Search found 386 matches

by Deouss
Thu Apr 11, 2019 12:33 pm
Forum: Showcase
Topic: I2S-parallel example: Drive a 64x32 display
Replies: 60
Views: 35166

Re: I2S-parallel example: Drive a 64x32 display

I was trying to find out what performance (fps) was achieved displaying on that panels. Couldn't see what is actually a best technique for non-flicker and full 24bit RGB (or more?) lights. That fastled library looks very chaotic and seems to be using only RMT for esp - for ATMega all is time-aligned...
by Deouss
Wed Apr 10, 2019 3:19 am
Forum: General Discussion
Topic: WS2812B - timings and accuracy
Replies: 3
Views: 632

Re: WS2812B - timings and accuracy

So I just investigated all those timings a little and I am able to use a simple SPI to fully control WS2812B 32*8 led matrix. It is very simple and it seems like those timings are based on 1:4 ratio to 'lowest 0 high' ) Therefore 1 rgb bit of led is half a byte so one full rgb pixel is 12bytes - sti...
by Deouss
Tue Apr 09, 2019 3:48 pm
Forum: General Discussion
Topic: WS2812B - timings and accuracy
Replies: 3
Views: 632

WS2812B - timings and accuracy

So I am reading the documentation of WS2812B and see that sometimes they list different timing values f.ex. T0H - 4us and 0.35us in othes docs T0L/T1H - 0.8/0.85us and 0.9us. I am not sure what's going on and how those leds are properly controlled with what timings? Are there some min/max values or ...
by Deouss
Mon Apr 08, 2019 5:41 pm
Forum: General Discussion
Topic: RTOS running on one core only
Replies: 32
Views: 3901

Re: RTOS running on one core only

Yes) All that you mentioned here are nice computer science definitions that are hard to achieve perfectly working in real world :) I can tell you from experience - any tricks as those cooperative manipulations with ported or structurally incompatible code - they lead to serious conflicts and future ...
by Deouss
Mon Apr 08, 2019 11:50 am
Forum: General Discussion
Topic: RTOS running on one core only
Replies: 32
Views: 3901

Re: RTOS running on one core only

Well you are playing with performance levels and want to achieve fast as you call 'task switching'. Why don't you reverse engineer xTaskCreate...() functions into ASM because those are thread context switching subroutines and they are not optimized the custom way you want here. Or maybe just write y...
by Deouss
Sat Apr 06, 2019 1:44 am
Forum: General Discussion
Topic: RTOS running on one core only
Replies: 32
Views: 3901

Re: RTOS running on one core only

I am not sure how you define OS but it is operating system that should manage both cores efficiently and seamlessly. That CoopOS what you call is a thread that tries to be isolated from the tasks and memory and must watch not to overlap with any register or pointer values and that's quite shaky envi...
by Deouss
Fri Apr 05, 2019 8:55 pm
Forum: General Discussion
Topic: RTOS running on one core only
Replies: 32
Views: 3901

Re: RTOS running on one core only

I have never heard about such idea. It is impossible. You are mistaking multiple cores with multiple OSes. There always will be conflict unless one OS is hosted in VM within the other. Why even people talk about such difficult ideas and they want it to run on tiny humble MCU ) It is a bit ridiculous...
by Deouss
Fri Apr 05, 2019 1:01 pm
Forum: Hardware
Topic: Driving an 8-bit parallel 8080 bus using I2S
Replies: 25
Views: 4275

Re: Driving an 8-bit parallel 8080 bus using I2S

I am not expert but if you look at rtc_clk_apll_enable() code ( https://github.com/espressif/esp-idf/blob/master/components/soc/esp32/rtc_clk.c line 238) it seems like that function sets some I2C registers only. Setting proper clock for I2S may require manipulation of I2S_CLKM_CONF_REG or so. When I...
by Deouss
Fri Apr 05, 2019 12:04 pm
Forum: Hardware
Topic: Driving an 8-bit parallel 8080 bus using I2S
Replies: 25
Views: 4275

Re: Driving an 8-bit parallel 8080 bus using I2S

I was using modified code of this example
https://github.com/bitluni/ESP32Lib/blo ... 2S/I2S.cpp
But I must check again with 16 and 24bit lcds.
I would also check out reference manual how to set I2S properly

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