 of my semester three electronics project. Semester three was, I was just starting electronics majoring in my university. So we were new to the department. Lots of professors didn't know us. So we were given a simple project to build a UR transmitter using visible light. We can't use laser or anything. So the project basically had two problems to solve. One is the electronic circuit itself, and the other one is the transmitter. So the main problem was the electronic circuit because we just finished semester two. Semester two was more into theoretical stuff. So we didn't have any practical experience. So but we knew what the fundamentals of electronic is. So with the knowledge we had, we came up with few devices which we might be needing for this project. So we thought we might need resistors capacitors and some diode and transistors. To amplify the signals, we might be needing some op-amp and to capture the variation in light. We need photo resistors and photo transistors and LEDs for light source. So with this device, then we thought what could be the possible concept we might be needing. So we need to build a UR transmitter. So we need to know what is your protocol and how we transmit a signal. So we need to blink an LED according to the bit stream. So then we need to know how to calculate op-amp gains and how to design the comparator circuits and then cascade them to get the final output. So then once we build the circuit somehow, then how are we going to test it? So we thought we might be needing this list of devices which we already had in the lab. We thought we might be needing a multimeter to measure different voltages at the different stages in the circuit and an oscilloscope to see if the waveforms are correct and a function generated to input a square wave and see if the same waveform is getting from the output and frequency counter to count if we are sending eight pulses navigating eight or seven or nine pulses and the logic analyzes to see if the logic low level of power circuit is the logic low level the UR module is expecting. Likewise, we thought we might be needing these devices. So with this set of things in our mind we first designed a model. We first came up with a rough sketch on a piece of paper and for that we used some very old op-amp for LM741. That's very legacy. And unfortunately this circuit didn't work for us. Just because we started our semester three we were new to the department. We couldn't just use our electronic lab whenever we want. So we had so many restrictions. We first had to get an approval from a professor saying that he would take responsibility if we break any stuff and there needs to be a lab assistant in the lab at the time of our working. So it has to be from 8 a.m. to 5 p.m. and our timetable needs to have a free download. So all these factors should come together for us to debug the circuit and go to the lab and debug the circuit. So it was pretty hard for us to debug what was the problem with the circuit. So I thought probably the IC is burned and then I bought another few more ICs. And I must say they didn't even work. So I put a question on the set of low and got to know that there could be whole batches in 4G. So then I thought of buying myself an oscilloscope because it was so hard to go to the lab and to get permission from each professor. It's quite troublesome, but then I checked the price of an oscilloscope. It was so expensive. So I let the dream burn and then some of we came up with a different circuit. It fortunately worked the first time I plugged it in. So then we moved on to prototype, we moved on to the dashboard and the circuit did really work. So as a final design, we moved on to PCB and came up with two of these devices which we can connect to different pieces and communicate using UR. So the projector serves as well. So I was wondering what if we had a PS lab back then. Actually back then there were no PS labs. It was developed for nearly four years for now. If I had a PS lab, I would have all the testing devices in a small device, something like this. Just a size of rocket science lab. And if you consider the price of each, each of those testing equipment separately, it would cost you more than thousand of dollars. But the PS lab is very cheap compared to that time. Upon the last one, we were developing different, different hard prototypes to come up with a cost effective and ergonomics design. So finally, we came up with this final design. This is the actual PS lab now. So it's a four layer board with all the components mounted on the top side. So actually what does this device offer you? I had many workshops lately, two or three workshops. So most of the people seems interesting in the possible scope. It has four channels. That means at a given time, you can see four different waveforms on your screen. And it supports a sample rate of two million samples per second. That is quite a reasonable sample rate for most of the electronic projects you have. And then it has a voltmeter, voltmeter with six inputs. That means you can measure six different voltages at the same time, as you can see. And then it has three different ranges of programmable voltage sources, ranging from plus to minus five volts. And then you have a current source which can supply up to 3.3 million. And it also has a four channel logic analyzer which can support frequencies up to four megahertz. And it also has two wave generators. It could be at the sine or a triangle waveform with frequencies ranging from 10 hertz to five kilohertz. And then you have another four pins to generate positive-modulated waveforms. And as for the multimeter functionalities, it can measure capacitance ranging from picofarad to mitrefarad and resistance from milli ohms to mega ohms. And it also has a breakout connectivity for I2C sensors. So if you have a humidity sensor or pressure sensor or heat temperature, anything which works with I2C, you can connect it with the device. And from the desktop application or the Android application, you can capture the data the sensors are providing. And it also has a frequency counter, just like we would have required in our project. So this whole thing comes in a different project called PSLAB project. It was, apparently last year, it was a branch of 4-stage organization. If this year Google Summer of Code, PSLAB is applying as a different organization because there are so many repositories to manage. So it's difficult to manage if it's in the same organization. So PSLAB is a different organization this year in GSOC. So it has PSLAB Python and PSLAB desktop app for the front-end backend for PSLAB desktop application and PSLAB Android repository for the Android application and PSLAB remote web server and firmware for the PIC microcontroller in the PSLAB and hardware containing all the schematics and build-up materials anyone would need to build the device himself. And it all started with a C-lablet. It was a very basic device, containing two-channel oscilloscope and a few IO pins. And then we developed this hardware device. The first application was desktop application. It's developed in Python. And last stage is so we developed the Android application. And this stage is so we are planning on completing the desktop application and Android application with some additional features and front-end areas of web app. Because at the moment, Windows users cannot really use the application. So with the web app, the usability will be increased in huge numbers. So this is how the Android application looks like and this is how the desktop application looks like. So I will be having another workshop tomorrow at maybe around 10 a.m. If you have any questions you can ask now we can catch up in the workshop tomorrow. Thank you.