I'm a bit confused by the datasheet of a LCD (MIKROE-55). It says supply voltage is 3.5V (TYP), which results in as Supply current of 16mA.  At first I understood this as: "connect K to GND and A to 3.5V and I'm done :)"  But below that table is a graphic showing 2 Resistors (1 on seems to be on boards, 1 external).  So my question: How to connect that backlight? If a Resistor is required, how to calculate its Value.  Full Datasheet can be found here:
I have a simple circuit:    The max rating (current) of the LED is 30mA.  How can I work out what the resistance of the resistor needs to be? By using ohm's law I found it to be \$3V/0.03A = 100 \Omega\$. However using software called , and trial and error I got the minimum possible resistance to be 36&Omega;. However, if I use a 35&Omega; resistor, then the LED breaks. Is the software wrong, or (more likely) am I doing something wrong?
In my past experiences, I have almost never typeset my manuscripts according to the formats required by the journals to which I would like to submit. I leave my manuscripts as produced by the LaTeX article documentclass.  Recently I am wondering: Would such a behavior generally give handling editors a negative first impression? What to do when I get an "attempt to read or write outside of disk 'hd0'" error and Boot Repair does not solve the problem? Would the One Ring have stayed hidden if Bilbo hadn't turned up? Medium with refractive index less than unity? E2099 Overflow in conversion or arithmetic operation Is it possible to use more than 20 layers? Is it possible to use more than 20 Scene layers or Render layers in Blender? Stack Overflow interesting questions implementation According to the tooltip of the 'interesting' tab, interesting questions are     "questions that may be of interest to you based on your history and tag preferences"   Does Stack Overflow use a recommendation engine or just some sql sort/filter? Should we @Override an interface's method implementation? What is the cause of this sudden drop in CV queue size? On the nature of the collapse of the wave function The collapse of the wave function by measurements is one of the most mysterious properties of quantum mechanics.    At what scale does the wave function collapse? What are the conditions for a collapse?  Can it be made precise?  Does the collapse happen instantaneously, or is it spread out in time?  What is the precise equation for the collapse?  Why is the collapse time-asymmetric, and can this explain the arrow of time? I have text file. Task - get first and last line from file after   $ cat file | grep -E "1|2|3|4" | commandtoprint  $ cat file 1 2 3 4 5   Need this without cat output (only 1 and 5).  ~$ cat file | tee &gt;(head -n 1) &gt;(wc -l) 1 2 3 4 5 5 1   Maybe awk and more shorter solution exist... Is it true that every pair of twin primes >3 is of the form 6n plus or minus 1? Is it possible to have twin primes whose center is not divisible by 6? I am looking for a way to get the 15 character entity ID for a custom field on my Lead object in an Apex controller. I have tried this:  private String getEntityIdFor(String fieldName) {         Map&lt;String, Schema.SObjectField&gt; fieldMap = Schema.SObjectType.Lead.fields.getMap();         return fieldMap.get(fieldName).getDescribe().getId();     }    Of course, there is no getId() method, but this is the closest I got.   Thanks for any help. What is a good method for short text clustering? I am working on a text clustering problem. The data contains several sentences. Is there a good algorithm which reaches high accuracy on short text?  Can you provide good references?   Algorithms such as KMeans, spectral clustering does not work well for this problem. Minor "you have already raised this type of flag" bug? I flagged something as spam, then was only 90% sure I'd done so, so I clicked the flag link again to check. It showed me this:    I had, of course, only raised the spam flag, not the offensive/abusive/hate flag, so the latter probably shouldn't be saying I did.    Ah, this may be a duplicate, I didn't search enough:        And if so, it's been around a while. Testing pointers for validity (C/C++) Is there any way to determine (programatically, of course) if a given pointer is "valid"? Checking for NULL is easy, but what about things like 0x00001234? When trying to dereference this kind of pointer an exception/crash occurs.  A cross-platform method is preferred, but platform-specific (for Windows and Linux) is also ok.  Update for clarification: The problem is not with stale/freed/uninitialized pointers; instead, I'm implementing an API that takes pointers from the caller (like a pointer to a string, a file handle, etc.). The caller can send (in purpose or by mistake) an invalid value as the pointer. How do I prevent a crash? From an array of objects, extract value of a property as array Well, just another idea came up into my mind and i have no idea how to solve it :D Is there infinitely many prime numbers, which are not repunits and their inverse is also prime? (For example, inverse of 31 is 13 which is also prime. i didn't have any other name to describe the function!) P.S:I now know they are called s. Keyboard macro to change default audio device Windows 7, Logitech G110 keyboard  2 audio devices (headphones and speakers)  I am hoping to find a quick way to macro a key to switch to headphones, and a key to switch to speakers.  Anyone have a good program or anything of that nature?  EDIT:  Using AHK to try and get this task working as hoped is sadly not doing the trick.  I have included a screenshot of my audio set, as well as a screenshot of my script as it sits now.    I have also tried to uncheck "show disabled devices" and modified the script to be Down 1, and Up 1 respectively.  It will work for one device, but it refuses to switch to the secondary. How to monitor USB power consumption? I'm looking for a way to monitor the power being drawn from the USB ports on my Mac.  System Profiler doesn't appear to display this and I haven't been able to find any applications or tools to do the job either.  Can anyone suggest anything (preferably software based)?