The leds being used in this system are NOT IR leds. They are house hold led bulbs, which produce visible light(white, blue, red, yellow).
TRANSMITTER SECTION.
the transmitter will consist of an arduino uno, mosfets, 7led bulbs connected to seven different pins. Communication via led bulbs is basically through on off keying, first the data has to be converted to binary, and send to the pins, for every 1,the led will be on, and every zero the led will be off. Different messages will be transmitted by the leds.
Led - message being transmitted
LED 1 - A-1001(example of the binary after converting)
LED 2- B-1101
LED3- C-1110
LED 4- D-0011
LED 5- E-0101
LED 6- F-1100
LED 7- G-1111
these leds will be placed in different parts of the building,in all the rooms while others in the corridors, they won't be interconnected or aware of each other, each led will send its message repeatedly, very fast, the human eye won't even notice the flickering.
RECEIVER SECTION
the receiver section will consist of an android phone, hc06 Bluetooth module, arduino mega, emic tts, speaker, photodiode. When the module is switched on, it should query for a destination from the user, this will be achieved by sending the text "where do you want to go" to emic tts, which will convert it to speech and output it via the speaker. After a valid destination is provided via the Android phone through the Google speech app, which will then be sent to the hc 06 module mounted on the arduino board. (let's pause for little bit on the receiver)
DOWNLOAD THE SKETCH OF THE MODEL BUILDING.
Each message from each led invites a unique response from the receiver. The receiver should have like a library of some sort, when receives an A via the photodiode (while will convert light to voltage and the board will demodulate it back to 1&0s and back to the letters) it should send "move forward" to the EMIC tts. Let me make a table for the received signal and the response/text to be sent to the EMIC tts.
A-move forward
B-turn left
C-you are in the Lab
D-turn right
E. - you are in the dean's office
F-move forward
G-you are in the bathroom
So a combination of these responses should lead the user to a final destination. In this scenario there are only 3 final locations, the lab, deans office and bathroom. Am going to upload a room schematic so that you can understand better, to get to the deans office, the user (according to my model house) has to move forward, move forward, take a right, the s/he will arrive at the deans office. Since the leds A & B are next to each other, and B is not needed to guide the user to the deans office, the receiver after receiving the signal and realizing its a B, it WON'T send the message to the EMIC TTS, it will just send "move forward ". Using my model house, am going to make a table showing the final destination and which leds actually direct the user to the rooms ,message being transmitted is in the brackets.
LAB - LED 1(A),LED 2(B),LED 3(C)
DEAN'S OFFICE - LED 1(A),LED4(D),LED5(E)
BATHROOM - LED 1(A),LED6(F),LED7(G)
When the user is heading to the bathroom and receives from led 2,and led 4,it will prompt it to send move forward since their messages are not in the library of guiding the user to the bathroom.