/var/www/restricted/ssh/stm32/www/stm32circle/ STM CircleOS forum / Mems Scope

Username:     
Password:     
             

Forum

# 1   2007-11-01 13:46:07 Mems Scope (project: Mems 1.1)

ThomasScherrer
Member
From: Denmark
Registered: 2007-10-29
Posts: 64
Website

Mems Scope (project: Mems 1.1)

hello I changed this project into a mems scope:
fell free to get it :
www.webx.dk/stm32/

my problem is I want more SPEED ??
how can I make the LCD_DrawPixel(plotX,plotY,0);
perform faster ?


Thomas Scherrer Denmark webx.dk

Offline

 

# 2   2007-11-01 15:23:25 Mems Scope (project: Mems 1.1)

dalewheat
Member
From: Dallas TX USA
Registered: 2007-10-10
Posts: 43
Website

Re: Mems Scope (project: Mems 1.1)

Thomas,

Do you really need to draw a single pixel?  Or are you wanting to draw a line of pixels?

I ask because writing to the LCD involves a certain amount of overhead.  Each time you want to write data to the LCD you define a rectangle of interest.  Then you send the data.  If you're plotting single pixels, each pixel must be set up individually and this takes a small but cumulative amount of time.  If you're wanting to draw a horizontal or vertical line, or even a rectangular area, you can set up the area of interest and just dump the data, two bytes for each pixel.

Thanks,

Dale Wheat

Offline

 

# 3   2007-11-02 11:12:16 Mems Scope (project: Mems 1.1)

ThomasScherrer
Member
From: Denmark
Registered: 2007-10-29
Posts: 64
Website

Re: Mems Scope (project: Mems 1.1)

ok now I isolated the LCD_DrawPixel(plotX,plotY,0);
into a huge loop function
I can now draw 30000 pixels/ sec !!
before it was 21 pixels/sec
so the normal OS project structure call the users functions with a timed delay,
I think this is to maintain button and mems and timers for our convinience.
so keep hi speed critical stuff inside your loop and dont go out of routine (back to OS)
before you are all done and happy :-)
I like the OS to perform ADC and other stuff, but I want to speed it up ??
is that possible to skip all the timer/system tick waits ?
so I can enjoy pure 90DMIPS performance ?


Thomas Scherrer Denmark webx.dk

Offline

 

# 4   2007-11-02 13:04:04 Mems Scope (project: Mems 1.1)

Francis
Administrator
From: France-Grenoble
Registered: 2007-07-09
Posts: 890

Re: Mems Scope (project: Mems 1.1)

The various services of the OS are called by the systick interrupt.
You could redirect the systick irq for your own use, and call only the services you  need.
Perhaps in the next OS version we could make these calls configurable...

Offline

 

# 5   2007-11-02 13:25:20 Mems Scope (project: Mems 1.1)

ThomasScherrer
Member
From: Denmark
Registered: 2007-10-29
Posts: 64
Website

Re: Mems Scope (project: Mems 1.1)

good idea, and the speed of the gfx routines improved ?
and add the line draw routines to the standard libs,
so we can easyly draw lines from any point to anypoint :-)


Thomas Scherrer Denmark webx.dk

Offline

 

Board footer