Posts by Lundin
I keep hearing that dynamic memory allocation on the so-called "heap" segment should not be used in microcontroller-based embedded systems. Pretty much every safety standard like for example MISRA ...
Using pointer types In C, an object pointer such as uint8_t* ptr is the equivalent concept to use for hardware addresses. A compiler makes this pointer type large enough to contain all addresses i...
This question here about the OSI model was closed as off-topic. How should we treat questions about data communication? What is definitely on-topic here: Embedded systems programming, including...
When writing firmware in C for a microcontroller, how can I directly access a memory location such as a hardware peripheral register, given its absolute address? Is there a way to do this safely an...
One rule of thumb is that a CAN network should never have any error frames when it is up and running. It is expected to have some when all nodes are "waking up", or if you hot plug something to the...
Based on this nerdy but seemingly trustworthy site: https://www.prc68.com/I/TelephonePoles.shtml Then I would guess these are cable TV repeaters/signal amplifiers. Classic cable TV uses copper co...
As we know there exists numerous different kinds of PCB CAD software. The big ones seem to be Eagle, KiCAD, Altium, OrCAD, Solidworks, DesignSpark and probably a few more. When it comes to mechani...
RF novice here. If using a superheterodyne receiver for the purpose of FM/FSK modulated signals, I'm wondering if the location of an optional automatic gain control (AGC) circuit is always placed o...
I can't get my CAN bus application (ISO 11898-2, classic "high speed CAN") working and I'm receiving various CAN error frames. These error frames manifest themselves as sequences of 6 bits with my ...
When working with microcontrollers, one will sooner or later face the situation where the MCU is not responding. Either it's a new PCBA you are trying to get up and running, or something that prev...
Problem description & speculation about causes I've having a problem with MAX485 transceivers breaking intermittently, passing our production tests but later failing. The error phenomenon is w...
Coming from a background of safety-related applications and industrial control systems, with some maritime applications experience, I could offer a few insights. These kind of game controls are li...
Things happening/things we want to happen before main() is called: The code executed before main() is often referred to as "the C runtime (CRT)" or just "start-up code". This code is typically pro...
Whenever declaring a variable in C outside a function at file scope or when specifying it as static, it gets assigned a life time known as static storage duration. Meaning it will be accessible thr...
My scenario is this: radio equipment controlling an overhead crane inside a steel mill. Specifically it is used for transporting melting pots. With the current, unfortunate installation, the antenn...
After reading various low quality questions Someplace Else today, it (once again) occurred to me that a whole lot of people, mostly hobbyists and engineering students, have no clue how to do the mo...
Disclaimer: I'm not an expert of EX classification myself, but I once was project/product manager for such a project (a zone 0/20 intrinsic control system product). While I can't answer the questio...
Quite often, I find myself knowing the technical term of an electronic component in my native language, but not the proper English term. For example when translating a manual or other technical doc...
Assume I'm a complete beginner at RF. Is there a way to measure return loss of an antenna, in such a manner that I can reliably reproduce the measurement later on? What I'm talking about is produ...
Regarding scope of embedded systems/firmware When we released Software Development, I made a push to make all forms of embedded systems programming off-topic and re-direct such to this site. The ...
Which are the parameters I should looking for when picking a flyback diode to be placed across a generic coil, such as a relay? That is: a coil with plain on/off functionality, for example a 24VDC ...
Olin has posted a good answer regarding the pros and cons. To add to that, look at where your C code is going: if(strcmp...) else if (strcmp...) and so on. This is a common mistake in embedded C wh...
Searching for a tag name using a string that doesn't exist in any tag causes internal server error 500. Reproduce this way: Click Tags in the menu In the search box, type something that doesn'...
The black one is a tantalum capacitor. There are various weird ways to mark these (because typing out 100u instead of 100- would be too easy...). If I'm correct in this case, I believe: 100 stan...
I'm working on another project with extreme EMC requirements as per various notorious military EMC standards. Civilian product but for military use, and as such subject to the toughest levels of co...
