Activity for Lundinâ€
| Type | On... | Excerpt | Status | Date |
|---|---|---|---|---|
| Comment | Post #276649 |
All that matters is that you prevent current rush in case of shorts or damaged electronics, anywhere on the PCB. For example in one EX project we used 1 ohm metal film resistors in series with each regulator since such resistors were apparently considered to break in a safe manner without sparks or h... (more) |
— | over 4 years ago |
| Comment | Post #276570 |
For EE a similar FAQ/listing/call it what you like, could perhaps be organized just like components at a silicon vendor site. "Amplifiers", "Passives", "Power management", "RF" and so on, with sub-categories. (more) |
— | over 4 years ago |
| Comment | Post #276570 |
@Olin "It will be a long time before we can determine which ones are asked frequently" But we do have quite some experience from EE at SE. "What are decoupling caps and what value should I use", "Please help me fix this LM317", "why doesn't this simple radio circuit work well" and so on. Sounds famil... (more) |
— | over 4 years ago |
| Comment | Post #276570 |
Ideally we'll have some on-site FAQ system eventually, but in the meantime we can use tag wikis or meta. Perhaps we should start there and write up a meta post with links to all the good stuff that's been posted in Q&A? Like "switch regulator" category, link 1 "how to design a flyback", link 2 "hummi... (more) |
— | over 4 years ago |
| Comment | Post #276570 |
I think we should probably rather be looking for a FAQ system where we can post a list of canonical posts, similar to the example I gave from SO's C FAQ: https://stackoverflow.com/tags/c/info. -> (more) |
— | over 4 years ago |
| Comment | Post #276570 |
"Are you saying we shouldn't try because it is doomed to fail, or that we should proceed but keep in mind the issues you raised?" I'm saying that this will need very stringent rules for everything, or otherwise it is probably doomed to fail. The "Documentation project" had lots of code/dev support, s... (more) |
— | over 4 years ago |
| Comment | Post #276602 |
Actually I addressed this issue back in December https://forum.codidact.org/t/allowing-specific-tag-topic-meta-discussions/432. Nothing came out from that discussion... except it does seem like we can use Q&A tags here on meta too, so it may be possible to set up a link collection that way too. (more) |
— | over 4 years ago |
| Comment | Post #276602 |
@manassehkatz Yeah so what we need is a working FAQ system, which was also the problem SO had since day 1. We could however use tag wiki for now, to maintain a list to high-quality canonical posts. Take for example the C programming FAQ I was pushing for over at SO: https://stackoverflow.com/tags/c/i... (more) |
— | over 4 years ago |
| Edit | Post #276602 | Initial revision | — | over 4 years ago |
| Answer | — |
A: Let's have a "Papers" category. My biggest concern is that it will get too random and low quality. The worst that can happen is something similar to SO's failed "Documentation project" a couple of years ago, where users were to write documentation and examples of misc programming-related topics. These ended up in a separate pla... (more) |
— | over 4 years ago |
| Comment | Post #276317 |
This is quite opinion-based. Basically, you may benefit from a RTOS if you have numerous different, complex processes that happen simultaneously. We are talking mid- to high end microcontrollers where you are well beyond 50kb program space and probably beyond 100k LoC. Or when you find yourself const... (more) |
— | over 4 years ago |
| Comment | Post #276294 |
@Olin Sure it can, the linkage & storage duration doesn't really matter. It's highly tool chain-specific what gets optimized away and what gets linked, it's nothing we can rely on cross-platform. Also note that it is very common for bare metal microcontroller programs to use a non-standard start-up, ... (more) |
— | over 4 years ago |
| Comment | Post #276378 |
You really should draw these from left to right. That is left=input voltage, right=output voltage. As done in every existing datasheet for switch regulators out there. (more) |
— | over 4 years ago |
| Comment | Post #276294 |
@Olin Then you would still have the possibility that the compiler may assume "Oh, that `UARTBR=0x42;` line is there, but the variable isn't used anywhere. Lets optimize away that line." I wouldn't gamble but keep volatile consistent across all registers. (more) |
— | over 4 years ago |
| Comment | Post #276154 |
Yet another trick: poke the manufacturer's tech support early on, to see if they are useful or if they hate to have customers. Similarly, can you get samples for the part or is that mission impossible unless you buy MOQ 10k? (more) |
— | over 4 years ago |
| Comment | Post #276154 |
Another important thing to consider: part status. Does the manufacturer list this as highly recommended or active? If not, stay clear of it. If you are considered an important-enough customer, you can also poke a large distributor (Arrow, Avnet etc) and ask them if this part is a "high runner" or if ... (more) |
— | over 4 years ago |
| Edit | Post #276290 |
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— | over 4 years ago |
| Edit | Post #276290 |
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— | over 4 years ago |
| Edit | Post #276294 | Initial revision | — | over 4 years ago |
| Answer | — |
A: How to access a hardware register from firmware? Using pointer types In C, an object pointer such as `uint8t ptr` is the equivalent concept to use for hardware addresses. A compiler makes this pointer type large enough to contain all addresses in the microcontroller's default address space. It is valid to convert from an integer to a pointer... (more) |
— | over 4 years ago |
| Edit | Post #276290 | Initial revision | — | over 4 years ago |
| Question | — |
How to access a hardware register from firmware? 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 and portably in standard C without using the pre-made register map delivered together with the compiler... (more) |
— | over 4 years ago |
| Suggested Edit | Post #276256 |
Suggested edit: (more) |
helpful | over 4 years ago |
| Comment | Post #276253 |
There's also an option 3), which is to hack together your own bootloader over SPI, UART, CAN etc. Many modern MCUs come with some manner of hardware support for writing bootloaders, meaning that you can do it even if the chip wasn't previously flashed. Though these are only for specialized needs, usu... (more) |
— | over 4 years ago |
| Comment | Post #276249 |
Regarding programming interfaces, each MCU family tends to have their own standard for connectors and signals. The most common ones nowadays for ARM, PowerPC and similar mainstream 32 bitters is JTAG and the spin-off called SWD. JTAG typically uses a plain 2,54mm/0.1in header, 2x10 or 2x7. SWD typica... (more) |
— | over 4 years ago |
| Edit | Post #276252 |
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— | over 4 years ago |
| Edit | Post #276252 |
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— | over 4 years ago |
| Edit | Post #276252 |
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— | over 4 years ago |
| Edit | Post #276252 | Initial revision | — | over 4 years ago |
| Answer | — |
A: What are the most common causes of CAN bus communication errors? 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 live bus, but other than that you shouldn't be seeing them or there are fundamental hardware or softwar... (more) |
— | over 4 years ago |
| Edit | Post #276251 | Initial revision | — | over 4 years ago |
| Question | — |
What are the most common causes of CAN bus communication errors? 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 selected bitrate, either high or low. Alternatively there is a "bus off" error and nothing works at ... (more) |
— | over 4 years ago |
| Comment | Post #276235 |
What about electric-power-infrastructure? Bit long but unambiguous. Alternatively something along the lines of power-grid? Input from someone working in that field would be interesting. (more) |
— | over 4 years ago |
| Comment | Post #276138 |
Almost all LEDs are specified @ 20mA nominal and you shouldn't give them more than that unless the datasheet says otherwise. As for forward voltage, it depends on if the white LED is a "blue LED in disguise" or a "yellow LED in disguise" - that is, based on different chemistries. "Blue:ish" white LED... (more) |
— | over 4 years ago |
| Comment | Post #276142 |
"Maybe there was a reason to make sure Q1 was really off and not picking up stray signals when the micro is powering up and the I/O pin is still in high impedance before the firmware sets it up." Indeed. Many MCUs set all their GPIO as inputs out of reset, to save power. From the time where the MCU g... (more) |
— | over 4 years ago |
| Comment | Post #276146 |
Things like component identification or repair questions are probably not suitable categories, we should rather just make rules for how they should be asked, as I've now noticed was already done here: https://electrical.codidact.com/help/compid. (more) |
— | over 4 years ago |
| Comment | Post #276155 |
Java isn't JavaScript :) (more) |
— | over 4 years ago |
| Edit | Post #276146 | Initial revision | — | over 4 years ago |
| Answer | — |
A: Are we there yet? Hi there! The on-topic page https://electrical.codidact.com/help/topics might need a bit of tweaking and discussion. I think it is important that such a page attempts to be as specific as possible early on, so I quite like it and agree with most stuff there. But a few other things might need t... (more) |
— | over 4 years ago |