[attachment=2] One of the first things I have done with this so far is fix my camera. I bought a cheap SD card that fell apart in the slot, leaving some plastic bits behind. After some picking around with a needle and the microscope, I was able to fetch most of the parts.
How many people go to these things? Is it like a little room with 15 chairs, with desktops and dev kits set up for each individual, or is it like 100 or more people all sitting in folding chairs watching a presentation?
I aim to eventually be able to have the theme "installable" via wordpress instead of uploading it into the themes directory, but for now it will be left as is. Sad that I am not getting much feedback about the site itself but oh well, I just assume it is either that awesome or that bad, hopefully awesome! :P
I have been very sick for the past few days, so little to no work has been done, but I have a long weekend due to jewish holidays resulting in no classes for two days, during which I aim to get lots done. I even reinstalled windows onto a new harddrive, jumping from a skimpy 50 MB/s read drive to a nice and big 120 MB/s read drive. Lightroom opens faster now and picture editing is a bit less tedious now, hooray!
Anyways, thanks for the welcomes guys! :) PS: Really digging that USB connector with the open hardware logo in it Ian!
Edit: Here are some pictures from the xray and the macro photography.
Nice job fixing the board, nearly every time a board gets done and comes back, there is a mistake somewhere in some form, either in the silk screen or copper or drill holes. :P
You can always play a game of cards on a low refresh late LCD, or a text based game!
I am also curious about what camera you used to take these pictures, as I see some noise in a few pictures and the glare from the LCD with the backlight on.
I see that the CY8C38 family 8051 goes up to 67 MHz, so I would say go for the 8 MHz crystal since you can do a nice full integer with the PLL. In this case, 8 MHz * 8 is 64 Mhz which is close enough to 67 MHz while with the 24 MHz crystal you would have to do 2.7 for the PLL. Also, the datasheet seems to show that the range for the oscillator is from 4 MHz to 25 MHz, so 24 is quite close, but I don't think it really matters in this case.
Oh, I think I just realized why he has a 24 Mhz crystal on there. It gives him a perfect clock for USB.
Quote
6.1.1.2 Clock Doubler The clock doubler outputs a clock at twice the frequency of the input clock. The doubler works at input frequency of 24 MHz, providing 48 MHz for the USB. It can be configured to use a clock from the IMO, MHzECO, or the DSI (external pin).
I am really curious about your opinions about this chip compared to a PIC32 or even the lower PIC families. This possibility is certainly not avalile with any PICS I know of! Very cool!
Quote
The boost converter accepts an input voltage VBAT from 0.5 V to 3.6 V, and can start up with VBAT as low as 0.5 V. The converter provides a user configurable output voltage of 1.8 to 5.0 V (VBOOST). VBAT is typically less than VBOOST; if VBAT is greater than or equal to VBOOST, then VBOOST will be the same as VBAT. The block can deliver up to 50 mA (IBOOST) depending on configuration.
It has been a long time since I was here, due to being on vacation for a while with very unreliable internet, so I am back in (hopefully) full force. I continued work on a writeup template for electronic projects, and I would like to share it with the DP community for any possible suggestions and if anyone is interested.
I also set up a wordpress theme based on my website in the form of a blog, so if anyone wants to use my theme with wordpress for a blog or anything else, feel free to use it! :) It is in the folder on github called TOOLS/WP_THEME. You make a folder in your themes in wordpress and then upload the contents of the WP_THEME folder into it.
So far I have a google maps ish viewer for boards that you would want to zoom in a lot without having to load the entire image. Its main purpose is to be able to zoom in on objects that have lots of fine detail while not limiting the viewer to just one section of the image. I used Pano3js for this, and the script that they supplied did not work well at all, like it names the files in the wrong order, so I added in a script of my own that renames all the files correctly, which I uploaded to github in "tools" if I am not mistaken. *Uploaded just now actually* I will show how to use the scripts later in a blog post and readme text file added to the site. Also, I put in a documentation ideas text file which includes all scripts and tools that I came in contact with while searching for what ever I needed at the time, and all the top contenders I had for scripts and other items for the website. It may prove very useful if you are planning to do a website like this yourself, as I also included notes on which ones are not that good for what we want them to do.
I am also deciding on what license to use for the site and associated tools, but a major slow down is I don't know if I can license the website itself and associated stuff with what ever license I want considering I am using software like super-sized which uses a GPL/MIT license. So, for the time being, the website and all its content is licensed as do what ever you want with it, even if it makes you money, as long as you give credit where credit is due.
Now comes up the actual writeup page. It is not done yet, but I did fix and spelling and grammar mistakes that I found, but I might have missed some. It is a continuation of the Xray machine that I found right before summer, and a closer look at the sensor and its associated boards. It is a continuation of the earlier thread, viewtopic.php?f=56&t=3945
I am very open to any and all suggestions and opinions on the current writing style, layout, colors, and what ever else you may comment on. My main target right now is avoiding a wall of text while still being easy to read, so layout comments are welcome! Also, I am very happy to be back on DP! :) I already have a queue of projects to post up, like the fixing of an LCD, scavenging parts from old computers, (hopefully) a youtube video showing how I get some macro shots, and more!
In short, hello DP again, I am glad to be back. :)
It totally popped out of my head that it could be Beryllium, but it does make sense for it to be used here. If the vacuum really did drop, then I doubt I will be able to fix that as I do not have a proper vacuum pump with an oil diffusion pump or turbo pump. (always looking on ebay though)
Instead of capturing it with a camera from a distance, or gutting the camera and sticking the camera sensor right under the fluorescent screen, maybe somehow get a scanner under it and disable the lighting? First thing I want to do though is get the Xray head to actually generate Xrays, and then see if the sensor is still working. If not, then I will work with what I have and think of some other use of this guy. If the Xray head is dead, then you can expect a messy tear down of that too. :)
Wohh, the AVR seems to have a lot more instructions than the PIC's do! I am only familiar with the PIC assembly sadly.
The reason for assembly taking a back seat to C in stuff like this is for a few reasons. Like bearmos said, it is a lot easier to maintain and develop because for starters, it is far more readable. Also, C provides a very good level of abstraction. In C all you need to do is write a for statement, and the compiler generates the assembly and from there the machine code. If you wanted to do that in assembly, you would have to find the instructions for it, and assembly is very very specific to the CPU and architecture. It is not really worth it for most hobbysts to learn assembly for each microcontroller they use, because we tend to often try out many, not to mention that it is very time intensive to REALLY learn assembly for a given mcu.
And, sometimes the concept that hand written assembly is faster than C goes flying out the window when you begin looking at more complex instruction sets, such as X86. Often times when you have a CISC architecture, a compiler will do much better than a human at fast and small code, take a look at how GCC does it for example. When you look at it, just as you are looking at the assembly for the avr, it looks ridiculous and over the top, but actually it is employing tricks to make it go faster which many humans never even considered. Though, this depends greatly on the compiler. If the compiler is garbage for example, or no optimization's enabled, it will make horrendous but maybe readable assembly, but if the optimization's are all enabled, then chances are it will create very good code in terms of speed and space, but be nigh impossible to read.
Though, writing in assembly is EXTREMELY satsfying, for my at least. I did it with the PIC18F's to just blink a led, then incrementing of a value and displaying it on leds, and it was a blast, and I learned a huge amount about the way the mcu functions, which let me code better in C too.
Ok, end of long speech. :P Some of the instructions that should interest you are - STS (Store Direct to SRAM) - NOP (No operation, wastes a cycle, used for delays) - CALL (Call Subroutine) and one of the branch's
When you do assembly you are essentially getting rid of all the abstraction C provides, but you get access to a lot more, and if you know what you are doing, can get it going much faster than what the compiler is currently generating. Best of luck! :)
Agreed, but as said in the thread on 4hv, taking it apart will likely spew mineral oil everywhere. :P And I don't feel like I know enough about Xray to put it back together properly without posing a risk when turning it on again later.
But yeah, my end idea is to use this for BGA ic's, or just anything else which comes to mind that I could use Xray for. All I really need to do at the end is turn on the xray head and control the strength, and how to fetch data off the sensor. If it really is just a fluorescent screen on top of a normal CCD or CMOS sensor, then I can stick a normal camera under there, or with a mirror so I don't wreck it, and get the image that way.
Also, Ian, feel free to change the name of the post from SMD to BMD. I might have typed SMD in my post somewhere by accident, in which case my apologies.
[quote author="bearmos"]If you're getting down to shaving off a few cycles, I'd probably look at the assembly being generated (keeping in mind how many cycles each instruction takes) and go from there, sometimes you can reconstruct things in a way that's a bit more efficient.
That being said, the code you have looks to be pretty minimal to me, not sure if hand-tuned assembly would be better than your compilers output or not. Sometimes you can shave off some time by specifying where things are located in the memory space (I'm not at all familiar with the AVR architecture, not sure if this applies).
You're also going to incur some delay entering the ISR (pushing some registers onto the stack, jumping, etc). If you can live with it, polling on the timer2 flag would eliminate the latency from the context switch entering the interrupt. Sometimes, rethinking program flow to accommodate a polling approach instead of interrupts is necessary.[/quote]
Agreed with everything here pretty much. :) I was always thinking of interfacing with a cmos sensor myself, but I could never find the datasheet for it, and it is in a non working camera so I wouldn't be able to even sniff it with my logic sniffer.
Why not just hand write in assembly a loop for fetching the data off the sensor instead of using an ISR and timer? That should definitely save you quite a bit of cycles if you do a loop in assembly without using the timer. If delays are needed, just stick some NOP's in there.
If it was really designed in the late 90's then I think that back then the super nice CAD packages like altium or even eagle were not the norm, so maybe it was still designed by hand? I don't know though, as the late 90's are not really THAT long ago, and I think that if not eagle then other CAD software existed out there for PCB stuff. It is unclear though what chip is delivering the temperature sensor on the motherboard, for all I know it could be the northbridge or southbridge, or indeed a nice and east SOT23 ic. My main thing now though is to dump the HDD contents and put it online (copyright be damned), and find out some more about the sensor and xray scanner.
http://http://archive.hak8or.com/pictures/Xray_Teardown/P1260043.JPG The unit takes two X-ray images of the finger, each with varying strength. At first I would expect it to just vary the strength by changing the voltage to the X-ray head, but I am guessing that instead it was cheaper to just put some metal between the X-ray head and the finger. There is a linear actuator which pushes a lever that the metal disk is attached to, pushing the disk out of the way of the X-ray head. This is explained more on the AccuDexa site in the user manual. The two rods that stick out above the finger are what hold the finger down to prevent movement when taking the X-ray, and the big lever seen earlier is attached to them.
http://http://archive.hak8or.com/pictures/Xray_Teardown/P1260046.JPG At first thought, I would expect this unit to just deliver the X-ray, and for the doctor to put in the X-ray plate under the finger to capture the image. When looking at the pack and the user manual, it turns out I was wrong, it does even more. At first, you would probably think, why is there a floppy disk thing in the back? Machines that just send X-rays are not that complex, there would not be a need for a floppy disk in such a machine, especially if it already has a screen on it. It actually has an X-ray camera built in, under the finger. The floppy disk is for storing the "report" which includes the X-ray image and some patient information.
The machine does give you information such as bone thickness and other stuff, all of which is not that relevant to us, but now we know that it has to have a processor capable of analyzing the X-ray image. Not to mention that if it saves a report to a floppy disk which is going to be opened on another computer, it has to have file system drivers. The connector on the back is for connecting to a printer which works with a normal computer using a parallel port, so it also has to have drivers for that. This does not seem like a task for a MCU, but instead for a more full fledged system. So, just from looking at the back of the unit and the user manual, we now know that it has a high voltage supply for the X-ray head, a touchscreen LCD, a floppy disk for storing documents, and probably running an OS of sorts.
http://http://archive.hak8or.com/pictures/Xray_Teardown/P1260072.JPG The user interface for the unit are the big lever for the rods to prevent the finger from moving during the X-ray, the touchscreen, a power enable light, an X-ray enable light, and uh oh. A keyed switch to turn the unit on. Plugging in the machine does nothing, expected since the key lock is turned to the off position. Since I sadly do not know how to pick such locks yet, and a screw driver is not able to make it turn, time to take it apart and bypass it.
http://http://archive.hak8or.com/pictures/Xray_Teardown/P1260085.JPG The big lever can be taken off by just unscrewing it, and the screws for the unit are luckily not some security ones. Now, this is surprising. At first glance you can spot the power supply on the top left, two huge capacitors, the big white cylindrical X-ray head, and a hard drive with an IDE cable and a molex power connector. I am starting to think that they just shoved an entire computer into here. But I will restrain myself from pulling it apart even more and instead focus on getting it to power on first.
http://http://archive.hak8or.com/pictures/Xray_Teardown/P1260084.JPG And here is the front of the unit. A small overview of what is what from first glance. The top right square is the slot to put the patients hand into, the slot next to it is where the big lever went. Under that is a rectangular PCB, which is the CCFL driver for the light to the right of it. It takes the low voltage (12v probably) and using a transformer generates hundreds of volts to ignite the CCFL, and then steps to a lower voltage to drive the CCFL. The PCB under the CCFL driver is a very simple one sided board, no silkscreen or solder mask even, and it has two triacs, though I do not know what it is for, my best guess is contrast and brightness adjustment for the LCD. The very large board under the simple rectangular board is the touchscreen driver, with what I am guessing is a parallel data cable. The cylinder on the right of the touchscreen board is the X-ray indicator, then the power indicator, and lastly the key power switch.
http://http://archive.hak8or.com/pictures/Xray_Teardown/P1260086.JPG A closer look at the power switch reveals some identifiers of the key, and that it has four wires. Since they are colored black and white, and seem to have thick insulation, I am guessing that it is carrying mains, not to mention the heat shrink over the connectors to the key switch. A look at the datasheet of the switch gives us some good information, though I was unable to find the same model as the one in front of me. Since I was unable to find the pin out, and I do not have any heat shrink on hand, I decided to try and just take it apart, forcing it into the on position, motivated by the data sheet saying "Switch installation is permanent. Switch cannot be removed from lock after assembly."
http://http://archive.hak8or.com/pictures/Xray_Teardown/P1260101.JPG It works! Awesome! Nothing seems to be melting, smoking, or catching fire, which is all very good news! Looking at some of the files it is checking, I am guessing it runs MS-DOS or windows CE or something of the sort. Though, look at the date! 1998! This machine is extremely old, probably cost a fortune back then.
http://http://archive.hak8or.com/pictures/Xray_Teardown/P1260107.JPG Ah, I knew everything was going too well. The temperature in the basement is indeed within the specified temperature range given on the screen, but it does not seem to matter for the machine. The manual says to let the machine sit in the correct temperature range for a few hours before turning on, and the machine has been in that room for nearly a full 24 hours, so I am guessing it was thrown out for a few reasons, including that the temperature sensor does not work, not to mention how old the unit it. I would hope that there have been some advances in medical X-ray technology in the past 14 years to warrant the purchase of a new machine. Oh well, time to take it apart and find the sensor.
http://http://archive.hak8or.com/pictures/Xray_Teardown/P1260111.JPG A quick google does not give me anything on either of those two stickers, but there is not much to see on such an LCD controller board. It probably has a few chips to drive the screen itself, then the main controller that handles the data going in and out, some RAM for the screen, and a flash storage chip for containing the different characters and images. To get a good write up of such a board it would warrant another tear down just for itself. The wire going to the middle of the board that looks glued on is from the very simple rectangular PCB earlier, so I think I am right in thinking that the function of it is for contrast and brightness.
http://http://archive.hak8or.com/pictures/Xray_Teardown/P1260120.JPG And here is where it gets interesting. What you are seeing is the power modules for the entire xray machine. The blue cylinders on the bottom are what I am guessing, smoothing capacitors for the AC to DC rectification. When current demands rise in a rectified load, you need larger smoothing capacitors so when the current is drawn towards the end or beginning of the cycle, it comes from the capacitors which stored current from the middle-ish of the cycle. If you want to learn more, google "smoothing capacitors" for a better explanation, as I know mine sucks quite bad. The cable I am holding goes from somewhere behind the X-ray head to the touchscreen in the front panel.
http://http://archive.hak8or.com/pictures/Xray_Teardown/P1260122.JPG Another angle of the power section of the unit. In the left most side of the picture, you can spot the white and black cables seen earlier, a fuse, and an EMI filter of sorts. These guys are all between the mains and the rectification, always, and since this is a unit that draws so much power (700 watts I believe), the diode bridge must be on some large heat sink for sorts, unless it is attached to the case, which is very dangerous to do.
http://http://archive.hak8or.com/pictures/Xray_Teardown/P1260150.JPG Here is one of the boards seen within the power section of the unit. We see a trimmer potentiometer, a relay rated for 2A at 30V (these boxes shaped like this on a board are almost always relays), and some ICs. They are photodarlingtons, otherwise known as opto-isolators, usually used for isolation between high voltage (mains or primary side of step down power supply), with a line under them indicating the separation of the high voltage and low voltage sides of the board. In this case there is no such line drawn, but usually there is. They are 4N33 made in the year 1997, in the eight week and 42nd week, as shown by the date code 9708 and 9742.
http://http://archive.hak8or.com/pictures/Xray_Teardown/P1260140.JPG The component side of another board, this one being directly connected to one of the power supply boards. It has some really cool test points, with the colors and plastic covers. I wonder why they did it like that and not just what you see today, which is a tiny copper pad used with a "bed of nails", which I think they should have had back then. Also, notice that one of the traces are a right angle instead of thhe usual 45 degree bends we see nowadays. From what I understand, it is due to manufacturing that the bends are like that, specifically with how the enchant eats away at the copper, and if you have such a 90 degree bends the chances of the etching process going bad at the bend are rather high. If interested, here are some Full size closeups of the board, component side. Picture 1 Picture 2 Picture 3
http://http://archive.hak8or.com/pictures/Xray_Teardown/P1260166.JPG The X-ray head is attached the machine using a hex screw, and I only have the long hex screwdrivers, so after quite a bit of mucking around trying to unscrew them in such a small space, I managed to take off the X-ray head. I have to say, the X-ray head is rather heavy, and when you knock on it then it sounds "full". One of my possible explanations, is that in the user manual it says that the X-ray head is oil cooled, with a maximum anode power of 700 watts, so I guess that the X-ray head is an enclosed system, including the liquid cooling, voltage multiplier, and the high voltage transformer. There is a lack of any fins, so I am guessing that the outer metal is a "shell", with the oil flowing near the surface, allowing heat to be released that way. There are no heavily insulated wires, and no tubes going to the X-ray head, so I am guessing that this is the case. My other idea is that it is just really thick metal, but it may be both.
http://http://archive.hak8or.com/pictures/Xray_Teardown/P1260178.JPG Taking off the black metal surrounding the X-ray "area" gives me this. I am guessing the black metal acts as shielding, but I am not sure. Here you can spot the place to put the hand, the finger, and a board with some wires. This is where the X-ray camera resides.
http://http://archive.hak8or.com/pictures/Xray_Teardown/P1260188.JPG A closer look reveals a few logic chips, such as the MM74HC157M, a multiplexor, a MACH211SP, which is a programable logic device, and a LTC1415CSW, which is a 12 bit, 1.25 MSPS ADC, with a parallel data output.
http://http://archive.hak8or.com/pictures/Xray_Teardown/P1260210.JPG After taking off the X-ray "camera", the plate that provides calibration and testing for the X-ray according to the user manual can now be seen. From what I understand, it provides very good contrast against the bone of the finger.
http://http://archive.hak8or.com/pictures/Xray_Teardown/P1260211.JPG The X-ray sensor seems rather simple, but I cannot seem to open it, even after unscrewing the screws holding it together. I am thinking that inside there may be another gas or something like that, hence them gluing it shut after screwing it shut, so before going any further I will ask the awesome people at 4HV for any ideas, and if there is anything dangerous possibly lurking there.
http://http://archive.hak8or.com/pictures/Xray_Teardown/P1260192.JPG After a while it looks like they just put in an entire computer, but to get to out I have to get through this ISA card. Some chips on it that I see are the IDT72403L35SO, a FIFO, a MACH5 CPLD, some relays, a buzzer, speaker, and some logic ICs. The board is attached to the motherboard of the computer with some screws, one of which was behind the speaker, which was attached to the PCB way off center. Off center screw
http://http://archive.hak8or.com/pictures/Xray_Teardown/P1260226.JPG The wiring from the xray head, with some sort of potting material. I would really want to check out the xray head, especially the high voltage components, but before I try to disassemble the X-ray head, I will ask the community at 4hv if there is anything that might pose a risk to anyone.
Off topic: My website is now on github! In case anyone wants to use the same website, but for their own projects, feel free! :) I am going to put all my pictures under a Creative Commons Attribution-ShareAlike 3.0 Unported License, so you are free to do anything you want with them as long as you put them under the same license and credit me as the original author. At least, that is how I understand it works. I also added in descriptions into the supersized jquery plugin, and the ability to move the box around so it does not block stuff of interest behind it, just have to find out why it is very slow when the image is on a big res screen. The code contents will probably be put under the GPL license.
Awesome case is awesome! It looks so clean and clear! Did you really use cnc? I would expect it to be "foggy" on all sides that the CNC interacted with.
Did you design it in a CAD program, or do it by hand? Also, I am very curious as to what is on the top left of the 2nd picture, it looks REALLY interesting. :P
So I have spent most of the time trying to get a new gallery working using webgl and three.js, but three.js puts a limit on texturing an object, that the texture image has to be in a power of two, so 512 pixels, 1024 pixels, or 2048 pixels. I would then have to work with webkit itself instead of a nice framework like three.js, so I will probably do that later over summer. Currently the gallery begins to slow down drastically when there are too much images (20+). So unless I am able to optimize the super sized gallery for more images (I think I can try to cache the images), I will have to work with what I have now.
Anyways, here are two more pictures so you guys can at least find out what it is that I found. I took it apart much more, but I did not get to the actual Xray head as I am not familiar enough with this xray head to feel that I can safely take it apart without risk of potentially dangerous items inside. Though, I am thinking that there is not anything dangerous in it when powered off, as it it is probably just an Xray tube, but I will ask on http://http://4HV.org later to check. More pictures to come later! :)
Open Source Hardware
