How to create a circuit drawing that allows easy mapping for setting up a breadboard I've read the post  and whilst it does contain a lot of useful information, it doesn't address my question about a drawing to be use for breadboards.  As I progress through learning EE (with help from the Arduino), I’m finding that creating circuit diagrams is becoming a little awkward, and I’m not sure what is the ‘right’ way of doing this to make it better/clearer.   I create circuit diagrams, then load up breadboards using the diagram as a guide, so a messy diagram is really unhelpful. (I am not planning on creating circuit boards at all at the moment. This is just a hobbyist/learning process, as I play with different circuits, components etc)  Basically, I’m coming up with instances where multiple ICs are creating a LOT of cross over wires making it incredibly difficult to trace things through or easily see what connects to what.   A simple example is trying to link up an 8x8 LED Array (1088BS) to a MAX7219 Led Driver chip. The Pin I/O of each device is not helpful, and just looks like spaghetti on my drawing when I connect everything together.  I’ve currently switched to drawing each IC multiple times, so I can see the I/O in the correct order from each side. In the following drawing, the top half and bottom half of the page each only detail 2 ICs each, although 6 are drawn. (this was drawn using Visio until I learnt the right way to do it in an EE design application)   If I drew this diagram, with the ICs side by side, and the pins in the correct place, as it would be on the breadboard, it would just be an unusable mess.  What is the ‘correct’ way of drawing this kind of design?  And would the ‘correct’ way be more beneficial to me as a guide to laying out breadboards? (and later on vero-boards)  The more I think of it, the more I'm thinking that it may not be possible to achieve, and I should change my approach to the problem rather than creating yet another drawing.
Rules and guidelines for drawing good schematics There are a lot of poorly drawn schematics here. A few times people have actually asked for critiques of their schematics. This question is intended as a single repository on schematic drawing rules and guidelines can point people to. The question is  What are the rules and guidelines for drawing good schematics?     Note: This is about schematics themselves, not about the circuits they represent.
Why aren't people voting for questions? While at least some answers from every question seem to have been up-voted as a "helpful" answer:   about 49% of questions have score of 0 or 1. another 21% of questions have a score of 2.   Most questions seem to have an answer or two with score +5. Is it that we have a lot of fluff questions and not useful ones? Or perhaps it just seems more natural to vote for answers than questions? If we want the most useful info on Stack Overflow to filter to the top, how can this disparity be fixed?  I think this may cause real problems for people getting the badges which require +25 or +100 votes on questions.    I like a lot of the feedback I'm seeing. Two problems are highlighted:   The work flow doesn't promote voting for questions the way it promotes voting for answers. One solution: when a user answers a question, the system should invite them to vote for the question.  If someone cares enough to answer a question, then they care enough to vote for it as well. Users with less than 15 reputation cannot vote for questions or answers. Is this warranted?  Maybe these users could provisionally vote for questions and answers and those ratings would only take effect when the user reaches 15 reputation?   All I ask is this. As you browse Stack Overflow, when you see a good question: vote for it.  If everyone does, then this problem will disappear. I am searching for [free] software that can produce nice looking graphical models, e.g.     Any suggestions would be appreciated. What do the plus and minus signs mean in Objective-C next to a method? How to read ext4 partitions in Windows? I have two questions on ext4:   Is there currently a way to mount an ext4 partition in Windows (XP/Vista/7) to get basic read support? If not, are there any plans to support this someday? Why does Linux require that a user be root/using sudo/specifically authorized per mount in order to mount something? It seems like the decision as to whether to allow a user to mount something should be based on their access rights to the source volume/network share and to the mount point. A couple of uses for non-root mounting are mounting file-system images to a user owned direction and mounting a network share to a user owned directory. It seems like if the user has control over both sides of the mount equation everything should be cool.  Clarification of access restriction:  I feel I should be able to mount anything that the user otherwise would have access to to a mount-point that the user is the owner of.  For instance, on my computer /dev/sda1 is owned by user root and group disk with permissions brw-rw----. Therefore non-root users can't mess with /dev/sda1 and clearly mount shouldn't allow them to mount it. However if the user owns /home/my_user/my_imagefile.img and mount point /home/my_user/my_image/ why shouldn't they be able to mount that image file on that mount point with:  mount /home/my_user/my_imagefile.img /home/my_user/my_image/ -o loop   As kormac pointed out there is a suid problem. So some restrictions would have to be added to prevent suid from being a problem as well as potentially some other issues. Perhaps one way to do this would be to make the OS treat all files as belonging to the user that did the mounting. However for simple read/write/execute, I don't see why this would be a problem.  Use case:  I have an account in a lab where my home space is restricted to 8GB. This is tiny and very very annoying. I would like to mount an nfs volume from my personal server to essentially increase the amount of room that I have. However, because Linux does not allow such things I'm stuck with scp'ing files back and forth to stay under the 8GB limit. Draw a bivariate normal distribution in TikZ For a small class I want to draw a bivariate normal distribution and show where the means from the two variables meet in the space. Has anyone done this in TikZ? What is the need for Autobiographer badge? What is the reason that Autobiographer badge is kept in Stack Exchange?  This does not show any participation and people can just fill garbage to achieve this badge.   Is there a reason behind it? I'm pretty sure the answer to this should be obvious - even to me ...  It's been a while I've been reading and attempting to construct simple electronic circuits. The supply almost always is either through a battery/cell, or AC duly rectified to DC.   I have the impression electronic circuits rarely ever work off an AC supply.    Is this impression correct? If yes, why is an electronic circuit rarely (if ever) powered/biased using straight AC? Why is it dangerous use a coiled extension cord For a given ellipse, find the locus of all points P for which the two tangents are perpendicular.   I have a trigonometric proof that the locus is a circle, but I'd like a pure (synthetic) geometry proof. Why did the writers select the date November 5, 1955 in Back to the Future? Is there any significance to the date November 5, 1955 that was chosen in Back to the Future? Is it one of the directors birthday or something like that or were there specific real life events that day in history?   I am not looking for in-universe answers. Consider a cement block of the same density as sea-water resting on the (perfectly polished) seafloor. I also assume the side-faces of the cement block are highly polished, so that no vertical hydrostatic forces can attack on them. A cable is attached to the top of the block.  My question ist: How much force must one apply to the cable before the cement block begins to lift off the seafloor?  The normal response would be to say that only a negligible force is needed - as the block is practically suspended in the water.  However, as the bottom surface of the cement block is not in contact with the water, it is NOT experiencing the hydrostatic pressure from below - only from above.  Before the crane starts lifting, the (zero-sum) forces on the cement block are:  $$F_{Seawater Pressure} +F_{Gravity on Cement Block} - F_{Seafloor Resistance} = 0$$  as the crane starts applying Force, the Seafloor will reduce its Resistance in the same measure, leaving the forces on the cement block zero:  $$F_{Seawater Pressure} +F_{Gravity on Cement Block} - (F_{Seafloor Resistance}+F_{Crane}) = 0$$  Just before the Cement block lifts, the Seafloor will stop applying Force and the Crane will be applying the only upward Force:  $$F_{Crane} = F_{Seawater Pressure} +F_{Gravity on Cement Block}$$  Once the Cement block lifts off the sea-floor, hydrostatic pressure kicks in on the lower cement surface, suspending the block, but before that - boy does it take a lot of force to lift it!  What is wrong with this reasoning? Does $k+\aleph_0=\mathfrak{c}$ imply $k=\mathfrak{c}$ without the Axiom of Choice? I'm currently reading a little deeper into the Axiom of Choice, and I'm pleasantly surprised to find it makes the arithmetic of infinite cardinals seem easy. With AC follows the Absorption Law of Cardinal Arithmetic, which states that for $\kappa$ and $\lambda$ cardinal numbers, the larger infinite and the smaller nonzero, then $\kappa+\lambda=\kappa\cdot\lambda=\max(\kappa,\lambda)$.  I was playing around with the equation $k+\aleph_0=\mathfrak{c}$ for some cardinal $k$. From the above, it follows that $\mathfrak{c}=k+\aleph_0=\max(k,\aleph_0)$, which implies $k=\mathfrak{c}$.  I'm curious, can we still show $k=\mathfrak{c}$ without the Axiom of Choice? Is it maybe possible to bound $\mathfrak{c}-\aleph_0$ above and below by $\mathfrak{c}$? But then I'm not quite sure such algebraic manipulations even mean anything, or work like that here. Certainly normal arithmetic does not! Thanks. Inverse of this $3\times 3$ matrix using the Cayley–Hamilton theorem Find the inverse of the matrix $$\begin{pmatrix} -1 &amp; 2&amp; 0 \\ 1&amp; 1 &amp;0 \\ 2 &amp; -1&amp; 2 \end{pmatrix}$$ using the Cayley–Hamilton theorem.  Thanks! Is there a free or open source library to read Excel files (.xls) directly from a C# program?   It does not need to be too fancy, just to select a worksheet and read the data as strings. So far, I've been using Export to Unicode text function of Excel, and parsing the resulting (tab-delimited) file, but I'd like to eliminate the manual step. Suppose we have a set $S$ of real numbers. Show that   $$\sum_{s\in S}|s-x| $$   is minimal if $x$ is equal to the median.    This is a sample exam question of one of the exams that I need to take and I don't know how to proceed. If $\alpha$ is a real root of the equation   $$x^5-x^3+x-2=0$$   find the value of $\lfloor {\alpha}^6 \rfloor$.      This one totally stumped me. We are asked to calculate $\lfloor {\alpha}^6 \rfloor$ without actually calculating the root or using wolfram alpha or any other calculator. I found that the above equation has only one real root by sketching its graph using calculus. I was also able to use the intermediate value theorem to conclude that $1&lt;\alpha&lt;2$ , but this is of little use while calculating $\lfloor {\alpha}^6 \rfloor$. Please help! What is so called meta-game in StarCraft 2?    What other games have this meta-game? Why is there no last activity message? Linux ACL behaviour: settings the mask changes 'ls' output, but not actual permissions It might be the time of night, but this is puzzling me. Picture the following.  [root@node1 acltest]# getfacl foo/ # file: foo # owner: root # group: testuser user::rwx group::r-x other::---  [root@node1 acltest]# ls -la . total 24 drwxr-xr-x  3 root root     4096 Feb  9 21:53 . drwxr-xr-x 25 root root     4096 Feb  9 21:54 .. drwxr-x---  2 root testuser 4096 Feb  9 21:53 foo [root@node1 acltest]# setfacl -m m::rwx foo [root@node1 acltest]# getfacl foo/ # file: foo # owner: root # group: testuser user::rwx group::r-x mask::rwx other::---  [root@node1 acltest]# ls -la . total 24 drwxr-xr-x   3 root root     4096 Feb  9 21:53 . drwxr-xr-x  25 root root     4096 Feb  9 21:54 .. drwxrwx---+  2 root testuser 4096 Feb  9 21:53 foo [root@node1 acltest]# su - testuser [testuser@node1 ~]$ cd /acltest/foo/ [testuser@node1 foo]$ ls -la . total 16 drwxrwx---+ 2 root testuser 4096 Feb  9 21:53 . drwxr-xr-x  3 root root     4096 Feb  9 21:53 .. [testuser@node1 foo]$ touch bar touch: cannot touch `bar': Permission denied   In words: I create a directory foo, with mode 0750, root as owner and testuser as the group. (testuser is the private group of testuser, but that doesn't matter.)  The getfacl command correctly shows no ACL's on this directory and there is not mask yet. The mask will be set accordingly to the group permissions if I would add a named group or user now.  If I explicitly set the mask to rwx now, the group permissions as shown by ls change too. I know it happens the other way around (the mask changes when the group permissions change), but this seems puzzling.  The more puzzling because the getfacl output does not show the group permissions as rwx but - as said - ls does.  Which one is right? Apparently, the output of getfacl is right, because testuser cannot write to foo. As expected, by the way, because I did not grant the testuser group any permissions to do so.  It goes on. I cannot allow the testuser group write permissions on foo by just using chmod. I have to explicitly set an ACL using setfacl -m g:testuser:rwx foo to allow testuser to finally touch foo/bar.   Can someone explain the rationale behind the difference in the outputs of getfacl and ls? I know it can be tricky to have normal permissions go together with ACL's, but this seems plain wrong. (Though I expect to be missing something glaringly obvious ;))  I have already seen