Activity for Lundinâ€
| Type | On... | Excerpt | Status | Date |
|---|---|---|---|---|
| Edit | Post #277912 | Initial revision | — | over 3 years ago |
| Question | — |
Getting rid of "company tags" early on I just made a post about using "company tags" over at Software Development: > We know from SO that company name tags were always problematic since: >- Questions are about products, not companies. >- Given that the product tag is present, the company tag doesn't add any relevant information to ... (more) |
— | over 3 years ago |
| Edit | Post #276256 | Post edited | — | over 3 years ago |
| Comment | Post #277845 |
So the only thing you changed was cap chemistry, not the capacitance? What does the layout look like? THR or SMD? X5R, NP0? (more) |
— | over 3 years ago |
| Edit | Post #277543 |
Post edited: |
— | over 3 years ago |
| Edit | Post #277543 | Initial revision | — | over 3 years ago |
| Answer | — |
A: How come the registers in a micro are application specific? They aren't specific to the project, but to the MCU. As long as you use the same MCU for multiple projects, they will be code compatible. Some hardware peripherals are even code compatible between different MCU families by the same manufacturer. Generally, registers are different in each and every... (more) |
— | over 3 years ago |
| Comment | Post #277541 |
Typically there is an actual register hidden beneath the addressable RAM location though, and hardware handles transitions between them. Like for example SPI will have an actual hardware shift register underneath the memory location called SPIDR. (more) |
— | over 3 years ago |
| Comment | Post #277467 |
@aditya98 433MHz can be used license free in most of Europe, Middle-East, South America, Australia and Africa. It has lots of restrictions in North America and South-East Asia, where it is typically either used for ISM or for RFID container systems. Frequency allocation world-wide is a complete mess ... (more) |
— | over 3 years ago |
| Edit | Post #277466 | Initial revision | — | over 3 years ago |
| Answer | — |
A: Why RC toys still operate in 27Mhz band? I can think of a couple of reasons: - Lower frequencies mean superior range at the same output power. Whereas for example 2.4 GHz technologies tend to behave much more "directional" on short ranges, they are basically line of sight and don't handle obstructing objects/terrain between sender and re... (more) |
— | over 3 years ago |
| Comment | Post #276662 |
Also from what I recall, you are supposed to increase the number of parallel zener diodes depending on safety class. From what I remember, EX class 0 with intrinsically safe system requires 3 zeners. Supposedly to even out the heat between them. (more) |
— | almost 4 years ago |
| Comment | Post #276669 |
@Hawk2020 You almost certainly need a consultant - contact some test house with a good reputation for EX/ATEX. You can usually hire them for a few days to do a design review of your system and point out problematic parts. It's not just the electronics, but all mechanics, plastics etc. These kind of p... (more) |
— | almost 4 years ago |
| Comment | Post #276649 |
Why Li-Ion btw? These are very nasty from an EX perspective. NiMH or NiCd etc are much safer, although they are of course bigger and heavier. (more) |
— | almost 4 years ago |
| Comment | Post #276649 |
I don't remember, but the idea was to block current rush in case each regulator fails and de-centralize current rush protection across the board, instead of relying on one single fuse. Thermal shut-down because of overcurrent is for example not feasible. But this was also a whole lot more complex ele... (more) |
— | almost 4 years ago |
| 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) |
— | almost 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) |
— | almost 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) |
— | almost 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) |
— | almost 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) |
— | almost 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) |
— | almost 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) |
— | almost 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) |
— | almost 4 years ago |
| Edit | Post #276602 | Initial revision | — | almost 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) |
— | almost 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) |
— | almost 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) |
— | almost 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) |
— | almost 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) |
— | almost 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) |
— | almost 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) |
— | almost 4 years ago |
| Edit | Post #276290 |
Post edited: |
— | almost 4 years ago |
| Edit | Post #276290 |
Post edited: |
— | almost 4 years ago |
| Edit | Post #276294 | Initial revision | — | almost 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) |
— | almost 4 years ago |
| Edit | Post #276290 | Initial revision | — | almost 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) |
— | almost 4 years ago |
| Suggested Edit | Post #276256 |
Suggested edit: (more) |
helpful | almost 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) |
— | almost 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) |
— | almost 4 years ago |
| Edit | Post #276252 |
Post edited: |
— | almost 4 years ago |
| Edit | Post #276252 |
Post edited: |
— | almost 4 years ago |
| Edit | Post #276252 |
Post edited: |
— | almost 4 years ago |
| Edit | Post #276252 | Initial revision | — | almost 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) |
— | almost 4 years ago |
| Edit | Post #276251 | Initial revision | — | almost 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) |
— | almost 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) |
— | almost 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) |
— | almost 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) |
— | almost 4 years ago |