Tag Archives: Week 12

Testing & Feedback (Week 12)

What Happened?

Our 7-segment, 3-digit screen came in this week! Our group scrambled to add it to our board in the hour of class we had before prototype testing began. To assemble our counter using the clicker, we were using a combination of instructables, professor/FabLab advice, and our own tinkering. We were able to get a few segments of the display to light up, but the code we had was originally written for a 1-digit display. This caused one segment of each of the three digits to light up, but no one digit had a full set of segments filled in.

We explained our problem to the first group who analyzed our prototype. We also explained what we hoped to make the counter into – a fully functioning, light-sensitive and compact product that can be mounted on the door frames of local businesses. They gave us some good ideas about overall business ideas and how we should present the finalized product, but we still needed to fix the segment display and transition to the PIR sensors before we could apply any of their recommendations.

When the next group audited our prototype, Norman offered a ton of advice on how to connect the sensors, remove the mess of wires we have, and get the board to work with a new setup. He and his team are working on the planter that senses light and soil moisture and are also using an Arduino and 3-digit counter. Norman is someone who tinkers around with this tech a lot and has a knack for finding his own solutions – he helped us learn how to move away from the instructables and start to find our own solutions!

Why does it matter?

At first, I didn’t think having other groups prototype our product would be effective until we got all the code and wires working. However, the session was very helpful in refining our business ideas and what we will do to improve the product after we get it working. Also, we would have never gotten the help from Norman and his group if we hadn’t has this session! So thanks to both groups and especially to Norman for all of your help.

What are our next steps?

We will move forward with the light sensors – no more push button for us! Now, we need to modify the code to count up and down. We will do this by programming sensor 1 to count up if something passes in front of it, and sensor 2 to count down if something passes in front of it. This can be done with simple “if” statements in the Arduino code.

If we have enough time, we will look into placing the external memory on top of our Arduino, allowing the users to remove the SD card at the end of the work day and download all of that historical data.

Then, we will print a simple case for the system to cover the exposed wires and make the counter easier to attach to the door frame of a business.

Here is a video of our prototype. 

Building & Testing (Week 12)

Hello, everyone!

This week, my group focused on building our working prototype and uploading our code to the Arduino board. We spent past weeks learning what the laser sensors were, how the Arduino worked, and really getting an idea of how the more complicated pieces in our people counter operate. However, when we started to put the first working model together, we found that we had missed learning about some of the little things! Is there a positive and negative end to the LEDs? Can we connect resistors to each other? Can we put the resistors directly on the Arduino or do we need to put them on the perf-board? Does it matter?!

We learned that it’s important not to overlook these little things, but we were able to figure them out as we went. We did not have a 470 ohm resistor (called for in our guide), so we connected 2 resitors of lessor values to get to that 470 ohms. Here is the website we used to learn how to determine how much resistance one resistor has. If you didn’t know, ohm resistors use colored bands to show the user what resistance they carry. You read the bands left to right – each color has a number attached to it. Below is a chart you can look at o determine what resistance your resistor might have.

Since our 7-digit display had not yet arrived,  we made our first working prototype with individual LEDs. A 7-digit display is just many LEDs put together in a particular oder. Organization of the lights aside, connecting a few LEDs to our perf board allowed us to get a similar effect.

We were able to upload our code to the Arduino and connect all the wires we needed to. We did not have a battery on hand, but we used the Arduino connector in conjunction with a 5V cell phone converter and plugged the counter into the wall socket. Regular sockets run at about 120V, so it was important to have the converter in order to not overload our creation.

We were able to hook up the counter to power and run the program – we made a few of the LEDs blink! We are currently using the push button, not the laser sensors, so every time I pushed the button, we’d have a light blink. It was gratifying to see all our wire connecting and learnings pay off.

Another thing my group discussed was memory. An Arduino can hold the memory of the program its running, but needs extra memory to hold anything else. If we want our counter to hold historical data, we have to add a chip or another board to our Arduino. This will require us to solder some wires, so we will look more into this next week. I found this forum online discussing Arduino memory that has been helpful to me. It might also be helpful to groups also using Arduinos.