USB HID RELAY (LCUS_HID_X1) Windows software

HID Tester software for USB relay module.

Download Link.

Could not load file Microsoft.CodeAnalysis in VS Code

Possible fix for "... Could not load file or assembly 'Microsoft.CodeAnalysis, Version ..." 

In Visual Studio Code:
0. Switch to Terminal and go to your project folder.
Type:
1. "dotnet add package Microsoft.CodeAnalysis -v X.X.X" // make sure to add appropriate version
2. Press ctrl+shift+p, and type "OmniSharp: Restart OmniSharp"
3  Type (always like this):
   "dotnet restore <enter>"
   "dotnet build <enter>"

Wiring of bildge pump with buzzer and float switch

Buzzer works when pump is activated through float switch.

When pump is manually switched, it does not buzz.

(Components: Power PMOS, Power NMOS, bipolar NPN, resistors)

Link to falsad circuit simulation: http://tinyurl.com/yu6lbmbc

FT800 Chip programming

1. FT800 Embedded Video Engine Datasheet

2. Application Note, AN_240, FT800 From the Ground Up

3. FT800 Series Programmer Guide

Power consumption of SMD Leds

 

Brutal chess play by white player

White is short of queen and is making a brutal come back which results in black forfeiting.

Coupled inductors MAXIMA code

/* ------------------------------- CUT HERE -------------------------------- */

/* Current in Primary at time t

and coupling coefficient k */

m:float(1/1000);

i1_2nd_order(R1,R2,L1,L2,E,k,t):=block(

[

PrimCurrent:float(0.0),

A:float(0.0),

B:float(0.0),

C:float(0.0),

C1:float(0.0),C2:float(0.0),

Lamda1:float(0.0),Lamda2:float(0.0)],

A:L1*L2-k^2*L1*L2,

B:L1*R2+L2*R1,

C:R1*R2,

Lambda1:(-B+sqrt(B^2-4*A*C))/(2*A),

Lambda2:(-B-sqrt(B^2-4*A*C))/(2*A),

C2: -E*A*L2/((L2*L1-k^2*L1*L2)*sqrt(B^2-4*A*C))-Lambda1*E*A/(R1*sqrt(B^2-4*A*C)),

C1: -C2-E/R1,

PrimCurrent:C1*exp(t*Lambda1)+ C2*exp(t*Lambda2)+E/R1,

return (PrimCurrent)

);

/* example */

i1_2nd_order(0.3,12.5,1.5*m,0.8,12,0.95,1.2*m);

/* ------------------------------- CUT HERE -------------------------------- */

Ways to write quality software (to be updated)

- Comments should say what the code does, not how it does it.

- Name your routines so that they are self-evident. The same goes for parameters.

  That way, comments' necessity is reduced.

- Keep the number of parameters small. Try not to go over four. Tree to four is optimal.

- Try not to repeat the code.

- Avoid long routines of code.

- Avoid complex conditional statements with large blocks of code. Reduce the complexity.

 

** Refactoring (https://youtu.be/1KeJc6V4Jjk?t=127)

- Extract methods.

  Change long routines to few/many small ones (ca. 20 lines of code).

- Extract conditional and loop blocks of code as separate routines.

- Move related concepts closer together.

  Physically put similar parts/ideas (code that represent those) closer together.

- Reuse same parts of the code extracted earlier.

- Separate concerns/Modularity.

  Make each module (class/routine/...) do only one thing.

  Don't bloat/clog the code.  Goal is to achieve that one goal:)

- Work in small steps.

  Small changes are less prone to errors.

- When you code,try to refactor your code after every small change. Try to clean it up a bit if you can.

Remember: "Our job as programmers is to solve problems, not to write code":)

(source: https://youtu.be/1KeJc6V4Jjk?t=716)

##References: 

5 Ways to Improve Your Code, https://www.youtube.com/watch?v=1KeJc6V4Jjk,

Refactoring Legacy Code: STEP BY STEP

https://www.youtube.com/watch?v=p-oWHEfXEVs

https://www.youtube.com/watch?v=NCjwUptCaLU

https://www.youtube.com/watch?v=3iirETgRaRc

Bertrand Meyer:Object-Oriented Software Construction:

https://www.amazon.com/Object-Oriented-Software-Construction-Book-CD-ROM/dp/0136291554

Parametric variables in PSPice

To add parametric variable,use PARAM part from special.olb library.

Place PARAM part. Double click it. 

Below first tab is command button "New Property...". Click it.

Add parametric variable name and default value, click ok.

Close "Add New Property" window. Click "Apply", which is

next to "New Property...".

Next, in schematic, double click part value you want to make parametric.

I.E. for caps you can double click cap value, and type property name 

inside curly brackets, like {CapVal}.

Now, cap(s) with value {CapVal} will have capacitance you

put under (default) value in "Add New Property" window.

Sweeping is done under menu "Pspice"->New/Edit Simulation profile"->"Analysis", 

under options check "Parametric Sweep". Select "Global Parameter". Under "Parameter name:" type variable name without brackets. Under "Sweep type" select type:linear,logarithmic or value list.

PSpice VPULSE component parameters

Negative Voltage Load Switch

[1]

[2]

References:

[1] http://www.zen22142.zen.co.uk/Circuits/Switching/negative_switch.htm

[2] https://electronics.stackexchange.com/questions/97153/nmos-fet-with-a-negative-drain

Single pole dual throw switch PSpice model

Orcad Capture symbol plus Orcad PSpice model for

SPDT switch.

Thanks goes to HappySeeker from orcad.pe.kr

Link: http://setrst.byethost10.com/_blog/SW_SPDT.zip

Harmonic Identities

Asin(x) + Bcos(x) ≡ Rsin(x + α)

Asin(x) – Bcos(x) ≡ Rsin(x – α)

Acos(x) + Bsin(x) ≡ Rcos(x – α)

Acos(x) – Bsin(x) ≡ Rcos(x + α)

R=√(A^2+B^2) ; α=arctan(B/A)

Air flow inside computer case

source:https://www.techpowerup.com/forums/attachments/upload_2016-1-18_13-56-17-png.71169/

Transformer resources and modeling the same

Links:

Chapter 12: Electric Transformer and Coupled Inductors
(from book Practical Electrical Engineering)

http://www.beigebag.com/case_xfrmer_1.htm

https://www.pspice.com/resources/application-notes/using-inductor-coupling-symbols

https://www.youtube.com/watch?v=dh-l8aWgRc4

http://education.ema-eda.com/iTrain/PSpice163/PSpice_lesson9.html

https://www.pspice.com/spice-model-ideal-practical-transformers

Wallpaper fix for kb4534310

This might work for all of you, with missing wallpaper.

Should work with stretched option as well.

Browse for image in question that you want to use as wallpaper.

Open it using Windows Photo Viewer. 

Right click on the opened image and click on "Set as desktop background".

That's all.

Microsoft released a fix for it, KB4539602 .

Get it here: http://www.catalog.update.microsoft.com/Search.aspx?q=KB4539602

Some Integral Formulas

\[\int\limits_a^b {\frac{{f(x)dx}}{{f(a + b - x) - f(x)}} = \frac{{b - a}}{2}} \]

(src: http://y2u.be/BfZObnTIsYk)

\[\int {{e^{ - (a + bt)}}} *\sin (wt + c) =\\  - \frac{{{e^{ - (a + bt)}}*\sin (wt + c + \arctan \frac{w}{b})}}{{\sqrt {{b^2} + {w^2}} }}\]

Wire sizes and current capability

Dot convention for inductors

How to fix driver installation problem "The system cannot find the file specified"

When installing driver under windows one might get error message

"The system cannot find the file specified".

Note: This comes often when installing ADB drivers. In this case it can
be because  winusb.sys file is missing from %SystemRoot%\system32\drivers
and/or %systemRoot%\INF folder. If you are missing winusb.sys from these
folders,search for this file inside %SystemRoot%\ . In case of multiple hits, take the

one with the latest version and copy it to above folders. (All found files will
probably be the same.)

To find the root of the problem open %SystemRoot%\inf\setupapi.dev.log

or setupapi.dev. Now, search for strings like "error","file",

"The system cannot find the file specified", "0x00000002" (Error code for missing file).

Read thru the .log file carefully and look for errors and path/files

referenced.

Keywords: driver installation, failed, adb, install, file not found, Android

"The system cannot find the file specified"