfraredUltrasonic vs Infrared [2] R.Reese, B.Jones, and J.W.Bruce. Microcontrollers: From Assembly Language to C Using the PIC24 Family. Boston, MA: Course Technology, [3] J. Bryant. Using Op Amps as Comparators. Norwood, MA, Online: [4] Daredevil image by Declan Shalvey: [5] Novedge: kV7AodMVYA6g [6] Cadsoft Eagle.

Questions?