Howdy y'all!

So i have one more exam left!!! While i'm extremely excited about the concept of a month of freedom, the knowledge that tomorrows exam is on the horizon is dragging me down. The last two exams (industrial automation and active circuit design 4) could have gone better for me. I was especially disappointed with ACD4. In the previous 3 ACD modules i came out with 2 A's and 1 B but i think i ended my winning streak today. hopefully i am wrong.

Telecommunications is the topic of the exam tomorrow. The lecturer is pretty sound and seems to be the kind of guy who gives marks if you spell your name right. The actual content of this module isn't too difficult to understand it's just the quantity that i'm freaking out about.

The first question is a design question. For this i'm basically taking up the role as network administrator for some company who has offices throughout europe with administration offices usually in both Dublin and the Arran Islands (generic remote location). It's my job to link all these offices up, provide voice, video and data to the 1million customers within a 100km range of the major cities, make the network location aware and so on.

I have decided to go down the WiMax route for this design. I intend on linking up the main offices with some optical fibre (sidenote- apparently this is becoming cheaper to install than co-ax?!). Then for my customers, they will have a fixed WiMax point in their house or office and also have mobile capability with maybe some kind of subscription for my metro WiMax base stations.

I looked into UMTS-TDD which would have been handy if i'm offering cellular capability since it can switch to GSM when out of range. But the WiMax has better bit rates and i'm going to mention how Nokia are bringing out a WiMax phone in 2009 which can be integrated to their broadband package. Here's a good link to read for WiMax info that's delivered in a down to earth manner: Techworld

Now i just have to figure out how to make my newtork location aware. If it's for mobile phones, triangulation between base station controllers would work, but for WiFi i'll have to use some RF id thing perhaps. I know, i'll implant a GPS chip into every employee so i'll always know where they are! Problem solved.

Well i better get back to learning about cellular networks, PSTN networks and Data networks....wait...isn't that pretty much every area in telecommunications!

Today i finished my 3rd exam. So i have ASICs, Industrial Automation and Signals and Systems 2 done. I still have Active Circuit Design 4 and Telecommunications left to do and i'm pretty sure these will be the hardest.

I have to go teach maths at 6.30 which i really wish i didn't have to do because i need to study. Although realistically i'd probably just spend most of the evening watch Dexter on the internet. This is the best show out at the moment! Normally with tv shows, i get drawn in by the characters relationships with each other, but this has an amazing story line running in the background! If you haven't seen it, go watch it NOW!

So as promised here is the schematic for my temperature module



Now for a quick rundown. First, if you're reading this because you have a WiRobot and somehow got linked to this page, this circuit costs like less than 10euro to build. Compare that with the $50 before shipping on the Dr Robot website and i think it's obvious which one to go for.

The Analog Devices chip is a temperature sensor but outputs 28mV for every degree after 0. The robot detects 25mV per degree so i have a resistor network to drop the votlage down. Actually looking at this now, i think that when i built this i realised that the resistor values i had chosed to drop from 28 to 25 mV were wrong, but i can't be bothered to check this now.

The Analog Devices chip is a surface mount device which really worried me at the time because i had never soldered these before and the internet had all these crazy tutorials. In the end i just put a magnifying glass in front of the board and it was like normal soldering. The regulator (to drop from 5 to 3.3v) was tricky since this was also surface mount and since i was using these devices i couldn't use standard matrix PCB board and cut tracks. I had to go through the whole process of transferring my design to a board with UV light, etch out the pattern with acid and photoresist and then drill holes. All in all it was a good learning experience and a little fun! Next time i will possibly talk about the keypad circuit i'm going to start making when these exams are over.

Hello reader!

And by reader i don't mean in the general sense, i mean it in the singular sense.

I was about to write a little section here on how bad the weather here is, but that's just typical Irish weather. We must be the only people in the world who can maintain a whole conversation based on the weather. This is especially handy when exchanging small talk with taxi drivers. Anyway, i have to walk to the bank soon to pay my rent, teach Leaving Cert Ordinary maths in the Fountain of Knowledge and then go to the bus station to pick up my brother. All this and still manage to have time for maybe 6 hours of study.

The module i have been studying for lately is Industrail Automation. This is a very mechanical subject consisting of pneumatics, PLCs, robotics and motors. The sections on pneumatics and PLCs are relatively straight forward. When i was working for Irish Rail over the summer, i had to learn how to read pneumatic diagrams for the pneumatic door system in the DART trains, so i had a bit of an advantage over the rest of the class. The kind of PLC questions he gives on exam papers is all ladder logic programming and i like this. Motors is the biggest section but the information in the notes is very vague. For example, for permanent magnet motors, it doesn't have anything about their operation, it just says that they're the most widely used motors! I know this wont come up in the exam but it would still be nice to have more information on it, so i find myself checking wikipedia every few minutes.

I also get the feeling that the lecturer doesn't give a damn about teaching. His life seems research based and it's almost like teaching is just this secondary task which is more of a burden to him. He comes into class and just reads straight from the notes. Oh and he answers his phone if it rings, has a converstation and after a few minutes is like "anyway i'm in a lecture so i'd better go". He has a blackberry so he checks his emails at regular intervals too, heaven forbid they should go unchecked for an hour! This whole lax attitude towards teaching made me decide half way through the semester that his classes are pointless. I mean i can read the notes myself, i dont need him to do it for me! Judging by his past exam papers, he doesn't care enough to even alter the questions, so the papers are pretty identical from year to year. It's a bit of a joke.

I realise that this blog is becoming more of a college blog than an electronics one. This is only temporary while the exams are on. Come janurary, i'll be spending as much time as possible buliding the circuits for my FYP. I will possibly include the schematics on this page, but i'm not sure. One of the schematics is for a temperature sensor. It's designed for the WiRobot X-80 which is made by Dr.Robot. I could have bought this sensor from the Dr.Robot website for $50 and then there would have been shipping charges on top of that. In the end i just built one myself. I'll show the schematic in my next post. It's really basic but i'll run through it anyway.

For now i must get back to studying.

Yesterday i had my first exam, which i think i mentionned was for Signals and Systems 2. It didn't go as badly as i expected. We had to answer 4 out of 6 questions and i got the better part of 5 questions out. I dont want to overanalyse and freak myself out so i'm just going to forget about it until the results are released.

My next exam is in 6 days time and it's ASICs (Application Specific Integrated Circuits). This is mostly Verilog coding with a bit on CMOS devices thrown in at the end. Luckily for me Active Circuit Design 4 is totally based on CMOS devices to that part shouldn't be a problem. Verilog isn't too bad. 40% of this module was going for a verilog filter desgin project we had to do. Currently i'm at 30% because i still have to hand in my report for this.

This semester has definitelty been the toughtest. I know that as college goes on it's meant to get exponentially more difficult. When i told my FYP supervisors how crazy this semester has been they just laugh and say "wait till next you come back in Janurary, things really get tough then", which is zero comfort! It just seems that there's so many projects and assignments that it leaves little time for actual study.

My mother is a Lecturer in Economics in a different college. The 4th years she teaches don't take an end of semester exam because the course is based on continuous assesment. She divides this up into a 40% midterm and the other 60% goes for a research essay and a 15 minute presentation on the essay. For our telecommunications module this semester, we had to write a research essay and do a presentation on it and it was only worth 10%!!! My sister is doing science in UCD and her whole class had to go on a field trip for a weekend. It was for some kind of environmetal biology study. Apparently they were all worked to the bone for the weekend and when they got back they found out it was only worth 2% of the module.....Its actually kinda funny when you think about it, although maybe thats just because i listened to her rant about this. So in summary, if there are any leaving cert students reading this, go for economics in WIT and ignore engineering in UL or science in UCD!

Since it's December, for students that means one thing...exams. I am currently studying for one that i have in two days. The module is Signals and Systems and even though i went to practically every class, i'm still finding certain formulae hard to track down.

For instance, yesterday i was looking to find the minimum stopband attenuation for a Butterworth low pass anit-aliasing filter. I couldn't find an equation written down in my notes so i tried the internet. When it comes to certain information, the internet is IMPOSSIBLE to navigate! Most of the sites are for digital filter design, where the attentuation is given to you already and you have to come up with like a transfer function. I tried looking in a few Forums too and there was one guy who had posted looking for exactly the same thing as me but the responses were stupid. People had replied telling him to try using various different models of DSP chip when clearly he wasn't building anything but just looking for an equation.

In the off chance someone else, other than my friend Niall is reading this and is looking for an equation for stopband attenuation, well here's two that both do the same thing:

Amin = 20log(√1.5 * 2^B)

Where Amin is the minimum attenuation (in decibles) and B is the number of ADC bits.

The other formula is

Amin = 20log((A/√2)/erms)

Where A is the input signal amplitude and erms is the rms value of the quantization noise level.

I hope that if someone types stopband attenuation into google, they get directed to my site because it might save alot of time.

On another note, it's roughly 0 degrees outside. When i woke up this morning, the ground was covered in a layre of frost. Normally i love this kind of weather, but i'm studying in my Dads office unit and it's pretty cold up here. Also i'm very tempted to set up my drum kit and play in between study intervals but i dont trust myself enough to not get completely distracted.

Okay, so i have been thinking about starting a blog for quite some time now but my lack of creativity when it comes to writing always turned me off doing it. Then as i was lying in bed last night it came to me, i should start a blog about electronics!

Let me explain, i am studying electronic engineering in college, actually i'm in my final year. Which give me the added topic of talking about my final year project (maybe next post!). Initially it was my plan to continue my education by pursuing a postgrad in mechatronics or something similar. When i was talking to my mother though, she said that with the state of the economy at the moment (recession), it would be a good idea to look for a job instead and put further education on the fence. This led me to search numerous websites, mainly gradireland, in the pursuit of a career. About a week ago though, as part of one of our modules, two people from Cisco came in to talk to us about telecommunications. After the talk, i started talking to one of the guys from Cisco about their technology versus Nortels etc. Anyway he was impressed that i had previoulsy worked in Nortel (so had he) and told me to submit my CV because he'd like to interview me.

Now dont get me wrong, i liked working in Nortel and it was great networking and programming experience but if i have to get a job i want it to be in the field of electronics, hopefully R&D. I send him my CV and my parents told me that if i was called for an interview/offered a job i'd be crazy to say no, i mean it IS Cisco.

So in the event of me entering the workforce as a software engineer (heaven forbid), i want to keep in touch with the world of electronic design. This blog should also help me keep track of course work in college since i'll be posting about all the new and interesting topics we're learning about!

However, college is not my life. I'll be posting about things i like to do in my spare time also such as playing drums, collecting comics etc.

Who knows, this blog might actually become interesting!