LATEST RELEASE:  FPP 6.1 - Download from here -



Welcome, Guest.
Please login or register.
Forgot your password?

+-Site Stats

Total Members: 15524
Latest: fighteriris
New This Month: 32
New This Week: 20
New Today: 3
Total Posts: 127343
Total Topics: 15630
Most Online Today: 135
Most Online Ever: 7634
(January 21, 2020, 02:14:03 AM)
Users Online
Members: 9
Guests: 33
Total: 42

Raspberry PWM

Started by matys1701, October 30, 2016, 12:56:42 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.


Hello, I am new to FPP and I want to connect SSR board directly on GPIO pins, but it can go only high or low. Is there any way to use software PWM? Or how can I controll SSR board with FPP without external hardware? :-\ :-\


  Even if you work out the PWM ability you may have issues. Most SSR's have zero crossing for the turn off the the internal electronics. In order to get reliable dimming the circuitry should be detecting the incoming 50 or 60Hz mains frequency and should be dimming based on the zero crossings of the voltage. There's also a problem when dimming sine waves in that it's not a linear relationship between "on time" and output brightness. There's also a big difference between the brightness curves for LED and incandescent lights. Incand will heat up and emit light regardless of the voltage whereas LED doesn't emit light until you hit a voltage threshold which means that they are often dimmed only over a small portion of the mains waveform.
  It's complicated to try to get the correct results with mains voltage dimmers. That's 1 of the reasons I've never worried about building a mains voltage dimmer


FPP doesn't have any PWM channel output capabilities currently.  I have it on my (long) ToDo list to look at adding PWM capability to the GPIO Channel Output using SoftPWM in WiringPi, but haven't got around to it yet.  This would only work for DC SSR's I believe and is one reason I haven't looked into it so far.


Thank you a lot. Now I know what I can/can not do  :) ;)

Support FPP

+- Recent Topics

What am I doing wrong? FPP I’m ZCCP? by rudybuddy
Today at 09:01:26 AM

FPP Playlist by dkulp
Today at 07:14:42 AM

Setting up LOR to serial of F16v3 and configure in xLights by brmeadows
Today at 05:46:42 AM

FPP not releasing control to WLED when idle by Poporacer
December 06, 2022, 10:39:18 PM

1 player/2 remote by Poporacer
December 06, 2022, 08:07:48 PM

K8-PB Network Issue by Kensington Graves
December 06, 2022, 07:40:50 PM

Failed V1.03 diff receiver boards by bud29
December 06, 2022, 07:13:38 PM

XLights Variant by Poporacer
December 06, 2022, 06:56:52 PM

FPP Oddness. Remote not remoting, schedule not scheduling??? by Poporacer
December 06, 2022, 06:27:33 PM

Text inverted by dreiman
December 06, 2022, 06:12:17 PM

Powered by EzPortal
Powered by SMFPacks Menu Editor Mod