Рейтинг: 4.5/5.0 (1880 проголосовавших)Категория: Windows: Фото
This document is not currently maintained as PICS has been superseded by the Protocol for Web Description Resources (POWDER ). W3C encourages authors and implementors to refer to POWDER (or its successor) rather than PICS when developing systems to describe Web content or agents to act on those descriptions. A brief document outlining the advantages offered by POWDER compared with PICS is available separately. The Current Status Page lists the PICS Recommendations and in each case includes a link to the document that supersedes it.
Contact details of the individuals named below and links to other documents may no longer be active.
The PICS TM specification enables labels (metadata) to be associated with Internet content. It was originally designed to help parents and teachers control what children access on the Internet, but it also facilitates other uses for labels, including code signing and privacy. The PICS platform is one on which other rating services and filtering software have been built.
No screenshots, No pictures with added/superimposed text. This includes image macros. comics, infographics and most diagrams. Text (e.g. a URL) serving to credit the original author is exempt.
No porn or gore. NSFW content must be tagged.
No personal information. This includes anything hosted on Facebook's servers, as they can be traced to the original account holder. Stalking & harassment will not be tolerated. No missing-persons requests!
No post titles soliciting votes (e.g. "upvote this").
No DAE, "[FIXED]" or "cake day" posts, nor posts addressed to a specific redditor. "[FIXED]" posts should be added as a comment to the original image.
Submissions must link directly to a specific image file or to a website with minimal ads. We do not allow blog hosting of images ("blogspam"), but links to albums on image hosting websites are okay. URL shorteners are prohibited.
Please be civil when commenting. Racist/sexist/homophobic comments and personal attacks against other redditors do not belong here.
If your submission appears to be filtered, but definitely meets the above rules, please send us a message with a link to the comments section of your post (not a direct link to the image). Don't delete it as that just makes the filter hate you!
If you come across any rule violations please report the submission or message the mods and one of us will remove it!
Please note: serial reposters may be filtered
Please also try to come up with original post titles. Submissions that use certain cliches/memes will be automatically tagged with a warning.
If your post doesn't meet the above rules, consider submitting it on one of these other subreddits:
Arguably, Microchip’s PIC microcontrollers do not get enough posts here. One of the drawbacks for some of us is that Linux support for PICs is not very well known. The information is out there, but no one has laid out the process of going from writing C code to programming a chip. Written for Linux users that are familiar with microcontrollers, basic circuits, the C programming language, and can read a datasheet, this how-to should get you up and programming a PIC quickly with Linux.
The Compiler:
The Small Device C Compiler. sdcc is what will be used to create the .hex file needed to program a PIC. Support for PICs is still growing, and still in beta, so be aware that things outside the code and chips of this article may need some debugging. However, like every other open source project out there, more contributing users will help the project. Best of all, it is free, with ports to Windows and MacOS X, this is a compiler that handles many architectures and devices without the program limit of free versions of for-pay compilers that are limited to Windows. Sdcc is available through various distributions’ package managers including Ubuntu and Fedora.
To install sdcc on Ubuntu:
To install sdcc on Fedora:
Three different PIC chips were used in the writing of this tutorial: the 40 pin PIC16F887. the 14 pin PIC16F688. and the 8 pin PIC12F675. You can follow along with any of these chips as well as other chips.
The Programmer:
We will be using two programmers, Olimex’s PICStart+ compatible PIC-MCP-USB programmer, and Microchip’s PICkit 2. Both programmers have been tested to work with the three chips used here.
The PICStart+ programmers use the picp program. Most any PICStart+ compatible programmer will work with picp. Easily installed in Ubuntu with:
For Fedora and other distributions may have to download and install it from source. So, in an empty directory of your choosing:
The source is on [Jeff Post]’s Development Tools for PIC programmers page along with other programming options.
If you will be using the PIC16F887 and picp, you will need to modify your /etc/picp/picdevrc file by adding the following lines:
The above lines are modified parameters for PIC16F886 found in a post by [Al Williams]. For chips not already in /etc/picp/picdevrc, additional parameters will need to be added to /etc/picp/picdevrc.
PICkit 2 programmers will work with another program called pk2cmd hosted by Microchip here. You will need to install pk2cmd from source. so in a directory of your choosing:
Note that Microchip touts the PICkit 3 as a replacement for the PICkit 2. It is not a replacement for the PICkit 2 as there are no Linux drivers for the PICkit 3, so do not buy the PICkit 3 thinking it will work in Linux.
There is also another program that claims to work with a range of DIY PIC programmers: PICPgm. We have not tried this program or any of the DIY programmers at this point. We know there are other PIC programmers out there, both cheap and expensive, that have not been mentioned. Perhaps a PIC programmer roundup is in need of writing.
The code for this how-to is a kind of hello world program using LEDs. The code for this is hosted on Github, you can follow along with the blink.c file for the PIC16F887. PIC16F688. or PIC12F675. Also included are working .hex files. Here is the PIC16F887 code as a reference as we walk through each major operation:
The first line is the #include for the header file of the particular chip you will be using. It tells the compiler which registers are available and where they are located in memory. In most systems, the header files will be in /usr/share/sdcc/include.
Then we setup the configuration word or words fuses. They are only able to be written when the chip is programmed, but we can define them here so we don’t have to manually program them later. The PIC16F887 has the address for the configuration words defined in its header file as _CONFIG1 and _CONFIG2. The PIC16F688 and PIC12F675 do not have the configuration word address defined in their header (we said sdcc was in beta, didn’t we?), so we just use the address of the configuration word: 0x2007. The configuration words are specific to the chip model and application and are described in the chapter “Special Features of the CPU” in each of the respective chips’ datasheets. In the blink.c samples, the configuration word is just a 16bit hexadecimal word, but the word can be made more human readable by ANDing together the configuration options. Check out the chips’ header files for the names of the options.
Next, we setup some global variables, one for the value that will be output on the LEDs and the other for a delay counter.
In the void main(), we set the PORTC tristate register, TRISC to all outputs. The PIC12F675 has only one port, GPIO, and its tristate register is TRISIO. After setting the tristate register, we enter an infinite loop with while(1). Inside that loop is a delay loop so that we can see the LEDs changing. Following the delay loop, the display counter is incremented and then written to PORTC (or GPIO) for display on the LEDs.
Compiling the Code:
Now that we have reviewed the code, it is time to turn it into something a PIC can use. sdcc will take the blink.c file and make a bunch of files. One of these files will be blink.hex which will be what the PIC device programmer will be writing to the PIC. Here’s how:
For the PIC16F887:
For the PIC16F688:
For the PIC12F675:
The -mpic14 option tells sdcc that it will be compiling for the 14-bit instructions of the PIC16 and PIC12 families. The second option is the specific chip that code will be compiled for. The last thing on the line is the file containing the C code that will be compiled.
Programming the Chip:
To program a chip you will take your device programmer and connect the chip you want to load with your program. Unless you are using a socket programmer like the PIC-MCP-USB, you will need to consult the datasheets of the programmer and the chip to be programmed for the proper connection. Once properly connected, you will need to run the program to run the programmer:
For a PICStart+ programmer on /dev/ttyUSB0 programming a PIC16F887 :
For a PICkit 2 programmer programming a PIC16F887:
If you are programming another chip, or the PICStart+ programmer is on a port besides /dev/ttyUSB0, you will need to make corresponding changes to the commands.
Note: The code provided for the PIC16F887 disables low-voltage programming. Some of the programmers available but not directly mentioned only perform low-voltage programming. If you have one of these programmers, you will need to change the code so that the low-voltage programming bit in the configuration words allows for low-voltage programming. The low-voltage programming pin on the microcontroller will also need to be pulled low during normal operation.
Wire the Circuit:
The circuit for this project with the code provided is really simple to breadboard. Below are the schematics for the three chips:
Start out by connecting the Vdd pins to a positive voltage source between 4.5 volts and 6 volts and the Vss pin to ground. The 40 pin PIC16F887 and the 14 pin PIC16F688 will both need a pullup resistor on their master clear pin. To any one or all of the PORTC pins (or GPIO pins for the PIC12F675), connect LEDs with current-limiting resistors to ground. Note that pin 4 of the PIC12F675 is only an input and will not light an LED. The current out of any pin of the three chips used is limited to 20mA, so the current-limiting resistors are optional for most cheap jellybean LEDs. What you should see when you power up the circuit are blinking LEDs. The LEDs should be lighting to a binary count.
Your turn!
Now that we have given you a start with programming PICs using Linux, we hope to see more projects using these chips and the tools we have mentioned above. Though this article was written for Linux users, Windows and MacOS X users should be able to use sdcc for their PIC programming needs.
Image information: The Tux logo is by Larry Ewing, Simon Budig, and Anja Gerwinski, via Wikimedia Commons. The Microchip logo is a registered trademark of Microchip Technology Incorporated .
PICS — or pics may refer to: *Planetary Image Cartography System of the USGS *Platform for Internet Content Selection, a content rating specification for websites *Punjab Institute of Computer Science *Protocol Implementation Conformance Statement… … Wikipedia
PICS — abbr. platform for Internet content selection. * * * … Universalium
PICS — [Abk. fur Platform for Internet Content Selection, dt. »Forum fur Inhaltsauswahl im Internet«], eine unter der Schirmherrschaft des World Wide Web Consortiums (W3C) 1995 ins Leben gerufene Initiative von Internetdienstanbietern (ISPs) und Hard… … Universal-Lexikon
PICS — Platform for Internet Content Selection (engl. Abk. PICS, deutsch etwa: Plattform zur Auswahl von Internetinhalten) ist ein Standard des World Wide Web Consortium, der dazu dienen soll, den Inhalt von Webseiten zu bewerten. Die PICS Label werden … Deutsch Wikipedia
pics — olym·pics; pics; para·lym·pics; … English syllables
PICS — ? >en sg. >COP>INTERNET Platform for Internet Content Selection. Norme permettant d indiquer la teneur d un site sur le Net (C est gore? Y a du Q?). Comme vous n etiez pas deja assez pervers, on vous donne la possibilite de vous autocensurer.… … Dictionnaire d'informatique francophone
PICS — Programme International de Cooperation Scientifique. Des PICS sont frequemment inities par le CNRS … Sigles et Acronymes francais
pics — geniniai statusas T sritis zoologija | vardynas atitikmenys: lot. Picidae angl. woodpeckers vok. Spechte rus. настоящие дятловые pranc. picides; pics rysiai: platesnis terminas – geniniai pauksciai siauresnis terminas – geneliai siauresnis… … Pauksciu pavadinimu zodynas
PICS — Platform For Internet Content Selection (Computing » Networking) *** Protocol Implementation Conformance Statement (Governmental » US Government) * Platform for Internet Content System (Computing » Hardware) * Punjab Institute of Computer Science … Abbreviations dictionary
PICS — Pacing in Cardiomyopathy Study … Medical dictionary
PICS — • Protocol Implementation Conformance Statement/Standard (unter 1.)) • Plug in Inventory Control System Betriebssystem(teil) im NCIH • Platform for Internet Content Selection (W3C) • Photo Index & Cataloging System NASA • Payload Integrated… … Acronyms
Needs better formatting, etc
Manufactured by Microchip, the PIC ("Programmable Intelligent Computer" or "Peripheral Interface Controller" ) microcontroller is popular among engineers and hobbyists alike. PIC microcontrollers come in a variety of "flavors", each with different components and capabilities.
Many types of electronic projects can be constructed easily with the PIC family of microprocessors, among them clocks, very simple video games, robots, servo controllers, and many more. The PIC is a very general purpose microcontroller that can come with many different options, for very reasonable prices.
History EditGeneral Instruments produced a chip called the PIC1650, described as a Programmable Intelligent Computer. This chip is the mother of all PIC chips, functionally close to the current 16C54. It was intended as a peripheral for their CP1600 microprocessor. Maybe that is why most people think PIC stands for Peripheral Interface Controller. Microchip has never used PIC as an abbreviation, just as PIC. And recently Microchip has started calling its PICs microcontrollers PICmicro MCU's.
How do you find a PIC that is right for you out of nearly 2000 different models of PIC microcontrollers?
The Microchip website has an excellent Product Selector Tool. You simply enter your minimum requirements and optionally desired requirements, and the resulting part numbers are displayed with the basic features listed.
You can buy your PIC processors directly from Microchip Direct. Microchip's online store. Pricing is the same or sometimes better than many distributors.
Rule Number 1: only pick a microprocessor you can actually obtain. PICs are all similar, and therefore you don't need to be too picky about which model to use.
If there is only 1 kind of PIC available in your school storeroom, use it. If you order from a company such as Newark or DigiKey. ignore any part that is "out of stock" -- only order parts that are "in stock". This will save you lots of time in creating your project.
Recommended "first PIC" EditAt one time, the PIC16F84 was far and away the best PIC for hobbyists. But Microchip, Parallax, and Holtek are now manufacturing many chips that are even better and often even cheaper, because of the higher level of production.
PIC: Select a chip and buy one .
Many people recommend the following PICs as a good choice for the "first PIC" for a hobbyist, take in count the revision numbers (like the A in 16F628A):
Of the many new parts Microchip has introduced since 2003, are any of them significantly better for hobbyists in some way than these chips ? Todo: Does "Starting out PIC Programming: What would be a good PIC chip to start out with?" have any useful recommendations to add to the above?
There are several different "families":
More selection tips EditEach family has one "full" member with all the goodies and a subset of variant members that lack one thing or another. For example, on the 16F84 family, the 16F84 was the fully featured PIC, with Flash memory and twice the program space of the 16F83. The family was also composed by the 16C84 and 16C83, one of the few reprogrammable C suffix PICs. For prototyping, we generally use the "full" version to make sure we can get the prototype working at all. During prototyping we want to tweak code, reprogram, and test, over and over until it works. So we use one of the above "Flash" families, not the "OTP" families, unless required. For short production, the C parts are recommended. For very long production lines some PICs with mask-programmed ROMs where used. Now in-factory preprogramming is available from Microchip.
Each member of each family generally comes in several different packages. Hobbyists generally use the plastic dual inline package (often called DIP or PDIP) because it's the easiest to stick in a solderless breadboard and tinker with. (The "wide-DIP" works just as well). They avoid using ceramic dual inline package (CDIP), not because ceramic is bad (it's just as easy to plug into a solderless breadboard), but because the plastic parts work just as well and are much cheaper.
(Later, for mass production, we may figure out which is the cheapest cut-down version that just barely has enough goodies to work, and comes in the cheapest package that has just barely enough pins for this particular application . perhaps even a OTP chip ).
And then each different package, for each member of each family, comes in both a "commercial temperature range" and a "industrial temperature range".
PIC 16x EditThe PIC 16 family is considered to be a good, general purpose family of PICs. PIC 16s generally have 3 output ports to work with. Here are some models in this family that were once common:
Many programs written for the PIC16x family are available for free on the Internet.
Flash-based chips such as the PIC16F88 are far more convenient to develop on, and can run code written for the above chips with little or no changes.
PIC 12x EditThe PIC12x series is the smallest series with 8 pins and up to 6 available I/O pins. These are used when space and/or cost is a factor.
PIC 18x EditThe PIC 18x series are available in a 28 and 40-pin DIP package. They have more ports, more ADC, etc. PIC 18s are generally considered to be very high-end microcontrollers, and are even sometimes called full-fledged CPUs.
Microchip is currently (as of 2007) producing 6 Flash microcontrollers with a USB interface. All are in the PIC18Fx family. (The 28 pin PIC18F2450, PIC18F2455, PIC18F2550; and the 40/44 pin PIC18F4450, PIC18F4455, PIC18F4550 ).
The PIC Stack EditThe PIC stack is a dedicated bank of registers (separate from programmer-accessible registers) that can only be used to store return addresses during a function call (or interrupt).
Many algorithms involving pushing data to, then later pulling data from, some sort of stack. People who program such algorithms on the PIC must use a separate software stack for data (reminiscent of Forth ). (People who use other microprocessors often share a single stack for both subroutine return addresses and this "stack data").
Call-tree analysis can be used to find the deepest possible subroutine nesting used by a program. (Unless the program uses w:recursion ). As long as the deepest possible nesting of the "main" program, plus the deepest possible nesting of the interrupt routines, give a total sum less than the size of the stack of the microcontroller it runs on, then everything works fine. Some compilers automatically do such call-tree analysis, and if the hardware stack is insufficient, the compiler automatically switches over to using a "software stack". Assembly-language programmers are forced to do such analysis by hand.
What else do you need Edit Compilers, Assemblers EditVersions of BASIC, C, Forth, and a few other programming languages are available for PICmicros. See Embedded Systems/PIC Programming .
downloaders EditYou need a device called a "downloader" to transfer compiled programs from your PC and burn them into the microcontroller. (Unfortunately "programming" has 2 meanings -- see Embedded_Systems/Terminology#programming ).)
There are 2 styles of downloaders. If you have your PIC in your system and you want to change the software,
An (incomplete) list of programmers includes:
Many people prefer to use a "bootloader" for programming whenever possible. Bootloaders are covered in detail in chapter Bootloaders and Bootsectors .
Power Supply EditThe most important part of any electronic circuit is the power supply. The PIC programmer requires a +5 volt and a +13 volt regulated power supply. The need for two power supplies is due to the different programming algorithms:
This is already taken care of inside the PIC burner hardware. If you are curious as to how this is done, you might want to look at the various PIC burner hardware schematics online. [1] [2]
Pin Diagrams Edit Oscillator Circuits EditNot all the PIC microcontrollers have built-in RC oscillator circuits available, although they are slow, and have high granularity. External oscillator circuits may be applied as well, up to a maximum frequency of 20MHz. PIC instructions require 4 clock cycles for each machine instruction cycle, and therefore can run at a maximum effective rate of 5MHz. However, certain PICs have a PLL (phase locked loop) multiplier built in. The user can enable the Times 4 multiplier, thus yielding a virtual oscillator frequency of 4 X External Oscillator. For example, with a maximum allowable oscillator of 16MHz, the virtual oscillator runs at 64MHz. Thus, the PIC will perform 64 / 4 = 16 MIPS (million instructions per second). Certain pics also have built-in oscillators, usually 4Mhz for precisely 1MIPS, or a low-power imprecise 48kHz. This frees up to two I/O pins for other purposes. The pins can also be used to produce a frequency if you want to synchronize other hardware to the same clock as one PIC's internal one.
Response.PICS (МеткаPICS )
Строка, которая является правильно отформатированной меткой PICS. Значение, указанное параметром PICSLabel. будет добавлено к заголовку метки PICS
Для файла .asp, который содержит
Response.PICS("(PICS-1.1 <http://www.rsac.org/ratingv01.html> labels on " & chr(34) & "1997.01.05T08:15-0500" & chr(34) & " until" & chr(34) & "1999.12.31T23:59-0000" & chr(34) & " ratings (v 0 s 0 l 0 n 0))")
следующий заголовок будет добавлен:
PICS-label:(PICS-1.1 <http://www.rsac.org/ratingv01.html> labels on "1997.01.05T08:15-0500" until "1999.12.31T23:59-0000" ratings (v 0 s 0 l 0 n 0))
ПримечанияСвойство PICS вставляет строку в заголовок, независимо от корректоности метки PICS.
Если страница содержит несколько тегов, включающих Response.PICS. каждый экземпляр будет заменять метку PICS, установленную предыдущим экземпляром. В результате метка PICS будет установлена в значение, указанное последним экземпляром Response.PICS на странице.
Поскольку метка PICS содержит кавычки, каждая из них должна быть заменена на " & chr(34) & " .
Что такое Хостинг картинок Firepic.org? Как его использовать?
Это бесплатный хостинг изображений. Мы предназначены для того, чтобы поделиться своими цифровыми фотографиями с друзьями и семьей, по электронной почте, добавлять изображения к сообщениям на форумах, социальных сетях, блогах и онлайн-аукционах..
Сколько стоит услуга?
Этот веб-сайт всегда будет 100 процентов бесплатен Хостинг картинок Firepic.org поддерживается нашими рекламодателями..
Какие форматы файлов изображений поддерживаються?
PNG, JPG, JPEG, GIF изображения и фотографии могут быть загружены с условием предоставления наших услуг.
Какие фотографии вы будете размещать для меня?
Наш сервис будет принимать любые юридически разрешенные изображения, за исключением непристойных. Подробнее - в правилах
Разрешены ли пямые ссылки?
Да, мы позволяем "прямые ссылки". Для эскизов, ведущих к большому изображению.
Как долго вы будете хранить мои изображения?
Возникновение каких-либо непредвиденных событий. Загруженные изображения, которые не нарушают наши правила хранятся на нашем сервере вечно! Однако, если ваше изображениене не было открыто более чем 60 дней, оно будет автоматически удалено с нашего сервера.
Какой максимальный размер изображения?
Максимальный размер изображения 5 MB.
Что я могу сделать, чтобы помочь?
Ссылайтесь на нас с вашей веб-страницы, форума, блога или профиля, и пусть другие знают о нашем сайте!
Есть еще вопросы?
Пожалуйста, пишите на электронную почту администратора.
О фотохостингеFirePic – бесплатный фотохостинг без регистрации для публикации фотографий, картинок и других изображений на форумах, в чатах, блогах и других сайтах сети Интернет.
При помощи FirePic вы можете поделиться интересной картинкой или вашей новой фотографией с друзьями и собеседниками.
Самый быстрый хостинг файлов и изображений позволит не думать о месте на гаджетах и позволит создавать бесплатные галереи фото и делиться ими в любом месте и в любое время.
Отличительная черта фотохостинга FirePic – высокая скорость загрузки при максимально допустимом объеме изображений (до 5 мегабайт).
Сервис хранения картинок полностью бесплатен и не ограничивает время хранения изображений. Ваши фотографии на вечном хранении у нас.
Ваша ссылка - вечна!
Firepic - быстрый и бесплатный хостинг постеров, скриншотов, фото и других изображений для форумов
