I have been using this site for many years now. It has been a huge help for me, so first of all thanks for everything. I almost always find the answers to my questions from previous posts, this is the first time I ask a question myself.
Ok, now to the main point. What is the actual protocol used to drive the PGD pin while sending the hex file to the target pic. I know that I could build a DIY ICSP Programmer from the countless projects found on the web but I truly want to understand the low level of this subject and build my own ICSP programmer for the sake of learning.
Some more details:
(Just to give you more info about what is on my mind)
The main idea is to use a pic with a USB module (say PIC18F2550) this pic will communicate with a software that sends the hex file to it. After PIC18F2550 stores this hex file (as raw data) in its memory it is going to send it to the target pic (the pic to be programmed) using the "ICSP protocol" (the thing I am looking for).
This link has the Programming Specification ( protocol ) for the chip family you want
Microchip Programming Specification for PIC18F2550 Family
Related
Are there any tips for reading source code samples from manufacturer of MCUs'.
I am a newbie for mcu programming, currently I have a MCU, datasheet and sample codes for them. But problem is sample codes are seems written for experienced users. Too many questions about why they initialized RS232, why they set 4th bit of port 1 and etc.,
Do you have a tips for reading or links where can I get info about how to read datasheets and sample codes of MCU?
I guess experience is the only answer I can give. Just like with programming in general, with time you acquire experience as well as learn buzz words and concepts. With microcontrollers you learn to read datasheets, schematics, etc. Learn about open drain, open collector, weak pull ups, etc. And for serial ports for some reason they are always overcomplicated. The hardest part with microcontrollers and the serial port is usually figuring out what to program to get the right clock divisors, some microcontroller serial ports are straight forward, others are overly complicated, some docs are good some docs are bad, etc.
Another answer is datasheets are always wrong. There are always gaps in the information that you have to hack to figure out. Do not write thousands of lines of code in a vaccuum using only a datasheet, write a small amount of code a few lines to a few dozen, test, and move on, you can get more lines written and debugged in a day when programming from a datasheet than the other path. The datasheets are often not written by the engineers that actually designed the hardware, sometimes it is a junior engineer or a non-engineer. Sometimes the information is simply wrong, sometimes the document is for a different but similar part than the one you have. If they provide software that actually does stuff it is sometimes (not always) more accurate than the datasheet (when I say datasheet assume the users manual, programmers reference manual, whatever the vendor calls the doc with the registers, addressses, and bit definitions for the hardware).
With time and experience you may find, if you take a wide enough view, that some vendors tend to do a better job at providing information to users, others do not, some bury the secrets in libraries, sometimes in binary form and not source. Sometimes the secrets are buried in compilers and other tools they provide (well that is back to apis and libraries). I tend to blacklist such companies, but sometimes you cant always. ARM for example does a very good job of providing the information. the problem is they have so many cores with a number of options each, that are very similar in nature (support the same instruction sets) that it can be difficult to sort through what the one processor you are using that moment does and does not from the docs. Atmel, something about atmel that is hard to put a finger on, the docs are generally well above par, but more than that something about atmel makes them popular with the customers. You will never see an arduino like following, culture, pick a word, with a microchip pic for example. There are a lot of pic followers but it is not like the atmel world (which was there well before the arduino thing happened).
Another note, you might not understand with a single example program and single datasheet the history of a product, there might be code that has been used for a number of chip generations, and there might for example be a bit that is required by an older chip or newer chip and to share the same code that bit is manipulated. that bit might make sense looking at one datasheet and no sense looking at another. this is where hacking comes, in try it without, see what happens. maybe study other parts in the family that this code is said to support it might make more sense.
google is your friend or whatever favorite search engine, find as much open source code and other items for the particular device or whatever. At this level hacking is required, I dont use that term in the bad sense, hacking in the sense that you have to try some of the bits documented in the datasheet, see if that actually works, if not then see what it does if possible, look at other source code and see from that if you can figure it out. Just like there is no perfect car that gets infinite miles per gallon, completely safe, lasts forever, and is inexpensive, there is no perfect chip with the perfect datasheet and sample code. If you want to work at this software/hardware level you have to get your hands dirty, have to not be afraid to let some smoke out of the chips (there is a finite amount of smoke in a chip if you let even a little bit out it wont work), etc.
If the reason you wont ask specifically about the mcu or register you are working with is because it is closed source products or behind an NDA then you probably have access to the company that makes that product and you should be able to get support from them. Usually better support than you would get from a company that you dont have to sign an NDA for. Not that open document, open source companies are bad, just that if the company you buy from is interested in you to the point of showing internally protected information they are interested enough to give you better access to the real engineers that made/know the product. If this is not the case and you are able to talk about it, dont be afraid to just post a question to SO about the register and bits you are wondering about.
Sample code and flow charts in the MCU datasheets are good starting point to initialize a specific peripheral (like RS232).
You just start from there, and track the bit information and what it does, in MCU datasheet.
i am working on a project that uses qr code to check in guest at an event. i intended to implement it as a mobile app on android but my professor require a hardware element to the project. so my question s are
can i do decoding of a qr-code image on a microcontroller with a CMOS camera and which one is recommended?
if not, is it possible to use a cmos camera with a microcontroller to take the picture and send it to a pc to do the decoding and which microcontroller is recommended?
any other suggestion will be appreciated
I wouldn't try to decode QR Code with something less powerful than ARM.
Ad 1.
Of course you can, but, as I said, I wouldn't try on something less powerful than ARM (unless you're a C ninja and you can fit into, say, AVR for this task).
Decoding QR code itself isn't that hard and I you'll be able to write it by yourself (or use existing library).
Ad 2.
You'll need some connectivity to do that. There are many Bluetooth, Ethernet and WLAN boards around (in my experience, best choice may be Bluetooth, you may get away without implementing network stack).
Useful link.
Decoding QR codes is relatively easy as barcodes go. You can use source code from the ZXing library, running on the server side (it's primarily Java) to do the decoding. Decoding is "fast"; on the original Android (ARM7) devices it would still decode in about 100ms.
But I think your question is about image quality. I am not familiar with the output of CMOS sensors, but for QR codes, you don't need color data and you don't need much resolution (240x240 works for most QR codes). If anything the issue is focus.
All right, let me preface this by saying: I'm not completely confident this is programming-related. I'm trying to use software to solve a problem, but the software I actually trust; I suspect I'm doing something wrong with the hardware. However, I don't know where else to ask this question. Superuser already shot me down, and the Gadgets FAQ makes me think it's not a good fit there, either. If this question really strikes you as too off-topic to permit here, do what you gotta do. But, please. If you could go either way, I beg for your mercy.
I have a Pioneer DVD-V5000 player that I'm trying to control via 9-pin RS-232 port. (As opposed to the 15-pin port that's hard to find cables for.) Trouble is, I can't get the thing to acknowledge any commands. I'm not even getting any error messages back; only silence.
I have the specs for communicating with that port in front of me, and as far as I can tell I'm doing everything right; I'm sending two-character ASCII commands followed by a <CR>. I've gone into the Advanced Setup menu on the player, and have selected the 9-pin port (factory default is the 15-pin). The spec seems to be indicating the 9-pin port is perfectly standard; I don't see any indication I need some kind of custom cable to be using it. And I'm following all the setup protocols from the spec: 8-bit data length, 1-bit stop bit, no parity. Baud rate can be either 9600 or 19200, depending on the Advanced Setup, but neither works.
I'm fairly sure the software handling the COM-port communication isn't the problem. I've used a version of this software to successfully control another device, and I'm getting identical results (no response whatsoever) when I try to manually shove through commands with a serial port terminal.
Is there anybody familiar with Pioneer's serial-controlled electronics who can give me some suggestions about where I'm going wrong, or for other avenues of investigation?
For the sake of anybody else in a similar bind who stumbles across this question, I'll swallow my pride and record the correct solution, rather than just delete this into oblivion and pretend I was never this dumb. (Topicality hawks, I'm now far less worried about you nuking this thing.) The solution is unrelated to the specific hardware. It's all about the RS-232 cables and what NOT to do with them.
Specifically, if the F-F cable you have is too short, do not use a M-F cable as an extender -- or, if you do, use two of them. Regardless, your total number of cables MUST BE odd. What's Pin 2 on one end is supposed to be Pin 3 on the other end -- but if you have an even number of cables, then Pin 2 on one end goes to Pin 2 on the other end. This is wrong, and whatever gadget you're trying to talk to will rightfully ignore you. You will get very frustrated, fruitlessly Google away trying to figure out what you did wrong, and post lengthy questions of dubious topicality on your favorite Q&A site.
And seriously, who needs that?
I would like to solder a microcontroller, control buttons and an DVI/HDMI output and program this in a way, that I can store images on it and let them display as a dia-show via the outputs.
It doesn't have to have a lot of storage capacity, 128Mb would be enough.
but I don't know how to start, because I haven't done anything like this before.
My aim is to present some important images to friends by just taking this hardware, connecting it to a TV screen and showing these photos. If should be able to switch the photos manually (using a button) or automatically in a dia-show.
It should support several TV resolutions and it should be connectable to my PC (USB prefered), so that I can upload and delete photos.
So where to start and how to do that?
Thank you in advance, Andreas
If your aim is just to show some photos, there are assuredly simpler and more cost effective ways to do so; devices exist which do more or less exactly what you are proposing.
If your aim is to learn about microcontrollers and this is a project your are taking up to further that, I would recommend looking into the Arduino: http://www.arduino.cc/ or a similar kit based micro, and growing your project from that.
Microcontroller + low level language will be a huge pain to work with, particularly if you wish to handle various file formats and screen resolutions. Get a full-blown computer with an OS instead - something like http://en.wikipedia.org/wiki/PC/104
If your goal is purely to be able to display photos then I would recommend using a digital camera with video out capabilities.
If your aim is to learn about electronics and microcontrollers I would start with a good book and an Arduino board. Note that writing microcontroller code to handle file systems, image formats and video output is non-trivial. Simpler projects may be a better starting point as they are more accessible resulting in quicker progress, less frustration and more motivation!
The engineering field is a interesting field. You can start with the web site "www.microchip.com". You will need a high end device consider the PIC32MX795L512, there is a nice starter kit for it, "Ethernet Starter Kit" http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=2615&dDocName=en545713. This kit has the on board debugger & programmer to do all the hard work.
You get sample projects with the package, you can program using ansi c programming.
IDE : MPLAB which is free, and the C32 compiler has a student/lite version.
Arduino also has a board with the same device.
I personally like "www.techtoys.com.hk", they have device compatible with Microchip boards like techtoys.com.hk/PIC_boards/PIC32STK%20SSD1963%20EVK/PIC32STK%20SSD1963%20EVK%20R1A.htm, or this techtoys.com.hk/PIC_boards/PIC2432EVK-RD4/PIC2432%20EVK%20RD4.htm where this board you will need a debugger/programmer like the low cost PIC Kit 3 "microchip.com/pickit3".
The trouble is you need to write the HDMI video library yourself, there are some VGA libraries available but they are only black and white and very hard to get color with these analog images. The rest of the libraries are already there, USB MSD(flash drive), SD Card, pictures (jpg) etc.
microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=2680&dDocName=en547784
Feel free to contact me if you need some help, I might be able to help with the HDMI library.
It's a lot of fun to play with these toys.
Regards
Lucas
B-Eng Digital Engineering.
imlucanio#yahoo.com (no spamming)
Remember to add the http and www to the web links.
It sounds like you want an iPod. That is a dead simple thing to work with and it does everything you want. Otherwise, very complicated. I'd suggest the BeagleBoard and embedded Linux. Yes, it warrants that level of complexity.
The options for small microcontrollers just aren't there. The Arduino is very popular and yes, you can interface an SD card to it. That'd be your storage. Yes, you can put a digital potentiometer on it, that can be your interface. I've seen some video overlays that do simple text, but never any JPEG display (too much processing required). And certainly no 24 bit color (so that the output would actually look good) - that would take WAY too many pins to do correctly (and the Arduino doesn't have a D/A converter! You'd have to rig something up that would suck). And even then, all of the options for TV out weren't HDMI, but RCA (the old red/white/yellow cables).
So in short, no. Get a computer. That's what can do the job.
Besides Arduino, what other ways are there to learn hardware programming in a hands-on way? Are there any nifty kits available, either a pre-assembled robot, that you can program to move a certain way, or do certain things, or anything similar to that?
Atmel AVR and the PIC both have experiment boards that you can use solder stuff on to, usually they have a couple of buttons and some lights pre-soldered to the area. This let's you program/flash the microprocessor and play with the output pins. You can either write the programs in assembly or C.
Parallax have a number of kits. They have two product lines suited for "playing around", Basic Stamp and something called Propeller. The former is a small microprocessor that runs programs written in Basic (a tad disgusting ;)) and the latter runs something called Spin or assembly (well after compilation obviously.)
I would go with either AVR or the PIC. I've done PIC but I've heard good things about AVR, they seem to ship with better software.
At first look Microsoft's VPL sounds good, but when it comes to actually LEARNING how hardware works it goes a LONG way to hide those details from you. As a matter of fact it is pretty much designed for people who don't program, and is distastful to someone who's actually written embedded software. IF you just want to make stuff happen and not delve into the details it's fine, but if you want to get down to the metal like programming the "Arduino" boards it's not for you.
If you're used to something like the Arduino then something like the PIC will be an easy transistion. SparcFun Electronics has all sorts of DIY type projects and hardware available. If you have a decent bookstore around your area, I would suggest looking for "Circuit Cellar" magazine. It has articles on a monthly basis with project for someone looking to get into hardware projects, everything from homebrew Software Defined Radio to FPGA based 3D graphics. (Raytracing actually) Usually the authors describe the project in an article and "WHY" they made the decisions they did, a description and schematics of the hardware and provide a link to source code.
Cypress Semiconductor has one of the most interesting embedded processors on the market and several high quality dev boards for sale. The PSoC includes the ability to not only configure the software, but also to "drop in" software configured hardware such Analog to digital converters, serial I/O, Digital to Analog and Various amps and filters. It's a REALLY cool concept, and the "touch sensor" capability of the PSoC were actually used in several models of the IPod.
One thing about programming these little micros is they don't have a lot between you and the hardware, you get to see how things really work. It doesn't matter whether you're talking about an 8-bit microcontroller or a quad-core Pentium programming hardware is largely the same concept. You write to a memory mapped register for some piece of hardware like a serial controller, and the hardware responds in someway. If you program a baudrate generator in a PIC or PC it's largely the same idea, you write a value that will be used as a division factor from a given clock to achive a given baudrate. The numbers and names maybe different, but the concepts is the same. On a PC you may have to map to the PCI address of the card, which adds a some complications, but if you looked underneath the OS you would see that that was done just by writing values to registers simalar to programming a PIC to use a different "Page" of memory. Is it worth learning an 8-bitter? Well, there are approximately $5 billion dollars in sales of the little 8-bit micros today with projection only showing growth in that market in the future. I saw one reference that state the average car has 25 Microcontrollers in it. That's not too bad.
I haven't played with it much, but the iRobot looks pretty cool.
The ability to simulate how your robot will work which some of the other answers mentioned is nice, but there's nothing like seeing a real-life robot do what you programmed it to do. That, to me, is what really makes robots fun and cool.
There's the .NET Micro Framework.
It's incredibly simple to use/setup and there's lots of hardware being made to target this framework.
You should take a look at Microsoft Robotics Developer Studio which supports many different kits.
I have always been curious about gumstix. It seems more professional than arduino, and it aims at the Linux programmer. I cannot give you a real suggestion, as I've never played with it, but I would definitely go with one of this toys if I had to do and learn some cool hardware programming.