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For the electronic proof of principle the 555 timer circuit was constructed in Multisim. The circuit worked as needed to modulate the IR LED: with 70 cycles on, 10 cycles off at 38kHz. This was acheived using two astable multivibrators as seen below. The next step is to build the 555 timer, which is currently a work in progress. For the electronic proof of principle the 555 timer circuit was constructed in Multisim. The circuit worked as needed to modulate the IR LED: with 70 cycles on, 10 cycles off at 38kHz. This was acheived using two astable multivibrators as seen below. The next step is to build the 555 timer, which is currently a work in progress.
The logic for the microcontroller program was worked out, and the registers needed to accomplish this were found. It was proven that the program we hope to use to transmit the appropriate data from the LEDs to the computer can be accomplished using the PIC16F877. The next step is to use the logic and registers to program the microcontroller.    The logic for the microcontroller program was worked out, and the registers needed to accomplish this were found. It was proven that the program we hope to use to transmit the appropriate data from the LEDs to the computer can be accomplished using the PIC16F877. The next step is to use the logic and registers to program the microcontroller.   
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{{:group1:modulator_printscreen.jpg|}} {{:group1:modulator_printscreen.jpg|}}
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 +Week 10: Nov 3-7
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 +Our electronic proof of principle should have been observed for this week, as we not only completed and successfully tested the modulator circuit, but also were able to output text that was received by the microcontroller. Both of those components are coming along quite well, and all we have left is to build the physical structure of our completed system, and program the algorithm into the microcontroller. A problem with the original IR receivers existed in that the signal would not be able to recover itself after it was lost, however this problem was remedied when we used a new type of receiver that was given to us from Glen. The IR signals are focused onto the receiver with a lens, and are able to maintain the signal quite strongly. The microcontroller is being utilized for its timers, however an external oscillator was needed to be added to it as there is no on-board clock. Further programming will be done this week, as well as an updated budget to determine where we stand cost-wise.
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 +Week 11: Nov 10-14
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 +The microcontroller programming is the only aspect left to accomplish. We have completed the modulator circuit and are able to power it using batteries, while also focusing the signal on the receiver with a lens. We must now understand how to use "interrupt flags" and how to trigger them with our varying signal. Further research will be done in the upcoming week on how to approach this problem and integrate our desired algorithm.
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 +Week 12: Nov 14-21
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 +It was found that the microcontroller does not have the capability to take in three squarewave inputs and determine when they are blocked, as well as determin object velocity. There are not enough timers (4 are required and the PIC 16F877 only has 3), and the algorithm contains too many interrupts so that they interrupt each other and make the operation inefficient. The solution to this has been to use a comparator IC after the receivers so that when the signal is not blocked the signal is high (+5V) and when the signal is blocked the signal falls low (0V). The microcontroller program to match this new receiver output has been written and successfully compiled. Tomorrow the whole system will be tested in the lab, including the programmed microcontroller and the new comparator circuit. The mounting materials will be bought and assembled tomorrow afternoon. 
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 +Week 13: Nov 24-28
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 +The entire project was demonstrated this week. The analog components worked fine. The Microcontroller proved to be much more difficult to program, and the the demonstration showed the MCU creating an output of the word "Person" numerous times for every person that walked by. However, it was able to be programmed to account for direction and distinguish between a person, a car, and a cyclist. There was a major setback as one of the receivers had burned out, so now the project must function using only two instead of three. For next week, we must provide better functionality of the Traffic System circuit, to just observe pedestrian traffic using two beams.
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 +Week 14: December 2
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 +Today was the second chance for demonstration for our group. After countless hours in the lab and spending time there into the late hours of the morning, we were able to fix the algorithm for the microcontroller to take two times; one for the crossing of each beam, and compute the speed of a passing individual by dividing the distance between the beams by the time difference. This concept was proven, however a small problem occurred with the rollover of the timer on the microcontroller - some instances the time would be off and there would be an incorrect speed given. However it was demonstrated to work succuessfully for numerous trials. Perhaps changing the distance to minimize rollover time would have helped, however the functionality of the circuit today was impeccable. The output to the screen displayed:
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 +Time 1: xxxxx
 +Time 2: yyyyy
 +Speed: zzzzzz
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 +Where x, y, and z were given numbers.
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 +The speed demonstrated direction as crossing the beams from one side produced a positive speed, and crossing from the other produced a negative speed. Also data logging was programmed to occur. All in all, the final design - both hardware and software - were done quite well and there was a great effort put in by both parties. This class was a great hands on learning experience, and the given project was very interesting to work with. Expect the coming reports to have further in depth details about the components and testing of the Traffic Monitoring System circuit.
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 +Thank you,
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 +Leigh Conroy and
 +Mike Cino

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