http://www.mosaic-industries.com/embedded-systems/ 2013-05-20T14:08:57+00:00 http://www.mosaic-industries.com/embedded-systems/ http://www.mosaic-industries.com/embedded-systems/lib/tpl/mosaic/images/favicon.ico text/html 2013-05-18T01:35:21+00:00 pkc http://www.mosaic-industries.com/embedded-systems/using-the-docweb This documentation web provides detailed specifications, users guides, drawings, sample software, and application assistance for all of Mosaic's embedded computer products. Navigating this web You can navigate this site like any other web site - by following links. You can also quickly browse the site several ways: • In most browsers, you can open a link in a new tab by holding down the either the shift or control key when you click on the link. You can also navigate using your browser by clicking the forward and back buttons, reopening recently closed pages, or bookmarking pages. • Use the colored buttons across the top of this page to go directly to specific product guides. Hovering over the buttons opens a submenu. • Most importantly, you can navigate using a "file explorer" type navigation menu located in the left sidebar. If the left sidebars are not visible, open them by clicking the "open button" at the top left corner of this page. Once opened, the navigation box remains visible from all pages. text/html 2013-05-18T01:34:19+00:00 pkc http://www.mosaic-industries.com/embedded-systems/dokuwiki/help-for-readers/printing Use the print button for a printer-friendly version of a page. "Any of our documentation web pages can be printed on paper or saved as a pdf file. To print you just use your browser's print function, after first setting the "Page Setup" options. You can then print directly to a printer, or you can export the page as a PDF file." How to print Use the printer button on the right side of the page menubar at the top of this page to get a printer friendly version of a page. You can then use your browser's print menu to print the page. If you choose a PDF print driver in the print dialog box you can convert the page to a pdf file. Printing should be as easy as that, but if you have any problems, here are a few suggestions: There's a bug in the print dialog box of many Windows applications, including Firefox. The bug is this: the scaling and margins of the "Page Setup" text/html 2013-05-18T01:32:54+00:00 pkc http://www.mosaic-industries.com/embedded-systems/dokuwiki/help-for-readers/microcontroller Navigating, printing and searching this Documentation Web This web site is organized by product. In the left pane navigation menu you'll find folders for product categories, that contain folders for individual products. Clicking on a folder takes you to an overview page, and clicking on the plus box before the folder shows you the folders/pages within the folder. In general, each product has a users guide, a glossary of programming functions associated with the product or its driver software, and schematics/diagrams. There is also a function summary page that lists all software functions for the product by category. When critical software functions are mentioned in the text of a page, you'll see that they are often highlighted and underlined with a dotted line, like thisFunction(). Clicking on the function name will open a popup box containing its glossary definition, and clicking on a 'More...' text/html 2013-05-18T01:32:15+00:00 pkc http://www.mosaic-industries.com/embedded-systems/dokuwiki/help-for-readers/search Search using the site's search box, or by right-clicking links in the navigation menu. You can search the entire Documentation Web using the Search box at the top right corner of your window. To use it, just type in your search term. You can precede your keywords with "+" to include a word, and, "-" to exclude a word in your query. If you don't use a modifier, "'+'" is assumed. You may search for exact phrases by enclosing them with double quotes. And you can do a partial search by adding a "'*'" wildcard, "e.g." searching for "net" will only find "net", but searching for "*net" will find "internet" as well as "net". In most browsers if you double click in the search box you should also get a drop down list of prior search terms. Once you find the document or page you want, you can find a word or phrase on it by using your browser's search facility (Ctrl-F). text/html 2013-05-18T00:30:58+00:00 pkc http://www.mosaic-industries.com/embedded-systems/dokuwiki/help-for-readers/navigation You can navigate this site like any other web site - by following links. In most browsers you can open a link in a new tab by holding down the control key when you click on the link. You can navigate using your browser by clicking the forward and back buttons, reopening recently closed pages, or bookmarking pages. This Documentation Web also provides a "file explorer" type sidebar for convenient navigation. If you don't see a left column sidebar, open it by clicking the "navigate button" at the top left corner of this page's top menubar. Once opened, the navigation box remains visible from all pages. In the navigation box, the "folders" usually represent a Users Guide for a particular product - clicking on the folder shows an overview of the product and its Users Guide. The "files" shown (also called "pages" or "documents") are like chapters in a book. You can print them to your printer or as a *.pdf document. Further, there's a great search feature, making it easy to find content. text/html 2013-05-17T23:34:58+00:00 pkc http://www.mosaic-industries.com/embedded-systems/dokuwiki/microcontroller [DokuWiki-using-the-Mosaic-Template] DokuWiki is a standards compliant, easy-to-use Wiki, particularly good for creating and maintaining documentation. We use it as the CMS underlying this web site. You can learn more about Dokuwiki from the following sites: • About-Dokuwiki • Download-Dokuwiki • Dokuwiki-manual [Mosaic Dokuwiki Template Dokuwiki is customized using templates. The look and feel of the dokuwiki installation you are viewing, with its three-column liquid-center layout, navigation and link boxes, and customizable regions on the page, is created using the "Mosaic" template. We'll soon make available for download the Mosaic Dokuwiki template so that you may also use it if you wish. Contact-us if you have any questions about our use of Dokuwiki.] [Site Navigation "DocWeb-Home-Page" Mosaic Documentation Web index "Help"] text/html 2013-05-13T23:18:28+00:00 pkc http://www.mosaic-industries.com/embedded-systems/microcontroller-projects/electronic-circuits/push-button-switch-turn-on/inrush-current-limited-mosfet Here are some electronic circuits for controlling the slew rate of a MOSFET switch. Why is that important? Rapidly turning ON power to some devices can compromise their lifetime and reliability owing to large in-rush currents into their input capacitors. In particular, some devices place large tantalum capacitors on their inputs to filter ripple from the input voltage, or to provide switching currents to downstream switch mode power supplies. Suddenly providing voltage to those tantalum capacitors can result in in-rush currents of hundreds or thousands of amperes for a short time, greatly exceeding their in-rush or surge current capability, and sometimes even resulting in a small explosion! Tantalum capacitors are particularly prone to fireworks. A slew rate limited load switch solves this problem. The in-rush current problem is solved by using a MOSFET power switch circuit that slew-rate limits its output. Instead of allowing the switch's output voltage to bounce up to the full supply voltage almost instantaneously, if its rate of increase is limited the maximum current into any downstream … text/html 2013-05-13T19:18:07+00:00 nick http://www.mosaic-industries.com/embedded-systems/sbc-single-board-computers/freescale-hcs12-9s12-c-language/instrument-control/spi-serial-peripheral-interface How to use the SPI for fast, synchronous serial data exchange between the PDQ Board and peripheral devices The Serial Peripheral Interface, SPI, is a fast synchronous serial interface. It provides a convenient means of connecting the PDQ Single Board Computer (SBC) to a variety of peripheral devices, including analog to digital and digital to analog converters, real time clocks, sensors, and actuators. Because the SPI bus is implemented using separate clock, transmit and receive data lines, each communicating device can simultaneously send and receive data over the SPI link. Using the SPI bus for fast serial data exchange The Freescale 9S12 (HCS12) processor includes three synchronous SPI ports named 'SPI0', 'SPI1', and 'SPI2'. 'SPI0' is available for general use, and is brought out to the Wildcard expansion bus. It is also used to interface to the real-time battery-backed clock/calendar on the PDQ Board. text/html 2013-05-10T21:26:02+00:00 pkc http://www.mosaic-industries.com/embedded-systems/microcontroller-projects/raspberry-pi/gpio-pin-electrical-specifications The Raspberry Pi provides general purpose digital input/output pins (called GPIO pins) that you can use for reading digital logic signals or for outputting digital logic levels. The outputs do not have much current capability, but you can drive LEDs or other low current devices. Of course to use them effectively and safely, you need to know their voltage levels and drive capability, and unfortunately, the RPi vendors don't supply the GPIO pin specs. It is a source of frustration to Raspberry Pi users that the electrical characteristics of the input/output pins of the Broadcom BCM2835 SoC (system-on-chip) are not adequately specified in the Raspberry Pi documentation or processor datasheet. This page tries to address that inadequacy by piecing together information from the Raspberry-Pi-foundation, other sites including the eLinux-Wiki, and datasheets of other processors. However, please treat any updated specifications at RaspberryPi.org as definitive. text/html 2013-05-10T20:47:26+00:00 pkc http://www.mosaic-industries.com/embedded-systems/microcontroller-projects/raspberry-pi/on-off-power-controller It would be convenient to use a momentary contact push button switch to turn ON and turn OFF your Raspberry Pi (RPi). A press of a button should apply power to the micro USB header, and keep it ON while the Raspberry Pi initializes and starts its application programs. There should be several options for powering OFF the Raspberry Pi: • The RPi should be able to turn itself OFF fully autonomously, under program control, automatically on an internal timer, or in response to a network signal. • You should be able to initiate a turn OFF sequence by momentarily pressing an OFF button. The Raspberry Pi should then shut down its application program in an orderly way, and turn itself OFF. • If the RPi fails to turn itself OFF or crashes, you should be able to press the button longer to force it OFF. This behavior can be implemented using a latching MOSFET power switch. The latching and toggle ON/OFF power switch circuit for controlling microcontrollers shown here is easily adapted for controlling a Raspberry Pi in this manner. Here's the circuit to use: text/html 2013-05-09T22:19:49+00:00 nick http://www.mosaic-industries.com/embedded-systems/c-ide-software-development/codeblocks-gnu-c-gcc-compiler/c-library-hcs12-9s12/c-functions-rtos Detailed descriptions of all C language functions available to the PDQ Board and the Mosaic IDE Plus Programmers of the PDQ Board single board computer develop their C language application software using the Codeblocks-based Mosaic IDE Plus Integrated Development Environment. The IDE Plus provides a GNU C (GCC) compiler, a full-featured text editor, and a customized terminal program that enables rapid program downloads and interactive debugging of the HCS12/9S12 MCU. The Mosaic IDE Plus software development environment is ideal for embedded systems and RTOS programming. These C library functions can control all the hardware on the PDQ Board, including all features of the Freescale MC9S12 68HCS12 9S12 HCS12 MCU. This glossary defines all the customized C functions that speed programming of the PDQ Board. This glossary is split into three web pages, by alphabetical order (starting with the underscore character): "A-H" text/html 2013-05-09T06:54:47+00:00 pkc http://www.mosaic-industries.com/embedded-systems/sbc-single-board-computers/hcs12-9s12-freescale-development-board/microcontroller-projects The "PDQ Board Lite" embedded design platform hosts extensive analog and digital I/O (input/output), as well as multiple communications lines. This instrument development/prototyping board provides the following I/O and functionality: • 16 lines of 10-bit resolution analog inputs (also configurable in banks of 8 as digital inputs) • 8 lines digital I/O on port T for counter/timer capability or general purpose I/O • 8 lines digital I/O on port P for 8-bit or 16-bit resolution PWM (pulse-width-modulated) or general purpose I/O • 8 lines general purpose digital I/O on Port M • 1 I2C communications port; I2C signals SDA and SCL are pulled up onboard by 4.7K resistors • 2 RS232 serial communications ports. Both normal,full-voltage RS232 and noninverted, logic-level RS232 are available for both serial ports. • 2 SPI ports are available on a 10-pin header. text/html 2013-05-08T05:49:21+00:00 pkc http://www.mosaic-industries.com/embedded-systems/sbc-single-board-computers/hcs12-9s12-freescale-development-board/connector-pinouts The PDQ Board Lite is a low cost HCS12 9S12 single board computer and development platform for instrument control and automation. Numerous headers and connectors provide access to its plentiful I/O and custom prototyping area. The following tables provide the signal pinouts for all headers and connectors on the PDQ Board Lite. The headers are easily identified by designators on the board. Their positions are also shown in the following figure: [Connections-to-the-analog-and-digital-I/O-of-a-9S12/HCS12-development-board] [Fig. 1: Top view of the PDQ Board Lite showing connector placement.] H1: Serial connector H1: Serial Communications Header Signal, Pins, Signal /TxD1, - 1, 2 -, /RxD1 DGND, - 3, 4 -, RxD2 TxD1, - 5, 6 -, RxD1 /TxD2, - 7, 8 -, /RxD2 DGND, - 9, 10 -, TxD2 Note: | This pinout differs from that of the PDQ Board comm header in that RS485 signals are replaced with logic level RS232 signals. text/html 2013-05-03T23:17:04+00:00 pkc http://www.mosaic-industries.com/embedded-systems/microcontroller-projects/raspberry-pi/microcontroller This online documentation (tutorials, application notes and technical specifications) for the Raspberry Pi computer is provided as a public service to the Raspberry Pi community. The RPi is a very useful hobbyist device and a splendid teaching platform for embedded systems. Its strength is that it provides a fully functional networked computer with the advantage of GNU Linux programming, while its limitations are that it has nondeterministic response times and insufficient I/O for most real time control or instrumentation and automation applications. While we would prefer that you use the single board computers that we sell (and please do take a look at our embedded controllers like the PDQ-Board, PDQ-Board-Lite, QCard-Controller and modular-I/O-boards), we also provide the following Raspbery Pi documentation and tools in the hope you find them useful. • Raspberry-Pi-GPIO-Pin-Electrical-Specifications text/html 2013-04-27T08:25:46+00:00 pkc http://www.mosaic-industries.com/embedded-systems/microcontroller [ Here you'll find how-to guides, product manuals and technical specifications for Mosaic's embedded microcontrollers, C language programmable single board computers, embedded device servers, operator interfaces, analog and digital I/O modules, development software, and GNU C compilers and IDEs.] This documentation web provides detailed specifications, users guides, drawings, sample software, and application assistance for all of Mosaic's embedded computer products. If you have a microcontroller project, or are using an embedded SBC for instrumentation or automation, you can find numerous tutorials, manuals and user guides here. The site is organized into separate sections for single board computers, GUI/touchscreen user interfaces and operator interfaces, embedded device servers, C language programming, manuals for I/O boards, application notes, and program examples. Mosaic Documentation Web index text/html 2013-04-26T01:35:18+00:00 pkc http://www.mosaic-industries.com/embedded-systems/instrumentation/conductivity-meter/manual-conductance-measurement The Conductivity Sensing Wildcard is primarily intended to be used in conjunction with the Analog I/O Wildcard and one of our embedded controllers, for example the PDQ Board or QCard Controller. In that case, its output is measured with very high precision and the readings converted into indications of conductivity by embedded software drivers. However, you can also use the Wildcard in stand-alone operation, in which you manually measure its output with a digital volt meter and compute the conductance manually or with the assistance of a spreadsheet. This page describes how you should connect to the Wildcard in that case. Basic Operation The principle of operation of the Conductivity Wildcard is described-here. Briefly, it's a resistive voltage divider, as shown in this-figure, driven by a small AC signal, a 1 volt peak-to-peak square wave at 40 kHz (You may see a frequency of 2 kHz cited elsewhere in this documentation, but we've upped the frequency to better accommodate electrodes with small interfacial capacitance, like yours are likely to be). The divider's degree of attenuation is determined … text/html 2013-04-25T03:14:05+00:00 pkc http://www.mosaic-industries.com/embedded-systems/instrumentation/conductivity-meter/calibration-equations This page describes the computations performed by the Conductivity Sensing Wildcard's software-drivers. Those computations convert the voltage output of the Wildcard into an indication of the conductance/conductivity of the solution sampled by a conductivity probe/electrode. However, if you use the board as a stand-alone instrument, and read its output voltage with a precision voltmeter, you will need to do the computations yourself. To make that easier, we provide an Excel spreadsheet that allows you to enter calibration data and the measured voltage, and computes the conductivity for you. While you may use that spreadsheet without a detailed understanding of how the computations are done, it helps to have a basic understanding. If you want to measure the output of the Conductivity Sensing Wildcard with an A/D or other embedded computer, you'll need to implement these equations in code on another processor. text/html 2013-04-25T03:08:51+00:00 pkc http://www.mosaic-industries.com/embedded-systems/instrumentation/conductivity-meter/measurement-conductance-cell-constant Precisely measure the conductance of aqueous or non-aqueous solutions. The conductivity sensing Wildcard is a precision instrument for measuring the electrical conductivity of ionic solutions. It converts the solution conductivity to an analog voltage that is precisely measured using the Analog I/O Wildcard's 16-bit A/D. The board may also be used in stand-alone operation, in which the output is measured with a handheld digital voltmeter. [Conductivity-transmitter-connects-to-a-conductivity-probe-and-produces-an-analog-voltage] Conductivity transmitter specifications • 2 channels of conductance measurement • Outputs of 0-1 volt, proportioned to a 1.000 V reference, or 0-4.9 V full scale. • Directly connects to the 16-bit resolution inputs of the Analog I/O Wildcard • Provides its own reference voltage which may be used as the reference for the Analog I/O Wildcard text/html 2013-04-24T07:51:44+00:00 pkc http://www.mosaic-industries.com/embedded-systems/instrumentation/conductivity-meter/fluid-conductivity-calculation The Conductivity Sensing Wildcard software driver makes it easy to calibrate and use different fluid conductivity probes or conductivity cells. The driver routines perform zero and full scale calibration, measure the response of the Conductivity Sensing Wildcard when an attached probe is immersed in a solution, and calculates the conductivity of the solution. All nonlinearities are accounted for in calculations highly optimized for execution speed, with a single conductivity measurement taking 8.2 ms on the Mosaic PDQ Board and 24 ms on Mosaic's Q-line controllers. EEPROM space is automatically allocated for persistent storage of calibration data for up to four conductivity probes, and additional EEPROM space may be allocated manually for any number of additional probes. The software provides an easy to use interface for calibrating conductivity probes. The driver also provides a method to extract calibration data, making it easy to store factory calibration points or to transfer the conductivity probe to another instrument. conductivity-meter index text/html 2013-04-24T00:03:34+00:00 pkc http://www.mosaic-industries.com/embedded-systems/sbc-single-board-computers/hcs12-9s12-freescale-development-board/microcontroller [Low-cost-9S12-prototyping-and-developer-board Overview The PDQ Board Lite is a low cost single board computer (SBC) and development board that hosts the Freescale HCS12/9S12 MCU and an embedded RTOS. This GNU C programmable instrument controller is ideal for data acquisition and control, PWM drive, I2C sensor interfacing, laboratory automation, scientific instruments, SCADA, instrumentation and automation. The PDQ Board Lite is an even lower cost version of the PDQ Board with less memory and without some lesser used features (like RS485 and the battery backed calendar clock). It uses the same Freescale HCS12 processor and it is programmed in the same way, using the Mosaic IDE Plus. Its MC9S12A512 processor is operated in "single-chip mode", relying on only the processor's internal memory. The PDQ Board Lite provides all the I/O of the processor chip itself, including dual logic level and standard RS-232 serial ports, analog inputs, I2C, dual SPI links, PWM, and timer-controlled digital I/O. The dimensions are the same as those of the PDQ Board, with the same analog and digital I/O headers. It …