Given specific requirements one usually has a very wide choice of matching microcontrollers. Other than avoiding tags like "not for new designs" and such, is there anything one can do to ensure that the product one chooses is still available several years from now? Are there some manufacturers that are known to have longer lifecycles than others, or is that completely unpredictable in advance? Or is it just that I would have to order huge amounts of the part I plan to use for a long time?
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I need to use a microcontroller on a system that must stay working without major changes for a long time (decades). To ensure that there always will be replacement parts, I need a microcontroller that will be long run produced or produced by some manufactures in a firmware binary and encapsulation pin compatible way. What can I do to ensure that the microcontroller I choose meets these criteria?  The application doesn't need much computing power. Its aim is to control motors and other industrial systems. A microcontroller of 8 bits capable of changing the state of about 8-16 IO pins at a frequency of 0.5-1 MHz is OK. An ADC may be valuable, but can be replaced by a simple external comparator.
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I'm looking at rather short QVL lists from manufacturers, and I'm wondering what is the underlying cause of RAM incompatibility aside from the obvious: Obvious Reasons for Incompatibility  RAM Generation (DDR, DDR2, DDR3, DDR4) Form Factor / pin count RAM Type (ECC vs Non-ECC, Registered vs not, Buffered vs not) Minimum speeds on a board that cannot adjust the memory frequency Non-standard voltage range on a board that cannot adjust the memory voltage Channel count (single vs dual vs quad) Bad or inoperable module Mismatched set  Not Obvious Reasons  Brand SKU Max Capacity Speed too high  As in, why can't motherboard manufacturers just list the specifications of the RAM they will accommodate, and support every memory chip of that category instead of listing specific SKUs from specific brands? What happens electrically/physically that causes boards to fail to POST / operate with RAM that is otherwise 'compatible' with all of the specifications of RAM that is on the QVL?
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I have just bought some 555 timers and they are timers for microelectronic circuits...could anyone tell me what I need to search for in order to get larger ones which will fit a breadboard? Thanks
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How do I share a single crystal (not a complete oscillator module) between two micros? Is it OK to just connect everything as normal for the first micro and also directly connect its XO to the XI of the second microcontroller? I expect to place the micros very close together on the board.
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I'm trying to repair the logic board of an LCD monitor that died while giving off a burned smell.  It seems that an LCD driver chip and a MOSFET (I think) burned out. The chip was easy to identify () and order, but I can't unambiguously identify and find a replacement for the other part.  It is labeled "540N 88KFG" and I think its form factor is TO-252 / DPAK. Below is a photo, there are three of them in the middle of the picture.  A related question is what characteristics I have to make sure to match if I can't buy an exact replacement. Searching around for "540N" MOSFET, I found some in other packages whose main data points were   100V source-drain voltage 33A current rating.   If those do indeed apply to this component as well, what else needs to match in a replacement?  Update: After looking around a bit longer it appears that  might be a reasonable replacement.
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I would like to use an ATtiny2313 to emulate a Super Nintendo controller because I have an ATtiny2313 but I do not have an input shift register and I don't feel like soldering wires onto an existing SNES controller board.  This application requires 12 inputs (bits 13-16 are always 1) and a latch, clock, and data out pin.  Do you have this code lying around? It can't be more than 20 instructions.
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I have not seen a single reference where a whole computer is built inside a chip itself instead of modularizing and spreading it on a board. I acknowledge that having modular parts enable versatility, but can big silicon companies such as Intel, AMD produce a whole computer with cpu, chipset, RAM, memory controllers, all in a microchip? I am familiar the concept of SoC but havent seen ALL the components inside single chip.
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I haven't been able to come across definitive information regarding the procedure to find out whether an electronics product (PCB) requires CE marking or not.  Since it is difficult to ask hypothetical questions, let me ask by using specific examples. Let's take  as a first example. Would this product require CE marking to be sold in Europe? (Maybe a similar question: would this product require any FCC approval/marking to be sold in the USA?)  Let's look at a . This is an A/D board. Would this product require any regulatory approvals/markings?  It would be a great help if someone with CE/FCC experience could give answers, explaining the reasoning behind those answers.
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I guess it's a silly question but i don't get it xD.  I've read it's about controllers, but they can be downloaded from manufacturers, right?
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I am doing one hobby project, using STM32F103R8T6 Micro controller for my project, I would like to use USB transceiver for this micro controller,  does this helps me to update my firmware program through USB interface or do I need to have separate programmer for uploading firmware to microcontroller.
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Before starting: lets forget about the EULA and any other legal regulation. I'm not interested in those. Also, since this is a grey line about what I'm going to ask, Ask Different may not be the place to ask:     Installing or using Apple operating systems on non-Apple hardware (and most other explicitly unlicensed use of product)   Continue reading.    Everyone knows that until some years prior OSX (or Mac OS) only could be run in PowerPC CPU's, but that changed when Apple adopted Intel CPU's opening the possibilities of installing OSX in PC's (again lets forget about legalese I'm going for factual and technical references) that users started experimenting until it's is possible. So, anyone knows why is the reason that OSX wouldn't work in normal folks PC? Some piece of hardware that is made custom tailored for OSX that only Mac's has? Or is just Apple folks making users life difficult at technical level?  The question is a mere curiosity of mine, inspired in an very debated answer of mine about installing Mac OS X in a Dell PC.  TL;DR: How they make it so difficult?  References (can be used in answers ;) ):
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I need to encode information about either version or configuration on the board/electrically, so the firmware can detect which board layout is used.  What options are possible and what are their pro/cons?
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I have a bluetooth remote control device that uses 2 AA batteries. Due to positive feedback and responses, I'm thinking to sell it to mass market. Thus I need FCC certification.  After reading many articles including all the FCC related questions in this site, I'm still confused.   There are many of wireless products in US market that don't have FCC / CE certification. Many of imported products sold in Amazon don't have the certification.  With such a high cost ($10,000-$20,000), I don't think many small company can afford to get this certification.  What is consequences if you sell the product without FCC certification? Before I apply for FCC, what are the things that I need to watch out, especially my PCB. Do I have to care about the box(enclosure)?  I mean, my product uses 2 batteries, I don't think it will cause a fire hazard or short circuit. Or if I have to watch out for fire hazard, what component should I add? The bluetooth module is already certified by FCC and CE. So I will be exempted for the Bluetooth test. But I guess they still need test the product as a whole. What if you failed for the first test, do you have to redo all over again and pay another $10,000?   Thank you.  Dan  Additional info: Q:  I’m a retailer, why should I care about FCC regulations? A:  It is illegal to import, sell, or operate covered equipment that has not undergone the required equipment authorization procedure. Illegal merchandise can be subject to forfeiture, and you may be subject to fine. Imported merchandise that does not have FCC may be held at customs. Also lack of FCC compliance means the merchandise has never been evaluated for electronic compatibility. This is a sign of bad quality. What other safety or chemical regulatory requirements might not have been evaluated?  FCC enforcement action is often levied against retailers and end users, especially where the manufacturer is located outside US jurisdiction.
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I'm making my second USB design, but the D+/D- pins on the MCU (atemga16u2) aren't in the right order for the micro B connector. What's the best practice for routing these to go the right way? My current idea is to rotate the atmega 180 degrees and route them under, but it feels like the traces are fairly long. I could also drop one of the lines under the other, but I'm sure that would mess with the lengths for the differential pair. This device won't go over Full Speed, so I can get away with less than perfect routing.
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A quick google around and all I seem to be able to find are people talking about the physics &amp; the chemistry of the capacitors but not how this affects choosing which to use.  Avoiding talking about the difference in their make-up, and the larger capacities found in electrolytic caps, what are the main thoughts that drive which type of capacitor to use for an application?  For example, why do I see it suggested to use ceramic caps for power decoupling per microprocessor &amp; a larger electrolytic capacitor per board? why not use electrolytic all around?
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I am buying a new desktop PC in early 2013, anyway this question should apply to someone intending to buy a new laptop/ultrabook as well.  This machine is not meant for gaming, and if I ocasionally do it, I can survive with minimum graphics. However I may need some heavy multimedia edition or multitasking at times, so basically  my greatest priority is a good processor, after that perhaps average graphic card (if onboards are not enough, I am still not informed enough about that), at least 4GB of RAM with possibility of expansion.  I know there are some PC models specially designed to ship with Ubuntu, which is the OS I use the most these days. However, most people around me use Windows and some software with unsupported versions for Linux and not having a Windows license becomes a bit problematic.  Given that, I would like to find information about which PC models or even manufacters currently on the market have the best compatibility with Ubuntu, I am still undecided between building my own desktop or buying a pre-made model, so I would like to find information both for certified models and certified hardware or even Ubuntu partners that may work closely with Canonical.  Where to find this information in order to make sure that I will have a good experience with Ubuntu on my new PC in the years to come?
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Why does everyone use PLCs in industrial environments, instead of a microcontroller based solution?  For a longer task, the PLC program is as complicated as a microcontroller program.   A microcontroller based solution may be more customisable, and of lower price.