{"id":75,"date":"2019-03-24T00:17:59","date_gmt":"2019-03-24T00:17:59","guid":{"rendered":"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s19-teama2\/?p=75"},"modified":"2019-03-24T00:23:28","modified_gmt":"2019-03-24T00:23:28","slug":"week-4-and-5-update","status":"publish","type":"post","link":"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s19-teama2\/2019\/03\/24\/week-4-and-5-update\/","title":{"rendered":"Week 4 and 5 update"},"content":{"rendered":"<p><span style=\"font-weight: 400\">Kevin:<\/span><\/p>\n<p><span style=\"font-weight: 400\">Update for week 4<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Accomplishment #1 description &amp; result<\/span>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">This week our first revision of PCBs arrived along with the parts needed to assemble it. <\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">We assembled the PCB using solder paste placed of the exposed pads. The solder paste was placed using a stencil cut from a precise vinyl cutter. The board then went into an oven where a specific pattern of heating is used to properly solder the components.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Once out of the oven we fixed a few issues with the soldering, namely some bridges on the power ICs.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Upon testing the PCB, we discovered the ESP32 was getting very hot, much hotter than it should be in normal operation. The issue was that 5V was being put into the 3.3V pin on the ESP32. I did not thoroughly read the datasheet for the ESP32 and thought 5V would not harm the device, this is incorrect. The boost converter used after the battery manager does does not regulate higher voltages down to 3.3V, instead it only boots up the 3.3V. \u00a0This resulted in the 5V coming from the USB going into the processor without being stepped down. <\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">We can\u2019t simply supply 3.3V on the power in line because the battery manager needs at more than this to operate and so the output voltage is only about 2V, this also won\u2019t charge the battery. <\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">We decided to order another PCB with changes to supply the proper 3.3V needed. We will use a Buck-Boost converter which will step both up and down to regulate the voltage to the processor at 3.3V. <\/span>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">I chose to use the TPS63001 chip for this task. It has voltage input range of 2.4V to 5.5V, which matches what we need quite well. The output is fixed to 3.3V with a ripple of about 10mV. The chip has a power saving mode, which we will be using, that lowers the switching frequency when possible.<\/span><\/li>\n<\/ul>\n<\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">We also discovered one of the the ground pins on the ESP32 was not connected because the ground pour was slightly smaller than expected preventing a connection.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">We were able to see some data from the vesper mic vout pin since the breakout section was working properly.<\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p><span style=\"font-weight: 400\">First revision pre-assembly<\/span><\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-medium wp-image-77\" src=\"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s19-teama2\/wp-content\/uploads\/sites\/17\/2019\/03\/Capture-300x240.png\" alt=\"\" width=\"300\" height=\"240\" srcset=\"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s19-teama2\/wp-content\/uploads\/sites\/17\/2019\/03\/Capture-300x240.png 300w, http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s19-teama2\/wp-content\/uploads\/sites\/17\/2019\/03\/Capture.png 329w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/p>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Upcoming work #1 description &amp; expectation<\/span>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Next week I will be working on finishing the schematic for the new board as well as routing. I will also order the new parts needed for this board and the board itself.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">I will also begin to research more on background noise reduction<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">If the boards arrive on time we will try to assemble and test those as well.<\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Update for week 5<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Accomplishment #1 description &amp; result<\/span>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">This week I finished routing the new board, Rev 0.2. I kept the breakouts for the ESP32 and the vesper mic. I fixed the ground issue for the one pin the processor and of course added the new buck-boost converter and its peripherals.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">The board was ordered over spring break along with the new parts.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">While waiting for the board to arrive, I was able to research more removing background noise from our audio data. I have a matlab filter used for hearing aids I want to try as well as audacity\u2019s noise reduction system. I need to collect noisy data to test these methods. Audacity is open source so the code for their noise reduction system is available in C++ which I may adapt to our needs if it works well. In preliminary tests it appears to work quite well. The user selects an area of the signal that is only background noise and the algorithm does its best to remove only similar sounds without destroying the good signal. <\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">The new boards and parts arrived by Wednesday and Ronit assembled it on Thursday morning. We discovered the output of the buck-boost converter was not regulating the output voltage to 3.3V. After careful inspection we found that the feedback pin had to be connected to the output voltage even on the fixed 3.3V version. I soldered a wire on the board between the to pins and it now works very well.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">The board can be powered from 5V USB or our LiPo battery without issue. At first glance it also appears to charge the battery correctly but more testing needs to be done. Importantly, the board connects to the computer and can be programmed.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">The Vesper mic appears to react to noise levels as well. <\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">We made a quick fix to the old board as well. We soldered a wire into the 3.3V line so we can power the board direction with 3.3V. We need to test if the battery can power it but we will not be able to charge due to the issues discussed in last week\u2019s report.<\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Rev 0.2 Board, main changes are centered around part U2, the new buck-boost converter.<\/span><\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-medium wp-image-79\" src=\"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s19-teama2\/wp-content\/uploads\/sites\/17\/2019\/03\/Capture-1-259x300.png\" alt=\"\" width=\"259\" height=\"300\" srcset=\"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s19-teama2\/wp-content\/uploads\/sites\/17\/2019\/03\/Capture-1-259x300.png 259w, http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s19-teama2\/wp-content\/uploads\/sites\/17\/2019\/03\/Capture-1.png 617w\" sizes=\"(max-width: 259px) 100vw, 259px\" \/><\/p>\n<p>&nbsp;<\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"alignnone wp-image-80\" src=\"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s19-teama2\/wp-content\/uploads\/sites\/17\/2019\/03\/Capture-2-300x238.png\" alt=\"\" width=\"418\" height=\"332\" srcset=\"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s19-teama2\/wp-content\/uploads\/sites\/17\/2019\/03\/Capture-2-300x238.png 300w, http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s19-teama2\/wp-content\/uploads\/sites\/17\/2019\/03\/Capture-2.png 688w\" sizes=\"(max-width: 418px) 100vw, 418px\" \/><\/p>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Upcoming work #1 description &amp; expectation<\/span>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">I will be collecting noisy data and looking at the effectiveness of the background noise algorithms I researched this week.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">If the board bring up goes well, I will start designing out Rev 1.0 for the PCB which will be more stripped down and as small as possible. <\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">James:<\/span><\/p>\n<p><span style=\"font-weight: 400\">Update for week 4<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Accomplishment #1 description &amp; result<\/span>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">This week, I worked with Ronit to begin collecting labeled sample data to work on over the break. I began researching different features used and methods to extract them from papers which accomplished similar attacks. <\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Past work has shown that cepstrum features do yield better classification accuracy than FFT. However, we want to test this for ourselves and compare FFT, cepstrum, and a concatenation of both. <\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Upcoming work #1 description &amp; expectation<\/span>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">In the upcoming weeks, I will work on extracting different features from keystrokes in an automated manner and attempt to cluster different keys based on these features. <\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">I will also need to further explore the potential classification algorithms to use. During my research of which features to use, I found a comparison of different classification algorithms and their accuracy. Interestingly, a linear classification model yielded better accuracy on test data than both a neural network and a gaussian mixture model. I will try to compare both linear classification as well as the original strategy we planned on using, k-means.<\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-medium wp-image-81\" src=\"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s19-teama2\/wp-content\/uploads\/sites\/17\/2019\/03\/Capture-3-300x239.png\" alt=\"\" width=\"300\" height=\"239\" srcset=\"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s19-teama2\/wp-content\/uploads\/sites\/17\/2019\/03\/Capture-3-300x239.png 300w, http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s19-teama2\/wp-content\/uploads\/sites\/17\/2019\/03\/Capture-3.png 399w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/p>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Changes to schedule description <\/span>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">No major changes have been made to the schedule. However, we have been shifting responsibilities around as needed in order to allow Kevin to fully complete the next revision of our PCB.<\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Update for week 5<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Accomplishment #1 description &amp; result<\/span>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">This week, I worked more on the feature extraction from the labeled keystroke data. I extracted both FFT and cepstrum features from the entire window of the push peak of the keystroke. I am currently ignoring the release peak as it is less intense in energy and sometimes difficult to pick up in the presence of background noise.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Using the FFT and cepstrum features, I attempted to classify a few different letters using k-means. When classifying a combination of \u2018q\u2019, \u2018a\u2019, \u2018k\u2019 and the space bar, I found that both the \u2018k\u2019 and spacebar were clustered fairly accurately, yielding no more that 2-3 erroneous classifications out of 20. However, the letters \u2018a\u2019 and \u2018q\u2019 were misclustered into all four clusters<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">I thus attempted to increase the feature set. I began by taking FFTs and cepstrum features over sliding windows of 5ms with a 3.75ms overlap. Unfortunately, this did not alleviate the issue.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">I also helped Kevin troubleshoot the newly arrived second revision of the PCB. Unfortunately, there was a missing connection on one of the inputs to the buck-boost converter, and we manually soldered on a wire to bridge the connection. This corrected the issue.<\/span><\/li>\n<\/ul>\n<\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Upcoming work #1 description &amp; expectation<\/span>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">I will further explore different options and features for classifying the keystrokes effectively. We are currently having some difficulty effectively clustering the data, and this is currently the biggest risk area in the project. I will take a closer look at the previous work done in this area and attempt to replicate their methods as described. <\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">We also hope that TDoA will serve as a highly distinguishing feature. Now that we have multiple working sensor packages (both breadboarded and PCB), we can begin to incorporate TDoA data into the clustering. <\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Should we still find ourselves unable to find the correct features to cluster upon, we may need to explore different keyboards, typists, and typing styles. <\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Changes to schedule description <\/span>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">We are falling behind schedule in terms of machine learning and signal processing. Fortunately, the PCB design has been mostly finalized. This will allow us to fully shift our focus to these areas. Because of the ample time for testing and integration we alloted to ourselves, we should still be on track to complete the project.<\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Ronit:<\/span><\/p>\n<p><span style=\"font-weight: 400\">Update for week 4<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Accomplishment \u00a0description &amp; result<\/span>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">We collected data for each individual key. We recorded 30 keypresses pressed with the index finger.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">I worked with James to extract features from the sound. We got some features but decided to work on them further after spring break.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">I worked with James on keystroke separation, we read the paper Acoustic Keyboard Emanation Revisted Zhung et al. It described a means of extracting keystrokes from a sound clip by creating 10ms windows and examining the the change in the energies.<\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Upcoming work \u00a0description &amp; expectation<\/span>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">After spring break, we will probably have the new batch of PCBs.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Once we have a working remote listening device, I will make the processor sleep and only wake up when sound is detected.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Once we have a working sensor package, we will need to work on adapting our network stack to support data from two devices, so that we can extract time difference of arrival.<\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Changes to schedule description <\/span>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">I will be helping James with the machine learning from here onwards, we need to try and reach out MVP as soon as possible<\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Update for week 5<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Accomplishment \u00a0description &amp; result<\/span>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Kevin made changes to the PCB over spring break and ordered new ones.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">I assembled the PCB, there was some issues with the power management circuit, but we managed to solder a wire on and fix it.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">I was able to flash our program onto the PCB and connect to the internet.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">In parallel, I have been working on the machine learning. The problem we are trying to solve is a substitution cipher. Brute force was fast but noise threw it off very easily. We found a naive bayes approach and attempted to use it. It was resistant to noise but was exceedingly slow.<\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Upcoming work description &amp; expectation<\/span>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">My work going forward will be focused on machine learning and battery conservation on the ESP32, now that we have a working remote listening device, we need to make sure it meets our laid out target of being able to run for 12 hours on one 200mAh battery .<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">We may have to recollect the data, the collecting data by recoding individual key presses may not have been the best idea. Preliminary tests using the clustering algorithm show that letters that are located physically close to each other are being put in the same cluster. This is to be expected, but we were hoping to see more separation. <\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Changes to schedule description <\/span>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">We are trying to reach our MVP as quickly as possible, we are seeing routes for optimization for the PCB as well as our processing pipeline, we are making a record of them but right now our main focus is on achieving the correctness. These optimizations, especially for the processing pipeline will come in handy when we try to reduce our compute time.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">We have fallen behind in the machine learning, we will be collectively working on it starting next week.<\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Team:<\/span><\/p>\n<p><span style=\"font-weight: 400\">Accomplishment #1 description &amp; result<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">We built the second revision of the PCB, initially it seemed to draw too much voltage and was having the same heating problem as last time. We found out that it was because we left one of the pins on the buck-boost converter hanging that we should have tied to the output. We managed to fix this with a botch wire.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">We also managed to program the board and run our program on it. Next week we will be testing the microphone and making sure the peripherals work as intended.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">James managed to extract cepstral and fft features. He ran K-means clustering on it, but it yielded poor separation on keys that are physically close to each other on the keyboard.<\/span><\/li>\n<li style=\"font-weight: 400\"><\/li>\n<\/ul>\n<p><span style=\"font-weight: 400\">Upcoming work #1 description &amp; expectation<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">After spring break, we need to try and get our new pcb working. It should work now that we use a buck boost converter.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">We need to extract features so that we can begin the machine learning. We will be using cepstral, fft and TDoA to cluster the features. <\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">We also hope that TDoA will serve as a highly distinguishing feature. Now that we have multiple working sensor packages (both breadboarded and PCB), we can begin to incorporate TDoA data into the clustering. <\/span><\/li>\n<li style=\"font-weight: 400\"><\/li>\n<\/ul>\n<p><span style=\"font-weight: 400\">Changes to schedule description <\/span><\/p>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">There will be a major shift from embedded coding and PCB design to machine learning and signal processing. We need to achieve our MVP as soon as possible so that we can begin refinement and testing. <\/span><\/li>\n<\/ul>\n<p><span style=\"font-weight: 400\">Any other major change to your project on a high level<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">There are no major changes to the project at this moment.<\/span><\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400\">Team:<\/span><\/p>\n<p><span style=\"font-weight: 400\">Accomplishment #1 description &amp; result<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">We built our first revision of our PCB, Upon testing the PCB, we discovered the ESP32 was getting very hot, much hotter than it should be in normal operation. The issue was that 5V was being put into the 3.3V pin on the ESP32. This required switching from a boost converter to a Buck-Boost converter to step the voltage both up and down. A new schematic has been created and the order will be put out soon.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">James and Ronit collected labeled data for every single key.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">James and Ronit implemented the keystroke separation as described by the paper by Zhung et al. After some noise reduction, we were able to get the keys separated rather well.<\/span><\/li>\n<\/ul>\n<p><span style=\"font-weight: 400\">Upcoming work #1 description &amp; expectation<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">After spring break, we need to try and get our new pcb working. It should work now that we use a buck boost converter.<\/span><\/li>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">We need to extract features so that we can begin the machine learning. We will be using cepstral, fft and TDoA to cluster the features. <\/span><\/li>\n<\/ul>\n<p><span style=\"font-weight: 400\">Changes to schedule description <\/span><\/p>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">We will try to get the machine learning as soon as possible, as we think it will be the most challenging portion of our project.<\/span><\/li>\n<\/ul>\n<p><span style=\"font-weight: 400\">Any other major change to your project on a high level<\/span><\/p>\n<ul>\n<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">There are no major changes to the project at this moment.<\/span><\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Kevin: Update for week 4 Accomplishment #1 description &amp; result This week our first revision of PCBs arrived along with the parts needed to assemble it. We assembled the PCB using solder paste placed of the exposed pads. The solder paste was placed using a stencil cut from a precise vinyl cutter. The board then &hellip; <a href=\"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s19-teama2\/2019\/03\/24\/week-4-and-5-update\/\" class=\"more-link\">Continue reading <span class=\"screen-reader-text\">Week 4 and 5 update<\/span><\/a><\/p>\n","protected":false},"author":45,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[],"_links":{"self":[{"href":"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s19-teama2\/wp-json\/wp\/v2\/posts\/75"}],"collection":[{"href":"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s19-teama2\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s19-teama2\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s19-teama2\/wp-json\/wp\/v2\/users\/45"}],"replies":[{"embeddable":true,"href":"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s19-teama2\/wp-json\/wp\/v2\/comments?post=75"}],"version-history":[{"count":4,"href":"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s19-teama2\/wp-json\/wp\/v2\/posts\/75\/revisions"}],"predecessor-version":[{"id":83,"href":"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s19-teama2\/wp-json\/wp\/v2\/posts\/75\/revisions\/83"}],"wp:attachment":[{"href":"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s19-teama2\/wp-json\/wp\/v2\/media?parent=75"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s19-teama2\/wp-json\/wp\/v2\/categories?post=75"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/course.ece.cmu.edu\/~ece500\/projects\/s19-teama2\/wp-json\/wp\/v2\/tags?post=75"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}