2016年3月17日星期四

Bench inspection

The Group Project: Bidirectional Visitor Counter using ARM Microcontroller  

This week we experienced the bench inspection and our project was assessed by both our tutor and assessor. Frankly, it was an successful test of our device, and both IR system and Laser system performed well during the inspection. The figure below is the final version of of our achievement. 


After the assessment, we took a group photo as a memory of this experience. 

In conclusion, this is an excellent experience of a teamwork, not only have we learnt some professional knowledge about circuiting design and elements utilization, but also we could work in a team and cooperate making our work more efficient. 

2016年3月5日星期六

Week 5 of Group Project

The Group Project: Bidirectional Visitor Counter using ARM Microcontroller  

Last week we programmed the code to baed on ARM controlling the comparator controlling circuit which is the last one of the three modules as planned in the first week. For the final week, we combined the three parts and assembled them. Below are the figures of the emitter and receiver connection. Once there is an object between them it will prevent the receiver obtaining the signal.




However, it is not stable of the emitter and receiver pair to work between a long distance. So it can not not be used as a commercial product. This can be a mini product for testing. The figure below shows how the IR is woring


We have also designed a complementary circuit using laser and photo-resistor whose basic theory is the same with IR pairs. Based on the characteristic of the laser, the  photo-resistor is able to receive the light from a long distance which can meet the demand for counting visitors at the entrance.  Below is the connection and the resistors lie on the left and lasers are on the right.


We also tested it, the figure below shows how it is working.


However, the disadvantage of laser is that it is not power efficient and it will consume more power compared with IR receivers. 

In the final, we combined both IR and laser. Below is the completed design. 

The video link below shows how our project with IR detector system works.

https://youtu.be/SUbmmv-X6pc