Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

GS1903 still Problems #739

Open
Pfannex opened this Issue Feb 19, 2019 · 8 comments

Comments

Projects
None yet
2 participants
@Pfannex
Copy link

Pfannex commented Feb 19, 2019

Hi,

for my drawer lights I want to run my GS1903 led strip with the fastLED library. A ESP8266 is used as controller.
Generally the wiring and the simple sketch runs.
The GS1903 is fired with 12VDC, the data pin is directly connected to the ESP8266 GPIO 5.

I use the work around with the WS2812B model. #684
But I´m not able to controll the GS1903 stable.
Sometimes it works sometimes don´t.

For me it looks like communication problems, may be sometimes some bits are missing / wrong?
Or timing problems?

Can I run some further tests?

greetings
Pf@nne

@focalintent

This comment has been minimized.

Copy link
Member

focalintent commented Feb 19, 2019

It’s possible that you need a 5v level shifter on the data line.

@Pfannex

This comment has been minimized.

Copy link
Author

Pfannex commented Feb 21, 2019

OK, with the level shifter the communication runs quite better, but not error free. It looks like that there are still some bits missing / corrupted.
Does a video helps for solving the problem?

With a WS2812(b) (5VDC) I did not have any problems.

@focalintent

This comment has been minimized.

Copy link
Member

focalintent commented Feb 21, 2019

I found something claiming to be the data sheet for it - and according to the timings in there, SM16703 has the same timings 300/900us for a 0 and 900/300us for a 1) - so try SM16703

@focalintent

This comment has been minimized.

Copy link
Member

focalintent commented Feb 21, 2019

Also it has a really short reset time - only 40us - so try disabling interrupts if you are still seeing it be off.

@Pfannex

This comment has been minimized.

Copy link
Author

Pfannex commented Feb 21, 2019

After digging a while, I also found a chinese datasheet and can confirm the timings.

I will test the SM16703 when I´m home.

What do you mean with disabling interrupts?
ESP8266 interruppt or is there a interrupt functionallity within the fastLED-library?

Thanks for your quick support!
And sorry for asking about that simple problems.
I did not spend enough time in changing the controller from WS2812b (works out of the box) to the GS1903.
I run all my software and breadboard test with the WS2812b.
Only to reduce the current I change to the 12VDC GS1903.

That is most provoking, because my PCBs are in shippment and no level shifter is present......

greatings from Hamburg
Pf@nne

@Pfannex

This comment has been minimized.

Copy link
Author

Pfannex commented Feb 21, 2019

I got only a 16Mhz logic analyzer (resolution 62,5ns) but I think SM16703 HIGH/LOW-timing is OK.
But what about the reset time, the datasheet below shows 40µs.
The measured time is 1,5µs.
But with this gap (40µs / 1,5µs) shouldn´t run at any time?

sm16703
gs1903_datasheet

@focalintent

This comment has been minimized.

Copy link
Member

focalintent commented Feb 21, 2019

The reset time is how much time there needs to be between frames not between individual bits/pixels.

@Pfannex

This comment has been minimized.

Copy link
Author

Pfannex commented Feb 23, 2019

After rewiring and minimalizing my breadboard setup everything works as expected!
Also controlling the GS1903 with a ESP8266 GPIO level of 3V3!
So no level shifter is used.

What is the actual timing of the GS1903 (WS2812B)?
T0H=400ns / T0L=850ns; T1H=800ns / T1L=450ns; res>50µs?; tolerance +-150ns

I think the timming is a little bit different to the searched GS1903 datasheet?
T0H=300ns / T0L=900ns; T1H=900ns / T1L=300ns; res>40µs?; tolerance +-50ns <- much less
So maybe some GS1903 will not run errorfree.

imho adding a real GS1903 makes sense.

thanks for you support an great library!

greatings
Pf@nne

img_2183

WS2812B datasheet
ws2812b

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
You can’t perform that action at this time.