The last two weeks have been incredibly hectic in regard to our project. We launch this coming Saturday and we have all been double checking our payload to make sure it is launch ready. We were having a problem with one of our voltage regulators. It was reaching very dangerous temperatures. after replacing a regulator and a resistor, we were still having the same problem. Low and behold we were drawing too much power from the battery at once. We disconnected the camera from our main power source and wired it to its own battery. The problem instantly went away, like we anticipated.
The way sensors work is by recording a voltage in relation to what it is sensing. A big part of the job is actually being able to convert the recorded data into usable data. This past Monday, I tested the data of that was recorded from the majority of our sensors to make sure the data recorded was actually good. The calculations were good, and our sensors are recording actual data. This is going to be extremely helpful for the conference we are speaking at in a few weeks.
All of this hard work and this is what it translates to!!! HAHA
This week our team constructed the payload's enclosure. Creating a solid design was less challenging than expected.We wanted out payload to have angled edges so that the cameras will naturally be pointing in a downward position during the balloon's flight. We began with a few rough sketches on a white board and then went to Solid Works to build our design. Solid works enabled us to pre-build the payload and make sure our lengths and angles were correct before botching the real product. After we drew the enclosure we printed our design to full scale at a Staples. With our template being at the proper scale we were able to trace the design with an razor knife and fold the box up and finish the enclosure very quickly. Tomorrow we will fit all of our circuits in the payload enclosure and get ready for launch next weekend!
Below is an image of the 2D Solid Works payload we built. Next week will be full of super cool photos, so get ready!!!
This has been a very challenging week in regard to our balloon project. Last week we finished soldering out circuit board...The we wired an LED to it to tell us that everything is working if the light is on. When we went to download software onto the circuit board it kept giving us a communication error. And thus began the hours and hours of debugging. Our mentor professor couldn't figure out the problem, we couldn't figure out the problem, we didn't know what to do.
Finally on Monday after re-soldering potential bad connections and removing solder from where it shouldn't be, I had the idea to plug in and test other circuit boards to the computer. Every board failed. This finally told us that the problem wasn't out circuit board, but the connection to the computer. We brought out a laptop that wasn't connected to the school's network and VOILA! everything works!!!! Our diagnosis is that because of the schools network security the driver for the cable we were using was not being installed on the computer, making every effort to download software onto our circuit board a failure.
I wish we would have tested that sooner, but after this experience it was nice to know that we did everything right the first time. This week was not a very visually stimulating week, but here is a video all about the only comfort our group knew of for the past week..the LED
After successfully learning how to properly breadboard a circuit last week, it is finally time to start building my first circuit board. This week we etched and drilled our circuit board. To describe the images below: First we start with a blank copper circuit board with a layer of photoresist on it. A pattern is then placed over the board and exposed to a black light for a couple of minutes. After the board has been exposed, it is developed. The developer washes all of the photoresist off of the circuit board. From the developer, the circuit board is soaked in a bath of ferric chloride. The ferric chloride washes away all of the copper from the pattern that was burned into the circuit board in the beginning of this process. After all of the copper is washed away the circuit board is complete. Before soldering a circuit board, the painstaking process of drilling is next. 200+ holes were drilled into this board. In the final images you will notice some scratches on the circuit board. The copper didn't completely come off in a few places and was scratched off with a razor knife.
To start putting my knowledge of circuit design together I began breadboarding my first circuit this week. Like anything I do for the first time, it usually takes longer than expected. I think I ha to take my breadboard apart three different times, before I eventually nailed it. Breadboarding is a way of testing a circuit, before the circuit is etched or soldered together. In the early days, an actual breadboard or wooden slab was used for this process.
As you can see from the image, circuits are placed on the breadboard, and then are connected to each other in a very specific manner. A circuit diagram is my instruction manual for this.
I finally completed this yesterday, and today I will be testing it to see if it works. Fingers Crossed!
Our group decided what sensors we will be using this week. The payload will be taking pictures as well as live video to document the payloads journey to 100,000 ft and back down. We will also be observing elevation, temperature (inside and outside of the the payload), acceleration (will discuss this later in the post), particulate density as the payload reaches near space, pressure, atmospheric moisture, and possibly gamma radiation.
I have started to do some preliminary research to see how complicated it is to build a geiger counter type sensor. Luckily for me, there are lots of geeks in the world, and found countless technical schematics for building a sensor that will detect gamma rays over a given period of time.
The project I am doing this semester requires planning and preparation. Next week we will be ordering all of our sensors for this project, which means that this weekend the group has to figure out what we want to observe as our payload enters near space. Keeping in mind that we have certain voltage and power usage constraints to our system. Up to this point we have been learning a lot about the engineering design process. Today we learned about powering our system. Discussing how resistors and voltage regulators will be crucial to our payload design.
Monday our group will be sitting down and deciding what sensors our payload will use. We have a few limitations, but I think that this part of the process should go smoothly.
Last week we began designing payload enclosures. To test them we filled them with 1kg weights and threw them off of our balcony. Enjoy!
