Tag Archives: LDR

Arduino, PIR Sensors and more! (Week 10)

Hello all!

Shapeways

This week, we had a guest speaker from Shapeways, a 3D printing service and marketplace company. She took us around the facility and showed us their printers and office space. You can print with anything from ceramic to precious metals! The link to the website is here. I will be attempting to design a necklace for my mom – I’ll post the results in the next blog!

Darwin's Silver Cladogram Tree 3d printed

Our Project

My group is making an Arduino/IR sensor that will count the number of people moving in and out of a building. Our idea is that this product will be a low-cost option for local restaurants, shops, and even places like homeless shelters to count how many customers are in their establishment at a time, as well as store that information and build up historical data that will be useful in predicting foot traffic and demand in the future.

This week, we took a full inventory of the parts Vishal and the FabLab have given us – we have almost everything we need! Believe it or not, our counter requires a lot of tiny senors, lasers, and other parts that are easy to lose (fingers crossed we can keep everything in one place). A large part of our meeting this week consisted of actually understanding what each of these parts do and where they will connect. I was able to teach my group members a few things I learned from my ECE course, but we still had a lot to look up! We are following a rough Instructables outline of the project which I’m infinitely grateful to have. Below are a few pictures of parts.

 

Above is a 7-segment display and a PIR sensor. The display will work just like that of a digital alarm clock – it will show the number of people present in the building at any time. The PIR sensor measures infrared radiation emitted from a field of view. This is what will “measure” how many people walk in and out. 

STMicroelectronics

Above we have a light dependent resistor (LDR) and a voltage regulator. The LDR has a variable resistance that will change when different lighting falls over it. The voltage regulator will allow us to maintain the proper voltage level when the product is up and running. We will be using a 9-volt battery to run the counter, so we need to make sure the electricity running through it is monitored. 

This is the main part of our project – the Arduino! This is what will make all the parts work. Arduino is an open-source hardware (& accompanying software) company which makes this little, single-board microprocessor you see above. In simple terms, you can code commands in a special software, connect this board to your computer, download the commands you’ve written onto it, then take the board and put it on any project you like! I’ve used it before to makes LEDs flicker and blink in specific patterns.  For our project, we will command it to count every time the lighting (detected by the PIRs and LDRs) changes.

These are not all the components of our project – just a few of the most interesting. I am trying to get some of the coding some this weekend, so we will see if it works next week!