I'm designing a digital I/O module which isolated with optocouplers. I'm done with the outputs, but having a confusion about input side.     I will have some switches and sensors to read as inputs, but I don't know how to do the connections, can someone show me as a schematic?  Which pin should be GPIO pin for example?
I'm designing an I/O module by using optocouplers for the inputs and outputs which I want to control by a microcontroller.   Here are my questions:   In the datasheet of optocoupler's output current (per channel) is 50mA, and for the output port(figure 1) Relay nominal operating current is 16.7 mA. By knowing these can I calculate how much current will I need for the system. Which parameters do I know?   There are 12 relays, 20 optocouplers (5 module) in total. 3 Opto module for output, 2 for input ports     By directly connecting the GPIO pin and output of the optocoupler to the switches (as input), Can I control the inputs shown in the figures. For the input ports, I don't know how to make the connections. What should I connect to the collector pin?
Justifying $\,\Bbb{Z}[i]/\langle 2\rangle\cong \Bbb{Z}[X]/\langle X^2+1,2\rangle\cong \Bbb{F}_2[X]/\langle X^2+1\rangle$ I am asked to describe the quotient ring $\,\Bbb{Z}[X]/\langle X^2+1,2\rangle$ in two different ways. I would say that $\Bbb{Z}[X]/\langle X^2+1,2\rangle$ is isomorphic to $\Bbb{F}_2[X]/\langle X^2+1\rangle$ and $\Bbb{Z}[i]/\langle 2\rangle$ but I am not sure how can I justify that. Does we have $\langle X^2+1,2\rangle=\langle X^2+1\rangle\langle2\rangle$? I think the answer is no, because $\langle X^2+1,2\rangle=2P(X)+(X^2+1)Q(X)$. How can I justify the two isomorphism ? Einstein-Hilbert action as an effective field theory I have read the following statement:      "The Einstein-Hilbert action can be seen as an effective field theory: setting $g_{\mu\nu}= \eta_{\mu\nu}+h_{\mu\nu}$, one gets a free Lagrangian for the field $h_{\mu\nu}$ plus interactions."   Now, how is it possible to define all the interaction terms?  EDIT: I ask apologize if my statement was appeared unclear: I have created a  which is more precise; please don't continue to consider seriously this one. The use of "real" in the following cases Possible Duplicate:             If you listen real close...      Can you swing by real quick...   Sentences like the above two are what I often hear in daily life. If I didn't hear them in the real world, I would probably be more ready to say "If you listen really close..." and "Can you swing by really quick...".  Is real being used as an adjective in this scenario? If so, is the usage of adj.+ adj. a common practice in English language? A specific file on our production servers is being modified at apparently random times which do not appear to correlate with any log activity.  We can't figure out what program is doing it, and there are many suspects.  How can I find the culprit?  It is always the same file, at the same path, but on different servers and at different times.  The boxes are managed by , but the puppet logs show no activity at the time the file is modified.  What kernel hook, tool, or technique could help us find what process is modifying this file?    lsof is unsuitible for this, because the file is being opened, modified and closed very quickly.  Any solution that relies upon polling (such as running lsof often) is no good.      OS: Debian testing Kernels: Linux, 2.6.32 through 3.9, both 32 and 64-bit. Make all footnotes numbered subsequently, but one with a symbol Check if a user has a role How can I check if a user has a certain role?  I found  but it is for Drupal 6. Why is the gravitational force always attractive? Why is the gravitational force always attractive? Is there another way to explain this without the curvature of space time?   PS: If the simple answer to this question is that mass makes space-time curve in a concave fashion, I can rephrase the question as why does mass make space-time always curve concavely? Why are there both Static and Kinetic Friction? When dragging an object, there is a greater start-up force than the force it takes to keep it moving. Why is this? Why are there two different values for friction? How did Dumbledore gain the loyalty of Fawkes? How did Dumbledore find Fawkes. Did Dumbledore have Fawkes even when working as a Transfiguration teacher or acquired it after having Headmaster position. They both have a very strong bond between them. When did Dumbledore gain this. Update: Dumbledore says that Ollivander wrote to him when Harry's wand was purchased; if Dumbledore did not have Fawkes before 1938, he would not know about the two feathers being in the wands, so Fawkes and Dumbledore must have met and bonded before 1938  “My wand's feather came from Fawkes?” Harry said, amazed. &quot;Yes,” said Dumbledore. “Mr. Ollivander wrote to tell me you had bought the second wand, the moment you left his shop four years ago.” -Harry Potter and the Goblet Of Fire, Chapter 36-The Parting Of the Ways.  Update 2: JKR says that Dumbledore was the only owner of Fawkes. So it is to be believed that Fawkes was a wild Phoenix before its bonding with Dumbledore.  Peter Humphreys for BBC Newsround: Who did Fawkes previously belong to and will he play a vital role in the next book? JK Rowling: I am not going to answer about the role in the next books, which probably gives you a big clue, and he has never been owned by anyone but Dumbledore. You will notice that when Harry goes back in the Pensieve in this book, Fawkes is never there, and ­­ no, I am sorry, not in this book, I take that back. When Harry has previously seen the study with a different headmaster he saw it with Dippet and Fawkes was not there then. Fawkes is Dumbledore's possession, not a Hogwarts possession. Best way to draw matchstick pictures I want to draw various matchstick pictures like this:    or like this    or other figures from:   I want to use TikZ for this and have two questions about this:   How do I get the path decoration with the matchsticks? What's the (syntactically) easiest way to draw pictures like this or how would a TikZ expert do this (to be flexible enough to draw such kind of figures but to have an easy syntax)? Help needed with definite integral for $\lim_{n\rightarrow \infty}\sum_{k=1}^{n} \frac{1}{n+k}$ Suppose I have a question in my mind that I think is answerable but because I don't already know the answer, I'm not sure how to express in a way that makes it clear and definitively answerable. I suspect that someone more knowledgable than me would understand what I'm trying to get at though and could help me word the question properly.  Is there a good place to find this sort of help? Cooking steak in frying pan, problem with oil splatter I was using canola oil and put the stove top setting on "high - 9". I read plenty of guides suggesting there will infact be oil splatter, but it was pretty excessive and burning my arm with one drop getting near my eye before I stopped. I turned the heat setting down to "medium - 4", where the oil splatter seemed to drop substantially. Before I try to make steak again I'd like to get some clarification  So my questions are:   Which heat setting am I supposed to use? Is that type of oil splatter normal or should I try using a different oil, and if so, what oil? Should oiling the meat instead of the pan help the problem? To make it simple, I want to highlight a group of tikz nodes like in the following picture    It was borrowed from the . I would like to know which Tikz commands I can use to do the job in order to automatize this task for several trees I have to make. It is important to keep the blending effect of colors like in node g. Here is the MWE also borrowed from :  \documentclass{article}  \usepackage{tikz} \usetikzlibrary{arrows,backgrounds,calc,trees}  \begin{document} \thispagestyle{empty}  \begin{tikzpicture} \node (f) {f}     child { node (g) {g}       child { node (a) {a}     }       child { node (b) {b}     }   }     child { node (h) {h}       child { node (c) {c}     }   }; \end{tikzpicture}  \end{document} Why is $1$ not a prime number? Why is $1$ not considered a prime number?  Or, why is the definition of prime numbers given for integers greater than $1$? Are there any places to leave luggage in Brussels, for short and/or long periods of time? How can I respawn the Ender Dragon? I am a relatively recent graphic design graduate. I have been working at a small printing house for about two years, but will soon be interviewing for a different position in another city.  My question is about what to include in my design portfolio. When I was in school, my professors all insisted that work included in a portfolio should be 100% original: my original photography, my original logos, my original layout, my original written content etc. However, at my current office, we rely heavily on client-supplied logos, type content, and photography—and stock photography (shutterstock, etc).  What do other designers include in their portfolios? Has anyone else had this issue and can I reasonable include these more recent projects in my portfolio if I label them appropriately (something like "layout design")? Proving $f' = - \frac{\partial{F}/\partial{x}}{\partial{F}/\partial{y}}$ A few weeks back I was using std::ifstream to read in some files and it was failing immediately on open because the file was larger than 4GB. At the time I couldnt find a decent answer as to why it was limited to 32 bit files sizes, so I wrote my own using native OS API.  So, my question then: Is there a way to handle files greater than 4GB in size using std::ifstream/std::ostream (IE: standard c++)  EDIT: Using the STL implementation from the VC 9 compiler (Visual Studio 2008).  EDIT2: Surely there has to be standard way to support file sizes larger than 4GB.