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Thank you very much to make me understand this...

Renewable Energy / Re: When Will Electric Cars Become Mainstream?
« Last post by james_s on Today at 03:44:16 am »
I haven't really found laptops to be all that fragile. I've never actually had one break, I've only replaced them because of technological obsolescence. My partner is still using the Lenovo I bought in 2011.

I have an old iPad somebody gave me and the only thing I've ever really found it useful for is viewing PDF manuals. Typing on a touchscreen is hopeless.
Try an inter-library loan with your local uni library. See how far you can push the system...
Good idea and working on it but I doubt if it would work. The best way is that a good friend overhere help me.

The bad point is that this manual is out of stock everywhere and the author is passed away and there is no one in the D C W Industries publisher to answer me. Too much complicated situation!
General Chat / Re: Soldering standards on YouTube
« Last post by james_s on Today at 03:40:32 am »
We have an inspection here when licensing a new trailer but you don't have to keep getting it inspected. We have emissions testing for cars more than 3 and less than 25 years old, thankfully mine are old enough to be exempt. I remember going through the tests years ago and wondering if the pollution of all those cars idling in line and driving on the dyno all day long was offset by fixing the few cars that failed the test. The worst failures often got away anyway because after spending a certain amount having the car repaired you could get an exemption if it still failed. I think the emissions testing made a lot more sense back when cars were a lot dirtier and required regular tuneups. Modern cars don't have to be adjusted and will warn you if there's a fault that affects emissions.
Beginners / Choosing a display for device
« Last post by mmrvelj on Today at 03:40:07 am »
Hi all

We have subcontractors that design a device for us. Device is like appliance (1RU) that will be installed in 19" rack in server room.

We are asked to define the display that will be put on front panel of the unit.

The purpose of display will be to provide elementary status information, help with initial configuration, and in some case display some simplified graphical information (that might need updates up to 2 times per second).

Some of the parameters:
  • reliable operation 24/7 for 5 years
  • able to display simple graphics
  • does not emit too much light (avoid distraction) - option where backlit (if there is one) can be turned on/off is acceptable
  • height not more then 38 mm
  • can be easily procured
  • number of devices to be produced in one production batch: 10-20
  • cost  < ~50 $ per display (current idea might be increased if there is a good reason)

I could really use a good advice/pointers on the type of display (technology, model) to choose. What should be taken into consideration when selecting the display?

Microcontrollers & FPGAs / Re: STM32 without STM Libraries
« Last post by mark03 on Today at 03:37:08 am »
If you use that there will be no actual library available and everything must be done by direct access to registers using your own code and through readings of the manual. This can be the most laborious route for your purpose, but it will result in the smallest code size.

This is how I do most of my work, and it's a lot less work than people seem to think.  The best part is I only need ONE document open (the reference manual), and I can code straight from that, because the register and bit field names in the CMSIS headers follow the reference manual exactly, with very few exceptions.  When I am forced to use a library I am constantly hunting around for the right constants and function names; this wastes a lot of time and is no fun at all.  Obviously, writing your own drivers is more work in some sense, but if you stick with a family like STM32 you very quickly get to the point where you are just copy/pasting from previous projects with small modifications.
Test Equipment / Re: New Keithley DMM6500 and now DAQ6510
« Last post by MrFox on Today at 03:35:50 am »
Ah ok, Brad already explained it in a previous post...
The fastest is actually to use a trigger model, because there's a separate processor for it. I am curious why the default CONT mode isn't just that trigger model.

Probably you set the digitize Count to 1 and went into continuous trigger mode?  When you do that, triggering is handled by the display processor, so when that processor gets busy it will stop triggering and catch up with whatever else it's being told to do (like update the graph image).  That's where those gaps in data are coming from.  A couple ways around this come to mind:
  • Set a higher count to capture all the data you need.  Triggering within a Count set is handled by a separate processor that won't get caught up in display stuff, you also won't see the lines connecting separate groups of data that may be a little confusing.  The graph's smart scaling in x will by default show you the latest group of readings.
  • Use a trigger model.  Triggering from a trigger model is also handled by a separate processor and a very simple model can allow continuous data capture.  I'm attaching a script (change the .txt to .tsp to use it) where the last lines set up a trigger model that starts a digitize voltage measurement (that continues infinitely) and then stops the measurement when the TRIGGER key is pressed.  The display might lag behind slightly depending on your other settings, but there won't be any gaps in the data.  If you digitize at a really high rate then you may see a pop-up like "Processing reading backlog...".  That message means the display processor needs to catch up with the data buffer and it will stop other activities until it catches up, usually no more than a second or two.
General Chat / Re: looking for specific bjt
« Last post by Benta on Today at 03:34:11 am »
what bjts come in to220 with very low thermal resistance between junction and case? Im looking for sub 1 C/W parts.

Extremely few, I know of none. Does it have to be TO-220? TO-3P or TO-247 would be a better choice if you have space.
Example, just a starting point:

AMD Ryzen TR 2950X vs Intel Core i9-9900K
Userbenchmark Effective CPU Speed: 117% vs 121% 
AMD Ryzen TR 2950X  - 8th / 1143 
Intel Core i9-9900K  - 3rd / 1143

A lot of Software (Altium, Solidworks, Adobe, you name it) can not use all the AMD 2950x "horses", really? So the I9 9900K still wins in real life because it has less horses but "faster"?

I am planing to build a new PC soon and the more I read and research the more I am shocked how apparently it's difficoult to write software code which runs on multi-core  at the same time.

Do you expect a change in the software industry soon? If yes I maybe bank out a 2950x.

Hope you guys can teach me something because I am kind of confused about the situation right now...
HARDWARE INDUSTRY: More core as possible.
SOFTWARE INDUSTRY: Let's continue to use just 4 of them, we don't want to rewrite the multi-core code from 0, too much effort, (and impossible?)


I am sorry in advance if my questions are stupid ones, maybe the right answer is "it depends" (as always).

PS: I hate PC games, if I want to play I take my mountainbike or my snowboard out. Workstation (no games) research leads to AMD TR, but if I look at the results in real life, it seems that the single core speed is still what makes the PC faster with the current software.   :-//
Recently I've got a hold of an old but working portable dvd player LG DP450. I intend to use the lcd screen as a display for raspberry pi.
The interface on that LCD isn't compatible with the Raspberry Pi at all so you won't be just wiring it up to the expansion header using the DPI peripheral. You're going to be spending far more money and time in designing + making an interface board than just buying a premade working LCD. You'll need to make or buy a compatible CCFL backlight inverter as well. If this is a learning exercise then go for it but be aware it won't be easy.

I don't know if the newer Pis still support a composite video out (320x240 ish) like some of the lower res displays still use.
Yeah. They all support composite video output still but the newer ones have the composite output in the 3.5mm TRRS headphone socket. The Zero boards have it on an unpopulated .1" header.
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