Arduino & stepper 28byj-48

..there are tons of articles about this stepper..
..this is simplest solution i found.. there are few mistakes in the code, but i like it..

http://forum.arduino.cc/index.php?topic=85335.0

i did lol on whole thread how the guys grew up the code and made it far more complex
with weird function names for motor movement as well :-D
they forgot that Arduinos have only 2KB SRAM(most of units sold) for whole project
so we cannot spent huge part of it to make work single part :-D

the idea of the original code is far better than the complex mess from the coolguys..
its not generally wrong to use digitalWrite and its not necessary to use direct port manipulation like tha guys recommended because of the sequential type of the movement..

main problem of the original code is that there is attempt to be correct and make steps somewhat aligned to time with 4x digitalWrite in a row so it delays the desired change of state by variable but repeating amount of time :-D
correct is that there is just one change per the substep and make timing between these same way as datasheet says..
to be fine we must also introduce possibility to add sort of delay between the steps with all coils off as the original code makes stepper pretty hot after a while of high speed..

we should also care of full step and wave drive techniques so we can reach higher speeds than with halfsteps in the original code.. meh..

also i did get from 190 bytes of precious SRAM usage(serialPrint and so on) of the original code(not to mention the coolguys memory bombz lol) to 9 bytes (!) least for working code and 11 bytes in my „light“ version with no precise timing, just the steps and sort of „speed“ (aka delay) :-D
with timing mem usage is somewhat higher because of storing time variables as float type..
this can be partially lowered as we can fiddle with memory storing.. :-D

 

here is version 0.9.0 beta for testing.. eats 11Bytes of SRAM :-D
+ half steps both directions
+++ wave drive!!!
+ ability to set speed
+ full torque for testing

* be cautious with the testing full torque halfstep function, theres need to use stepper_sleep() func after >ending< sequence of these or even single step to turn coils off -> less heat.. its not used in demo code in loop() section. you have to add call to that func to test.. also its good to call stepper_sleep() before to ensure that all OUTs are LOW..

killa_stepper_demo_090.ino
10.4.2017 - 18.43
text/plain
10.47 kB

Arduino SPI RAM

..as i sometimes do run out of memory on my arduino projects i did search for some other options than reducing amounts of data used..

For example in my recent project with display a display buffer does eat 1024 bytes of 2048 bytes total so there is not much SRAM to work with for the rest of the sketch..

SRAM ICs:
23LCV512-I/P 64kx8bit SRAM  20MHz SPI
IP12B256I-TU 32kx8bit SRAM  20MHz SPI
IP12B512C-TU 64kx8bit SRAM  20MHz SPI

GOALS:
read/write operations with modified library
read/write simpler way directly from sktech, without library

update 29/3/2017: ICs ARRIVED!

Arduino OLED oscilloscope I

Arduino OLED Oscilloscope 1Arduino OLED Oscilloscope 2

..i wanted small portable oscilloscope for many years..
..found some parts, made some code.. and.. voila :-D

what:

  • based on Arduino, runs on all with 2kB SRAM or more
  • uses own modified Adafruit lib
  • own custom made menu with animations
  • can save values on SD
  • can send values over serial
  • serial monitor reacts to cls commands +can save output to SD
  • lots of options to set
  • tons of other batshit u will luv

modes:

  • single scope
  • dual scope
  • time collect
  • 1 to 8 channel bar meter
  • advanced serial monitor

——————————————————————
* still under development, current version is 0.99-2
* complete package with libs for download will be here soon.

 

DELL Optiplex 755 PSU fix

DELL PSU FIX 1

Friend who has a shop called me that his computer used as cash register has a black screen.. a PSU in oldish office computer have failed and been replaced by proper unit :-D
Worse thing is that i’m not able to fix the original one..

update 2/2017: the duct-taped PSU is still on top of the machine..

LAN over non-twisted cable experiment part.1

Yeah..

I was quite sure that this wont work, but we have been forced to try.. Not that much.. :-P
Normally the LAN is got over FTP and UTP cables, aka the twisted ones.. Yeah, the twisted wires.. Or even twisted pairs of twisted wires.. Cat6e has 6 twists per inch..
But using old 12 x 1.5mm² AC mains cable with no twists which is 20 to 30 meters long, is under ground and dated to late 70′s or 80′s must fail..or..?

LAN OVER NON TWISTED CABLE-1LAN OVER NON TWISTED CABLE-2LAN OVER NON TWISTED CABLE-3LAN OVER NON TWISTED CABLE-4

why this could work?
1st: i used only 10Mb/s mode
2nd: we were totally lucky

update 2/2017: i will be finishing this project soon!

New corporate system app

Last month i have been asked to code program to my work..
It took huge amounts of time.. but.. it was fun to hack Windoze :-D

what does it do:

  • after starting Win7 and login to username the desktop is not showed & our IS is started and held fullscreen
  • checks for our IS running, if its shutdown by user our app asks for pass or restarts it
  • hotkey to invoke our login / logout to system with timeout of 10min to login again
  • while user is logged in an unmovable & switchable window shows rest of time until next login window appears
  • checks for instances of web browsers (IE, Opera, Chrome, Mozilla) and asks for pass to our login or quits them
  • checks for instances of autoruns etc. and kills them so absolutely no way computer can be penetrated from local user
  • switching keyboard language via hotkey or automated because our IS needs EN keyset
  • is able to disable itself while certain user is logged in Win7 and enable again at logout
  • verbose logging to both local and remote files over network
  • ability to control TeamViewer QuickSupport executable and send its login over network  (dropped due to uncommon / unknown licensing until it gets clear)
  • overlay debugging window via hotkey

recent version 1.7.1.0 source code has size of ~30kB

GLXgears on various OS



..Windows may look quite good in chart, but gears were choppy and had huge tearing.. Linux based systems performed smooth with no vsync.. Nouveau driver has kinda slow 3D yet..