Scrolling LED

Scrolling LED

Abstract

The objective of this project is to become familiar with the Dip Trace software, soldering components, and understanding manufacturing processes for constructing a PCB. Through the construction of a Scrolling LED, provided by Carl’s Electronics on hansenhobbies.com, I was able to become familiar with all the various parts of microelectronics assembly. First the components were measured using a caliper. Next, the schematic was constructed to mimic the schematic produced by Carl’s Electronics. After the schematic was complete, it was transformed into a PCB layout. Through the use of the auto-route function in Dip Trace all the components were connected. Once the PCB was manufactured, I successfully soldered all of the components onto the board, and it functioned exactly as it should.

Project Description

The project I decided to make was a Scrolling LED using 3 8x8 LED matrices. I found this project on hansenhobbies.com and chose this scrolling LED through Carl’s Electronics. The starter kit came with 42 components that needed to be soldered onto the received board, but our first step was to basically throw away the board we received.

Figure 1

Figure 1: Complete PCB for a Scrolling LED

Next, I measured each of the components received using a digital caliper, and insured that all of the dimensions were accurate for when I designed the layout of the board. Following these measurements, a schematic was constructed based on the schematic produced by Carl’s Electronics (Figure 2). Certain portions of the schematic provided by Carl’s Electronics were simplified, so it made it a bit more difficult to make an accurate schematic. By looking at the PCB they provided I was able to trace which leads went to which components. It was a painstaking process, but it was worth it when the LED’s worked after soldering all the components.

After the schematic was complete, I transferred the schematic layout to the PCB layout (Figure 3). I laid out all the components exactly where I wanted them on my PCB to reduce the amount of traces necessary for the board to function. To further save space, 3 components were soldered onto the back of the PCB. These 3 components were the shift regulators for the LED’s matrices.

Figure 2

Figure 2: Scrolling LED schematic from Dip Trace

Figure 3

Figure 3: Scrolling LED PCB layout from Dip Trace.

After all of the traces were routed and I made sure that everything was laid out exactly how I wanted, the various files were sent off to a PCB manufacturer. There, the PCB was created, and fortunately 2 copies of everyone’s PCB were made. I did not need both of my PCB’s but it is nice to have a clean copy of what I actually created (Figure 1) and a functioning copy with all the components attached (Figure 4,5).

Figure 4

Figure 4: The front of my Scrolling LED PCB with components attached.

Figure 5

Figure 5: The back of my Scrolling LED PCB with components attached.

As you can tell from figure 5, there was quite a bit of soldering necessary for my project, and a lot of the components were grouped together very closely. Initially, it was tough to solder some of the components to the board, but as I got used to using the solder iron it became very simple. I was able to finish soldering and cleaning the board after about 1 hour. Fortunately, my project worked after one try. I connected a 9V battery to the power supply input and immediately there was a message scrolling across the board! “Thank you for assembling me correctly! HansenHobbies.” The best part about this PCB is that there are 4 switches on the front that allow you to edit what the message scrolling across the PCB says. The key functions are fairly basic, and I was able to learn to edit the message in a matter of minutes. Currently, the message the LED’s display is, “Hi, my name is Michael and this is my Scrolling LED Project for IME/MATE 458. Thank You!! J.” It took about 3 minutes to program this sentence, and with practice this time could be reduced to about 1 minute.

Conclusion

Conclusion: Overall, I really enjoyed this class and project. I continue to show off this project to all of my friends and they are very impressed. I learned to use software unfamiliar to myself, Dip Trace, and even if I only know the basic steps, it is a great start. I am much more confident about talking to fellow colleagues about various components on PCB’s and how they are produced and function. I didn’t have the opportunity to debug my PCB because it worked after the first try. The majority of my work went into ensuring that each and every lead from each component was going to its appropriate counter part. By spending the majority of my time in the beginning steps, I saved a lot of time not having to fix any traces or components in my project. This type of work should be encouraged in the following years. Do good work in the beginning and the reward will be less work in the end!

Figure 6

Figure 6: A complete and functioning Scrolling LED created by Michael Turovskiy.

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