Search found 829 matches

by pik33
Wed Feb 20, 2019 4:55 am
Forum: Graphics
Topic: How to set framebuffer properties flags
Replies: 5
Views: 87

Re: How to set framebuffer properties flags

I tried to enable alpha channel in Ultibo fb and nothing worked until I added proper lines to config.txt.

viewtopic.php?f=10&t=1248
by pik33
Sun Feb 17, 2019 10:42 am
Forum: Discussion
Topic: zero wired connectivity
Replies: 5
Views: 127

Re: zero wired connectivity

Some time ago I bought this hat:

https://kamami.com/extension-modules-fo ... b-hat.html

The hat has 4 port USB hub connected to RPi Zero USB and UART to USB converter. The UART USB output also powers the RPi so only one cable is needed to run this.
by pik33
Sat Feb 09, 2019 10:25 am
Forum: Discussion
Topic: Tricks and hints
Replies: 12
Views: 546

Re: Tricks and hints

This thing was hard to find so I pasted it here. Add $7F101000 to get a clock register address. The surce: https://elixir.bootlin.com/linux/v4.9.12/source/drivers/clk/bcm/clk-bcm2835.c#L112 #define CM_PASSWORD 0x5a000000 #define CM_GNRICCTL 0x000 #define CM_GNRICDIV 0x004 # define CM_DIV_FRAC_BITS 1...
by pik33
Fri Feb 08, 2019 8:20 pm
Forum: General
Topic: Code optimization tricks
Replies: 7
Views: 169

Re: Code optimization tricks

An example from my project : ( https://github.com/pik33/ultibo_retro_gui ) Seems to be necessary as r0-r3 can be used without this. I found this end syntax somewhere in fpc tutorials in this year (2019) - SimpleAudio code is earlier - and I stll didn't test it in most of my procedures, as they work ...
by pik33
Wed Feb 06, 2019 8:18 am
Forum: General
Topic: Code optimization tricks
Replies: 7
Views: 169

Re: Code optimization tricks

I thought I have to tell the compiler what registers I use in 'end' line of the asm code. Before I discovered this, I used push/pop

R11 can not be used if you want to access pascal variables in asm code.
by pik33
Wed Feb 06, 2019 8:16 am
Forum: Discussion
Topic: Threads and Processors
Replies: 124
Views: 11873

Re: Threads and Processors

Is it possible to configure dedicated cpu(s) at the very start of the system: to tell the scheduler to not allocate any threads to selected cores so you don't need to move them later?
by pik33
Tue Feb 05, 2019 5:14 pm
Forum: General
Topic: Code optimization tricks
Replies: 7
Views: 169

Re: Code optimization tricks

Try to set optimization level 3 or 4 instead of default 2 and check if something changed.

This version of fpc for ARM is far from being optimal, but you can always insert some asm code in time critical sections.
by pik33
Sat Feb 02, 2019 11:58 am
Forum: General
Topic: Delays and thermal management
Replies: 16
Views: 411

Re: Delays and thermal management

what could 10,000Hz be good for?


Software based pwm :) to control something without switching off the sound
by pik33
Sat Feb 02, 2019 7:17 am
Forum: General
Topic: Delays and thermal management
Replies: 16
Views: 411

Re: Delays and thermal management

A very useful modification.
by pik33
Wed Jan 23, 2019 6:48 am
Forum: Discussion
Topic: microbit as ultibo peripheral
Replies: 72
Views: 3759

Re: microbit as ultibo peripheral

Do not Compile C compilers on uSD cards on PI's it takes hours and days of doing that wears out uSD cards.


I killed 2 (cheap) SD cards while recompiling Lazarus from the source.

Go to advanced search