One of the first projects we did to explore what we had learned on paper was to build our own oscilloscope. An oscilloscope measures voltage over time and provides a graphical display of that data. We were given kits bought from amazon that included the parts and board, but it was our job to solder the parts to the board and get it up and running. A google drive folder with all the pictures we took is linked above.

Planning:

Since all we had was a bag of resistors, capacitors, and a myriad of other little parts, our first order of business was to organize and label each part or group of parts. For example, there were eleven 0.1 µF capacitors, so we picked all eleven of them out of the pile of parts and put them under one piece of tape that we labelled 0.1 µF. Some parts were easy to distinguish what they were, but for others, we had to look closely at the lettering and numbering on the parts. For the resistors, instead of trying to use the color code to determine their values, we used a multimeter. On the multimeter, there is a setting that measures resistance, and it gave us a reading when we put one end of the multimeter on one end of the resistor and the other on the other end. After we meticulously checked off all the required parts, we were ready to start soldering.

Soldering:

We soldered the parts in the order in which they were listed on the user manual (see below). However, another logical way to solder the parts was to solder the innermost parts first and then work your way outwards. When you do it this way, the parts you have already solder don't get as much in the way. The leads of the parts should be pushed through from the side with the outline and print and soldered on the back (the side without any lines/letters/numbers).

Before assembling it all together, we had to review soldering techniques and desoldering techniques (for when we made a mistake). It was important that we achieved the "hershey kiss" shape around the leads and that the solder filled in the holes. This would become crucial as we would see when our oscilloscope would not turn on. When we were finally ready to solder, we taped down multiple parts at a time so that we didn't have to keep flipping over the board each time we soldered one part. It wasn't a bad idea at this this point to use the multimeter to check the resistance values of the resistors one last time before soldering them permanently to the board. To find where each part went, we looked on the manual, which to the left of the part number/value gave us a pair of a letter and number. This letter-number pair was printed on the board, indicating the location of each part. Once each part was soldered, we clipped the ends of the leads.

Setbacks and Challenges:

This project did come with its setbacks and challenges. One minor mistake we made was soldering the diodes backwards. Because they are polarized, they needed to be soldered with a certain orientation. The end with the silver line was the negative end. We also had a small issue with soldering one lead of a slide switch and melted the plastic around the hole. Luckily, it didn't cause any problems, but it could have if it had interfered with the connection. One major setback we faced was that our oscilloscope didn't initially turn on, and when we finally got it to turn on, it only showed a white screen. No graphical display appeared, signaling that we had a loose connection somewhere. Therefore, the only thing we could do was inspect each part closely using a magnifying lens and make sure we had soldered it well. We learned that not enough solder can be as bad as too much solder. Furthermore, under the magnifying glass, it was easier to see if the solder was just sitting above the hole, which in that case, we had to heat it and let it slide down into the hole. After some trial and error, it eventually turned on, the LED blinked, and the graphical display appeared. A picture and video of our working oscilloscope are posted below.