1. ceLEDsTIal positioning
Team:
Stijn Wielandt
Steven De Lausnay
Advising Professor:
Lieven De Strycker

2. Navigation a

3. 3000 years ago…

5. Today

7. Why? GPS: doesn’t work indoor RF-localization:
Complex & expensive installation
Crowded RF spectrum
Restrictions (e.g., hospitals)
Poor performance
IR / Ultra-sound:
Good performance
Invasive installations of dedicated hardware

8. Visible Light Communication
Information is transmitted to users by modulating light intensity
CDMA: every LED gets a unique code
Why?
Dense distribution of light fixtures
Continuous lighting is already present
Low cost hardware at the transmitter side
Combines both illumination and communication …
1 bit/sec
10 bits/sec
1000 bits/sec

9. Visible Light Positioning System

10. LED drivers

11. LED drivers 700 mA with OOK-modulated data @ 16.384 kbps
CSD88539ND: Dual MOSFET
LM3421: LED controller with PWM input
MSP430G2302: microcontroller
LM : Voltage regulator

12. LED driver power supplies

13. LED driver power supplies
85 VAC - 265 VAC to 12 VDC flyback converter with active rectification
UCC28740: 3 A flyback controller
TPS71550: 5 V power supply for rectifier controller
UCC24610: Green rectifier controller
TL431A: precision shunt regulator
CSD19531Q5A: rectifying MOSFET

14. LED driver power supplies
85 VAC - 265 VAC to 12 VDC flyback converter with active rectification
UCC28740
TPS71550
UCC24610
TL431A
CSD19531Q5A

15. Transmitters

16. Transmitters d

17. Receiver boosterpack

18. Receiver Boosterpack
Converts the optical power back into an electrical signal
OPA2846: Dual OPAMP (low noise)
Trans-Impedance Amplifier
Ambient light filter
LMH6682: Dual OPAMP for amplification and filtering
TPS60403: 5 V negative power supply

19. Receiver Boosterpack
Converts the optical power back into an electrical signal
OPA2846
LMH6682
TPS60403

20. Receiver

21. Receiver
EK-TM4C1294XL Tiva C Series Launchpad for data sampling and communication with the PC
Receiver boosterpack
3D-printed lens mount

22. Visible Light Positioning System

23. Visible Light Positioning System

24. ceLEDsTIal positioning
Independent transmitters
Power supply + LED driver with control logic
Boosterpack receiver
Combination of analog filters and amplifiers
Compatible with the TIVA C launchpad
Results
Position errors of 6.5 to 20.6 cm in a test configuration
Luminous efficacy of 79 lm/W
Only Texas Instruments ICs: 12 different pcs

27. LED there be light and you can navigate