Week 4:

Date: 2/3/2017
Total hours: 12
Description of design efforts:
Testing a reverse-biased LED circuit with Michael Baio during the beginning of the week. The circuit was attached to an op-amp and was interacting with blue light. Unfortunately, the circuit did not produce a significant voltage difference, so the group has decided to proceed with IR leds. During the middle of the week, an h-bridge was developed to help drive the series of motors on the party pong table. Using 4 NPN transistors, the h-brdige was created and tested on the motor that was purchased in the previous week. The same day, parts were ordered from Texas Instruments, including a few micronctrollers, h-bridge chips, op-amps, and a timer. The h-bridge IC was used to replace the circuit I created. The circuit worked perfectly, and the microcontroller can now sufficiently control the DC motors. At the end of the week, the PCB layout was starting to be developed and will be followed up next week.

Week 5:

Date: 2/3/2017
Total hours: 15
Description of design efforts:

Started working on the pcb design for the microcontroller. Looked up design schematics for the TI msp432 and routed all the components needed for the design. This included the h-bridges, IR emitter and collectors, 3V 5V and 12V rails, and the caps/resistors for support.

During the middle of the week, I started to work on the layout of the design. All of the nets have been placed and routed. I had to work on both layers of the pcb; the final deisgn turned out to be more intricated than expected.

At the end of the week, the final pcb is almost complete. All the components are placed, the only things missing are a few support capacitors and the connection to the ATX power supply. The 20 pin motehrboard connector will probaly be used on the pcb, since it provides 12V, 5V, and 3V rails.

On Saturday, the party pong table will begin to be constructed at Charles' house.

Week 6:

Date: 2/17/2017
Total hours: 18
Description of design efforts:

On Saturday, the entire team went to Charles' house to constuct the party pong table. Over the span of 7 hours, we measured, cut, and screwed the entire table together using the miter and table saws. The border of the table is created with 2 by 6s (wood), and plywood is used for the top layers. The table is also modular, letting us easily take-apart and transport the table when needed.

Throughout the week, I finished entire PCB design, and checked over design with Mike. Submitted an order on Easyeda for our pcb, the pcb layout should be here in 4-5 days.

At the end of the week, I built a prototype for the cup/motor mechanism. The prototype is not finished yet, but pictures will be uploaded when a working prototype is completed.

Week 7:

Date: 2/24/2017
Total hours: 12
Description of design efforts:

This week I focused on hardware design and the pcb. The group had concerns that the motors we purchased would not have enough torque to lift the cups with water inside them. I designed a prototype that would be extremely close to the final design of the cup mechanism. This consisted of platform with the IR sensors, LED strip, and gear rail inside. The wires would run down the gear rail and be attached to the microcontroller at the base of the plywood. Dowel rods would also support the platform when it was raised and lowered, and make sure that the platform stayed on a straight path up and down. This also helped to prevent the motor gear from slipping from the gear rail. After the prototype was finished, it seems to work well. The doubts concerning the torque of the motors are gone and we beleive the group can proceed on building the final design next week.

On thursday, the ordered PCBs came in. Mike and I worked with Joe on soldering the microcontroller to the pcb, and then afterwards I started to solder all of the resistors, headers, caps, mosfets, and other components onto the pcb. Some mounting headers for the h-bridges need to be ordered next monday, but the pcb should be ready to be tested soon, as well as shown during the midterm presentation. One concern of the pcb is in regards to power. Hopefully the traces on the pcb are large enough to withstand the current required to drive the motors, around 1.5A for each motor. Although all of the motors will not be driven at the same time, I am still a little concerned about the traces. More testing will be done next week.

At the end of the week, I built a prototype for the cup/motor mechanism. The prototype is not finished yet, but pictures will be uploaded when a working prototype is completed.

Week 8:

Date: 3/03/2017
Total hours: 5
Description of design efforts:

This week I wasn't able to put as much time into the project as I would've wanted, due to other academic commitments and the midterm presentation. I prepared for the presentation and wrote the slides for the schmeatics and pcb. The schematics had to be updated a little bit to be cleaner for the presentation. Also, I helped Mike and Charles debug the LED strip issue that we experienced this week. More of the strips were burning out, but we think the issue is due to the PI not being able to provide a consistent form of current for the entire LED matrix. More testing will be done next week. Finally, tomorrow (saturday), I Will solder the JTAG header onto the pcb and start testing the different modules and componenets one by one.

>

Week 9:

Date: 3/10/2017
Total hours: 10
Description of design efforts:

This week was a very successful week for myself and the team. The previous week and this week, we were trying to solder the components onto the pcb and test if we coudl program the microcontroller correctly. Unfortunately, the micro was not functioning during the beginning of the week. After applying 3.3V on the pcb to power the micro, the PSU instantly went to 0.5V and was shorting the board. To compensate for this issue, I soldering 2 more microcontrolers on different pcbs and tested those. The other pcbs contained the same issue. However, after discusing with Yang, it was discovered that the problem was a small solder bridge on the pcb. After removing the solder bridge, the board no longer shorted and we were able to program the micro through the JTAG connector. After this step, Mike and I tested a few components on the pcb including the h-bridges, IR emitter/collectors, and the analog LEDs. We also tested some of the logic in Mike's code, including when to raise and lower the cups. So far, everything has been working as expected and we were able to confirm that the pcb is working, and that the code is working so far. This week, we will attempt to solder the rest of the components and start building the frame around the LED strips. The picture below is an example of GPIO toggle that worked correctly on our pcb after flashing through the JTAG connector.

>

Week 11:

Date: 3/24/2017
Total hours: 10
Description of design efforts:

This week is the start of the final stretch of the semester. We had some problems with the LED matrix and it was hard to diagnose the problem. The strips would intermittenly work if the connecting wires were held in specific orientations, and only about half the strips would work at a single time. With help from Joe and Yang, we realized that the issue was coming from the wires. After replacing the wires, the LED matrix started working perfectly, and we are starting to make designs on the LEDs (such as Purdue's logo). I have started to build the grid that will encase the LED matrix and prevent it from getting danaged. Using MDF wood, we will cut out a "tic-tac-toe" type of grid that will sit on top of the LED matrix. On top of the grid, a plexiglass frame will be positioned. I hope to finish this on Saturday or early next week. The only major components that need to be finished are the 20 motor platforms and the LED matrix.

>

Week 12:

Date: 3/31/2017
Total hours: 15
Description of design efforts:

At the beginning of the week, Mike and I finished designing the final motor configuration. Earlier in the semetsr we tested a design consisted of a gear rail and a simple DC motor, but this did not provide enough torque. We ended up deciding on a pulley system using a low RPM/high torque motor. We tested the configuration on Tuesday and it worked flawlessly. All we have to do is wait for the other 19 motors before we can start assembling the final design. On Wednesday and Thursday, I designed and developed the PCB for the final breakout board on the raspberry PI. This PCB contains 12 push button headers for the different reracking options, 4 neutral buttons for start, NRST, and other functions, as well as 3.3V, 5V, and 12V headers that can be ran to the microcontrollers on either side of the table. It also contains headers for the LED matrix, which consists of 5V headers and an output data line. I made the schematics and board layout for the entire design on 2 days, and we submitted the design to be fabricated. It should be here early next week. This PCB was not as difficult as the microncontroller PCB, but it still entailed a lot of individual components and parts. Next week will hopefully be a solid week to put all of the components together.

>

Week 13:

Date: 4/08/2017
Total hours: 12
Description of design efforts:

Almost all of the components are ready to come together. This week, the rest of the PVC guides for the platforms were cut and constructed. After cutting the 20 PVC guides, the next step was to make the individual platforms for raising/lowering cup mechanism. This took the majority of my time; each platform contains an IR emitter, IR sensor, 12V analog LED strip, and a central dowel rod. Each platform took an average 20/30 min to complete with most of the time coming from soldering the different wires and making sure all of the components are labeled. By the end of the week, 6 of the platforms were created. Over the course of the next week, more of these platforms will be created. I also worked on some small issues with the PCB. During the middle of the week one of the wires shorted from the ATX PSU. This might have damaged the board, but it still seems to function alright. The only issue seems to be that the microcontroller is drawing a lot more current than before (0.1A now, before was around 0.003A). I talked to Joe about this issue and he doesn't think it warrents a replacement of the microcontroller since everything still seems to work. However, if we see issues in the future, we will definitely replace the microcontroller. The first picture is a "work-in-progress" image of my work on the table, and the 2nd picture is a picture of all of the components needed for the platforms, and the amount of time it took to make each platform.

>

Week 14:

Date: 4/14/2017
Total hours: 15
Description of design efforts:

This week, I continued creating the platforms, and finally finished them by the end of the week. All 20 platforms are done, and we are currently building the final mechanisms to raise and lower the cups. I also fixed a few minor PCB issues, including the need to include resistors between the micro and h-bridges. We noticed that the motors were spinning randomly due to interference between the micro and the h-bridges even when the micro was sending the "off" signal. The LED grid will be completed tomorrow (saturday), and hopefully we can get an entire side of the table working by Monday. We are also trying to find the most efficient way to consolidate all of our wires, as shown in the 2nd and 3rd pictures. That mass of wires represents all of the connections between the PI, micro, and the CPLD. Hopefully we will find a more efficienty way to hide all the cables and route them more efficiently.

>

Week 15:

Date: 4/21/2017
Total hours: 20
Description of design efforts:

After some deliberation, the team has decided to remove the motors from the project. During the past few weeks, we've been running into issues whenever the motors are conencted. Even with the fuses and the arc suppressors, the microcontroller and the PSU have been acting strangely. For example, the PSU would suddenly shut off when the motors were connected but not even running, and we've burned through 2 PCBs when the motors were connected. Furthermore, the wiring and connecting of the motors would require even more space on a platform that is already crowded with wires, as shown in the pictures from last week. So instead, the platforms will stay in the up position, and instead of re-racking automatically, the user will be able to remove the cup manually. This week, I worked on more wiring and connections on the blue side of the table. I also started wiring the red side of the table, connecting all the components into the 5V, 12V, and GND rails. We've also been debugging a lot of issues between the raspberry pi, microcontroller, and CPLD. The raspberry pi is able to correctly calculate the scores on each side of the table, and the microcontroller is able to correctly trigger the CPLD whenever a ball enters the cup and is scored. By this weekend, the blue side should be completed and the red side should be halfway completed. The project will hopefully be done in time for the spark challenge.

>

Week 16:

Date: 5/3/2017
Total hours: 25
Description of design efforts:

We finally finished the project this week! This week consisted of many different steps to finish everything. I helped wire up the rest of the wires to the pcb and raspberry pi on the red side of the table, as well as painting the entire table. I also helped to build and assemble the LED matrix wood grid that was placed on top of it, and I also worked on soldering a few componetns that broke during this week (led strip, few platforms). After the week was over, we presented our project at the Spark Challenge and won 2nd place at the competition! A lot of high school and propsective students were very interested in our table, probably since it was flashy and had RGB lights on it. We explained to them the different aspects of the table, and how each different component worked. It seemed like everyone enjoyed the project, a lot of people took pictures of our table as they passed us. Also, the judges seemed very interested in our project, and asked us if we had any plans for the future of the design. Unfortunately, we all live in different states so it would be difficult to transport the project and work together on future designs. Overall, I had a lot of fun this semester creating this project, and I learned a lot concerning creating our own designs.

>