1. Electronic Engineering Final Year Project Switched-Controlled Turntable Name: Dean McDonnell Supervisor: Dr. Maeve Duffy

2. Electronic Engineering Final Year Project Objective of Project 1.To Design and Build a Switch-Controlled Turntable 2.Controlled through an infra-red remote control 3.Full 360 degree turn, bi-directionally 4.Stepped in 90 degree angles 5.Addition to project includes a second motor 6.Design Issues: Fit under assortment of beds and Portability

3. Electronic Engineering Final Year Project Previous Design Another version designed and built in the USA Two students from University at Chapel Hill Use by children with severe and profound disabilities at Lake Wood Elementary School Children were unable to retrieve toys independently They could not choose between items when presented multiple options Table required auditory, visual and tactile feedback Needed to fit the needs of a variety of children Named “The Lazy Susan”

4. Building of Previous Design Electronic Engineering Final Year Project

5. Previous Design Advantages were immediately noticed Allows access to multiple toys from a single location Consists of partitions used to segregate the toys from one another LED’s and spoken messages are also integrated Provide visual stimulation and auditory feedback Very important for teachers, therapists and children Electronic Engineering Final Year Project

6. Operation of Previous Design Electronic Engineering Final Year Project

7. Initial Step Infra-Red Execution Infra-Red Receiver Microprocessor Motor Drive Motor Table

8. Finding the Motor Stepper Motors were a must Datasheets of different motors researched Tests carried out on different motors Results had to show that motor is capable of rotating a mass of 5 kilograms Also needed to be cost effective Rotate the mass within approx. 7 seconds without exceeding 12 volts Minimal stopping and starting times Electronic Engineering Final Year Project

9. Testing the Motor Initial test involved having no load Select few motors were advanced to second test Second test involved load of 5kg Load tied onto coupling that was placed on motor Results achieved determined the appropriate motor Chosen Motor was the MFA COMO DRILLS 919D SERIES Single Ratio Gearbox Electronic Engineering Final Year Project

10. Motor Test Results Electronic Engineering Final Year Project

11. Finding the Motor Controller Electronic Engineering Final Year Project H-bridge was chosen for the task Used to control the polarity of the motor Used to turn the motor bi- directionally Also used to “brake” the motor

12. Testing the Motor Controller Electronic Engineering Final Year Project The controller placed into the breadboard. Voltage supply added Motor attached to breadboard Motor turned bi-directionally as well as “braking” when needed Oscilloscope was used to observe wave patterns

13. H-bridge Characteristics Electronic Engineering Final Year Project L293 used for this project Two separate sides - Only one side needed Pin1 – Switch Enable Pin2 – High Pulse (Oscilloscope Channel 1 Connected) Pin3 – High Output to Motor (Oscilloscope Channel 2 Connected) Pin4 – Ground Also Connected to Pulse Ground Pin5 – Ground Pin6 – Low Output to Motor Pin7 – Low Pulse Pin8 – Voltage In (Connected to Pin16)

14. Motor Controller Results Electronic Engineering Final Year Project Shows the stepping changes on the H-bridge

15. Testing the Microcontroller Electronic Engineering Final Year Project 8051 ADuC831 used for this project A program is needed in order to test the 8051 Programmed in C After weeks of testing, the program finally resulted in direct communication between the computer and the 8051

16. Microcontroller Results Electronic Engineering Final Year Project Direct communication between the computer and the 8051 LED flashing indicates this Hyper-terminal reads in the character ‘1’ from the 8051 (seen in next slide)

17. Microcontroller Results Electronic Engineering Final Year Project

18. Addition to Microcontroller Results Electronic Engineering Final Year Project Addition to the program has been achieved This addition involves the motion of the motor through the H-bridge The motor can be controlled to turn clockwise as well as anti-clockwise The motor can also be stopped or “braked” by the H-bridge

19. Next Steps Electronic Engineering Final Year Project Next steps are based around the infra red user device This involves the building of the infra-red receiver After that, the project will lead on to getting the second motor This second motor will control the upwards/downwards motion of the table Once this motor is coded, the physical designing of the table will follow

20. Questions? Electronic Engineering Final Year Project