SHIIAAATTTT.
It’s not working. Damn thing decided to crap out on me ON THE FREAKING PCB after assembly. A criteria I didn’t meet? Yeap. It didn’t go past 10V peak to peak. It barely brushed past 5V p-p. Oh Em Gee. Screw it. Handed it up last Thursday, with my project report following it on Monday next week. I hope that my lecturer will accept my half-arsed reason for it not working. Not fluff and bullshit, mind you, but proper analysis on the problem and why the damn thing didn’t work. But still, I call it half-arsed reason because there wasn’t any proof of the failure attributing to the fact, it was more like I tied the failure to the fact through self-analysis and observation. Should work? I hope.
Btw, the project website is up, albeit a temporary one. It’s still ‘work in progress’, but it has my group picture as well as (soon I hope) the project description. Project group name = RC2.
Left to Right : Shang Wen, Me, Robert Li
Endeavour 2007
ECD 3 though, is moving towards the end (thankfully!) with the project on the final dregs for the hardware and software section. All that will be left then is the report, which I hope I will write in a state of mind that does not lean towards fluff. Or plain long-windedness.
Project work? Don’t ask. We had to scrap our 5 weeks of work today when the algorithm that we were using right until 6 hours ago had to be scrapped. Complications in the algorithm were the main cause, and we hammered out a simpler algorithm that wasn’t so memory hungry and might even be faster in the end. Now, we will be concentrating on our PCB design as a prototype as well as having it as a development board.
Ah well, hope I don’t fall sick again.
KW
One of my favourite subjects. The lecturer is fun, and the projects are tough but they are exactly what I like to do. Lucky for me, I did not take this subject in my third year (this subject is a third year subject) but I opted to do it this semester as an elective instead. Last year it was taught by another lecturer, one who wasn’t as fun as my current one. Even so, he’s gonna be teaching us for the second half of the semester. You can’t have everything can you? Hehe.
This year, Graeme (my lecturer) had this great idea of giving us a project that we have full control of. Of course, datelines are controlled by him, just that we have free reign on our project design. We were asked to design an audio amplifier with the following specs:
- operate from a single 15V external power supply
- have input impedance > 10k ohms
- have a 3dB frequency response (nominally) 400Hz – 18kHz
- have mid pass-band voltage gain with magnitude of (nominally) 18
- be capable of driving an (external) 68 ohm load with at least 10Vpk-pk
- AC coupled input and output
Following components are available:
- LM741 op-amp + socket
- 2N3904 (NPN BJT)
- 2N3906 (PNP BJT)
- 1N14148 (small signal diode)
- 47 uF 25V elec. Capacitors
- 68 ohm 0.5 W resistor
- PCB pins
After preliminary design on PSpice, a simulation tool for circuits, I managed to build up a circuit that fit the required categories. Actually implementing it on the breadboard gave me lots of grief though. As usual, a lot of things are idealised in simulations, and this ‘idealisation’ sometimes kills the design. After many optimisation processes, I finally am able to construct a circuit that is barely able to meet all required criterias.
After that stage, PCB design came. Implementation was fairly easy (for me) and I handed in my design last Tuesday. The PCB boards came in on the following Monday (technically yesterday since it’s 12.48am for me now) and I completed soldering the thing that day itself. I have not tested it yet though. *Shudder* Knowing the problems that plagued me when I worked on the breadboard, I hate to think the debugging issues associated with this. Ah well, these are the pics of my completed project on PCB.
PCB is missing the op-amp, which is supposed to sit here: (the op-amp is still on my breadboard) – Finger looks fat (check out the PCB size on the next pic)
Size of the PCB as compared to my Sony Ericsson Z800i. For those who haven’t seen the Z800i, the size of the board is 1.95″ x 1.7″. Use a ruler. Small eh?
Now you know what actually sits in those big ass speakers around :) Implementation and design might be slightly different, but the idea is the same.
KW
Hehe… Finally pictures for my temperature sensor!! Unfortunately i don’t have the luxury of friends taking photos during or after my presentation, so I can’t show you a picture of me in smart clothes. Nevertheless, here’s the project picture. :)
Picture of the components (lower layer):
KW
Hehe thanks so much to Sian Siew for updating my blog theme. The old one was nice, but the column width a little too small to do any serious blogging. (I don’t want my blogs to be merely 3 lines thick =/ )
Ok… Back to topic. Being a final year student, I’m allocated a project to work on. Along with 2 other teammates, our project will be a year long thing with a final year presentation to the public as well to our supervisors.
Project Name: High Speed Vision System. Project code: RC2 (RC standing for Robocup). Below is a project description by Robert Li, one of my group members:
“One of the most important aspects of a robot is its sensing/vision system.
This project is to realise sophisticated object recognition algorithm on hardware which is designed to be used on robotic platform but will also be compatible with a board range of industry applications. Highly accurate ball tracking and moving target recognition at high speeds is the ultimate goal of this project.
By using a high resolution video camera and a specially designed mirror, robots are able to “see†a 360 degree image (essentially a top down view of a defined area). A Field Programmable Gate Array (FPGA) is used as a primary mean of speeding up the process of object detection. It’s extraordinary concurrent processing feature allows processing different coloured objects simultaneously and pipeline processing each pixel as it comes into system. External Synchronous RAMs are used to support large volume of data while maintaining high speeds.”
Since we were needed to submit our own project descriptions, I believe the text above neatly summarises our project aims in a nutshell. That being said, the complexity of it is enormous as we are going to integrate the algorithm into hardware (the algorithm being realised last year by a group of students, Ni Ma and Nathan Williams. Their project website: http://fpga-vision.sourceforge.net/
Current issues that we are addressing:
- Bus size to interface with the processor board. (which is managed by Boon Chong Khor, Nicholas Seng Tatt Yeoh and Shubham)
- Building our very own development PCB board since the RAM chips used in the stock dev board is DDR-RAM and we’ll be using SRAM.
- Timing issues with processing frames ‘as they come’ (hence high speed) as well as application consideration (the speed which is required by the application)
The vision system that we will develop will ultimately be used in the robots that are representing my university in future Robocup tournaments. As I go along with the project, I will post some pictures of our progress as well as the actual robot itself.
Ahhh finally… Design Lab is done and over with. Overall the project was fun to work on and the group was certainly a pleasure to work with. We had our presentation which we felt we did pretty well, and it was sad when I had to pack up the stuff that we used throughout the semester. Oh well… At least I’ve got the veroboard (it’s working!) to remind myself of the experiences I had…
Looking at other ppl’s blogs and stuff… Made me wonder what should I actually base my blog on? Writing stuff about my everyday life is fun… but it gets boring and monotonous after a while. It’s not like I lead a very eventful life, with extraordinary things happening everyday. And I certainly won’t post up on my personal experiences with my gf. Nope. That kinda thing is private. :)
So… I sorta decided to post up on stuff I actually learnt, which I hope will open up the eyes of people who see my blog, on what am I doing and how it applies to everyday life. And… what I’m studying now has EVERYTHING to do with what you guys see, hear and use. Electrical Engineering is the source of technology that provides people with comfort and ease of doing anything, right at their fingertips. Interesting huh?
KW
It’s coming along very well now, with a few things to finalise, and just the program to get working. We missed the PCB design deadline (screw it) so we are definitely implementing our project on a veroboard, with a prepared draft for the PCB design to net us some extra marks.
I hate debugging :(
T3h B1gg3st N000b. Me. Spent a week trying to figure out what was wrong with my circuit and code. The microcontroller was not responding, so that really worried me and Khor. We went through the data sheets countless number of times, trying to find a clue to what went wrong.
Then Khor found it. A misplaced wire. Mclr, which was supposed to be tied to a HIGH, was tied LOW. And guess who set the circuit up? Me. /cry. We weren’t set back by that much though, but this means we won’t get to present our circuit on a PCB. Ah well, a veroboard will work as well.
It’s worrying me. 4 weeks into the semester and the circuit has not been built yet. Graeme sort of set us the pace by asking us to play around and familiarise ourselves with the components, but I feel the time PLAYING around with the components is a bit too… scary. Anyway, we decided to understand how the components work by the end of this week, and hopefully get a circuit up and running by the end of next. We also decided to use the simplest (and most device intensive, i.e, expensive) circuit for the time being. After getting a working circuit, we could then do a major overhaul on reducing the components needed, and crack our heads on the software part. Drawback of a simple circuit: Blardy hard to write software code.
After burning two 7-segment displays, I got the displays to count up by using the PIC to control the output. We also suspect the ADC is also fried. ^_^” Well, this goes without saying since we just slapped on the voltages and the inputs without reading through the datasheet properly first. Gonna test the ADC again tomorrow. Hope it works.
Till next time.
Fell sick yesterday. Actually, it was on Tuesday night that I felt unwell. Caught a cold i think. Lucky I had Mei Yen around to help me cook porridge and get medicine for me.
Design lab is going on well, I think. Not much progress, but we’ve learnt how to program the microcontroller. All that’s left is to wire up the sensor to the ADC, and the BCD to the display. After that we can wire it up to the microcontroller. I suggested that we program the PIC in conjunction with the wiring up so we would know how the data will move. A lot of minor things that we have to take into consideration since they all add up to one big problem later if we don’t.
Luckily for me, my laptop has a serial port. The microprocessor programmer needs to interface with the comp through a serial port, and I was worried that I can’t work from home. At least now I know I can bring my laptop over to the labs, program stuff, and bring it back home to tweak around with when the lab closes. The programming of the microcontroller can be done using a Jaycar programming kit and a computer with MPLAB. MPLAB is a free software, downloadable from http://www.microchip.com/ . Just look up MPLAB IDE and it should direct you to a list of possible links. It should be the first link. They also provide you with guides on how to use MPLAB. The programming is very low level though, something along the lines of VHDL, so be prepared to change your mindset if you’re a high level language programmer. :)
Got my design lab sepcifications yesterday. My project partners are Khor and Daniel. A pretty interesting project that we’ve been allocated to, the Digital Thermometer, which converts Analogue sensing of temperatures and converts it into digital values to be displayed on two 7-segment displays.
An online logbook has been set up by Khor, and for those who would like to keep track of what we are doing, visit http://dl22a.blogspot.com/Â :)
I might post up a personal logbook of my own on this blog, probably not a very detailed one, but it should contain those breakthroughs and progress that we make.
Till next time…
