TV Watching Safety Distance Enforcer Dr Abdelhafid Bouhraoua

TV Watching Safety Distance Enforcer Dr. Abdelhafid Bouhraoua Mr. Kamel Chenaoua

Outline • • Aim of the Project Principle of Operation The Components Implementation Issues Competition Perspective

Aim of the Project To provide a way that prevent children from watching TV from a close distance to safeguard their eyes health

Principle of Operation From ANT To TV Distance Monitoring Device

How Does it Work From ANT To TV • Distance Measuring Device Continuously Monitors Distance to closest Object (Body) in Range • If Object Detected: Turn Off Antenna Input Distance Monitoring Device

Components • Distance measuring sensors • Electrically controlled On/Off switch • Microcontroller with communication means to interface the sensors

Distance Sensors - infrared From Sharp Electronics: Many ranges and two interface types: • Digital – Parallel or Serial Interface • Analog

Distance Sensors - infrared • Maximum range is 130 cm for the sensor with the analog interface • Inaccurate measurements above 80 cm. • Fragile devices not meant for industrial quality. • Digital sensors did not respond to datasheet specifications and could not be used • Analog sensors were properly interfaced

Distance Sensors - Ultrasound From Devantech: Acquired one device from a family of three: • SRF-08 Range Finder: – Standard two wire I 2 C Interface – Senses Objects up to 6 meters – 15 m. A current max

Distance Sensors - Summary • Ultrasound SRF-08 sensor was used in the prototype – Advantages • Robust, reliable product • Large range – Disatvantages • Price (around $40) • Marketing ultrasound in pet environments • Infrared Sensors – Advantages: • Price ($5 to $15) – Disatvantages • Fixed distance measuring (On/Off) • Unreliable

On/Off Switch Either a: • Relay • Transistor (MOSFET) Used a Relay for simplicity of interfacing

Microcontroller Rabbit Semiconductor Ltd. : Offers a wide range of Microcontroller cores: Acquired the RCM 3700

Microcontroller RCM 3700 features • 512 K SRAM • 512 K Flash • Ethernet for Networked Applications including web-enabled embedded apps. • Many standard interfaces: – USART, SPI, I 2 C, SCI, Parallel Ports • Many Timers for clock generation and PWM • Provided Development Environment • Standard ANSI-C language programming environment • Many libraries spanning as wide as: – PWM, SPI, USART, GPS, Timer Control, TCP/IP, etc …

Implementation A PCB board was designed and fabricated. PCB Schematic below: D 1 7805 C 1 C 2 C 3 Ra bbit Int erf ace R 1 +5 V GND SCL SDA RC LC Ant enn a Inp ut LED 1 R 2 +5 V GND SCL SDA Relay 1 T 1 Ant enn a Out put SR F 08 Int erf ace

Problems and Issues • Space problem • Test and Lab Equipment Shortage • Dong Jr. was a Great help. No Technician support after he left • Component acquisition problem • Reimbursement turnaround time • Student lack of interest • Lack of publicity for the program – Suggestion: Creation of web page for the innovation projects

Competition Taiwanese Company has designed a similar product and is shipping it (link below). Chinese Patent Pending http: //tech. monstersandcritics. com/news/articl e_1075388. php/Taiwan_firm_invents_gadget _to_stop_kids_from_sitting_too_close_to_TV Proves that we are on the RIGHT TRACK

Perspective • Cost reduce the product further – Replace Rabbit core by PIC microcontroller or similar cost microcontroller • Add keypad and display for programming sensor cut-off distance • Using a High-Frequency MOSFET as switch. • Competition proposed price is $450 • Our Cost can be reduced to around $70