Today was our lazy Sunday, so we all slept in this morning. We met up with Jiao and Dian in the afternoon, and we rode our bikes over to the gym to play some ping pong. Dian brought along one of his classmates that was fairly experienced at playing ping pong. After our time ran out, we headed over the the badminton area to play a few games. At first we started playing a serious game, but we eventually started messing around playing our own way. Later we rode our bikes back to our apartments and spent the rest of the day browsing the internet and relaxing.

Today we decided to take a trip to the Wuhan Zoo. We met with Dian and Jiao in front of our apartment at 8:00am and made our way to the subway. Once we arrived at our destination, we took an uber the rest of the way. Since we were visiting on a Saturday, we were expecting to see a lot of people there. To our surprise the zoo was fairly empty, so we got to enjoy the zoo without the crowd. People most likely avoided coming because of the scorching heat, but we were determined to see the red pandas Dian and Jiao had told us about. The zoo is surrounded by a large lake filled with black and white geese, cranes, ducks, and other exotic birds I could not identify. As we walked along we came across a pond full with coy fish, and we payed a few yuans to get a chance to feed them. As soon as we dropped some food in the water, all of the coy fish swarmed to try and eat some food. The central part of the zoo contained wild animal exhibits, and we got to see a lot of different animal such as penguins, hippos, kangaroos, and of course the red pandas. Most of the animals we saw seemed sluggish probably because of the weather; they most likely they despised the heat just as much as we did. Afterwards we went to a nearby mall and had lunch at a traditional japanese restaurant before returning back to the university.

Today we returned to the lab to continue work on our HUST project. With the microcontroller programmed and ready to go, we began to test the IGBT circuit we received. There was an expected behavior to arise from sending two pulses to the IGBT circuit; one of which was the increase of current through the IGBT. The current would increase linearly with time, but during the second pulse there would be a spike increase. This additional current is introduced by a diode due to the reverse recovery time it needs to become reverse bias again. Another point of interest is when the second pulse drops back to zero. During this time voltage Vce would experience a spike before settling back to a steady voltage caused by stray inductance in the circuit. We measured these spikes and the rise times for the current and voltage for further analysis.

This afternoon we attended the International Conference on Electronic Packaging Technology. There were many researchers from around the world in attendance, and a few of them presented their research related to electronic packaging technology. One interesting presentation was about carbon fibers and controlling their failure process. The presentation detailed the theory behind the strength of bundled fibers and their application in areas like aerospace and system design. Our own Dr. Albert Wang also gave a presentation about integrated design for reliability by 3D heterogeneous integration. His presentation discussed the challenge of developing reliable electrostatic discharge protection, and Albert proposed novel methods to improve current ESD methods in the future.

After breakfast this morning, we met up with Jiao and Dian and headed over to the lab. To move forward with our project, we first needed to develop our software for our microcontroller. We pulled together all of our software expertise and started coding away, and we managed to get a rough draft finished before lunch. After a few additional tweaks, we were able to compile our code without errors. We then proceeded to wire the MCU to the oscilloscope to see if it generated the two required pulses correctly. They had provided us with a general schematic detailing how to wire everything together, so we managed to hook up everything without much trouble. However, the students helped us setup the oscilloscope since the default language was in mandarin. With everything in place, we pressed the button to trigger the pulse. Success! The oscilloscope output was exactly what we needed, and we completed the first phase of our project.

Today Jiao and Dian took us over to the lab for the first time. The research institute we will be working at is not on campus, so we had to take a taxi to get there. Once we arrived, they took us upstairs to the lab and introduced us to the other graduate students working there. At first the other students were too shy to talk to us, so we ended up breaking the ice with a game of poker. Pretty soon we were all laughing and getting along well. After lunch, the students were ready to explain the project we would be working on. We were assigned to work with an insulated gate bipolar transistor IC to test for particular characteristics. The experiment involves generating two pulses from a microcontroller, and we would have to develop and program the microcontroller ourselves. Since the datasheet for the microcontroller we are using was in mandarin, one of the graduate students spent some time teaching us about basic register programming to initialize timers, interrupts, and setting up inputs and outputs. We had a lot of research to do since none of us had ever encountered an IGBT, but we were excited to finally begin work on our HUST project.