Author Topic: Getting DMX out of the FPP/Pi  (Read 7900 times)

Offline algerdes

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Re: Getting DMX out of the FPP/Pi
« Reply #15 on: November 12, 2015, 09:13:10 AM »
Thanks Chris.

I'll look into smaller.  At least I have a working solution for the show opening in a week.   :o
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Offline AAH

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Re: Getting DMX out of the FPP/Pi
« Reply #16 on: May 03, 2016, 10:28:50 PM »
Has there been any change to the ability of FPP to output DMX (via an RS485 chip) direct from GPIO15/Pin 15/TxD on a Pi?

I have tried using the Pi's onboard serial port for DMX and it doesn't want to cooperate although it did work for PixelNet.  I think the break required by DMX is throwing it for a loop.   You could use a smaller dongle than the lynx if you are tight on space.

Offline CaptainMurdoch

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Re: Getting DMX out of the FPP/Pi
« Reply #17 on: May 04, 2016, 07:57:34 PM »
The onboard serial has been tested to work fine for DMX, pixelnet, and renard with the latest FPP v1.8 code.  I had to change how we set the custom speed a few versions back and once I did that, I was able to successfully test DMX and pixelnet at their higher speeds.
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Chris

Offline patdelaney

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Re: Getting DMX out of the FPP/Pi
« Reply #18 on: May 05, 2016, 06:11:54 PM »
The onboard serial has been tested to work fine for DMX, pixelnet, and renard with the latest FPP v1.8 code.  I had to change how we set the custom speed a few versions back and once I did that, I was able to successfully test DMX and pixelnet at their higher speeds.


I just saw this, so are you saying you don't need a usb/485 dongle? If so what are the pins on the FPP that you used and will this be added to online help?


Pat

Offline CaptainMurdoch

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Re: Getting DMX out of the FPP/Pi
« Reply #19 on: May 05, 2016, 06:18:05 PM »
The onboard serial has been tested to work fine for DMX, pixelnet, and renard with the latest FPP v1.8 code.  I had to change how we set the custom speed a few versions back and once I did that, I was able to successfully test DMX and pixelnet at their higher speeds.

I just saw this, so are you saying you don't need a usb/485 dongle? If so what are the pins on the FPP that you used and will this be added to online help?

You still need a RS485 chip and any accompanying parts needed to power it properly.  The serial port on the Pi is not RS485.   The Pi 'hats' that have RS485 output on them have the RS485 chip on them.

Offline patdelaney

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Re: Getting DMX out of the FPP/Pi
« Reply #20 on: May 06, 2016, 07:31:04 AM »
OK that's what I thought.


Pat

Offline fartech

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Re: Getting DMX out of the FPP/Pi
« Reply #21 on: July 19, 2016, 09:52:50 PM »
The onboard serial has been tested to work fine for DMX, pixelnet, and renard with the latest FPP v1.8 code.  I had to change how we set the custom speed a few versions back and once I did that, I was able to successfully test DMX and pixelnet at their higher speeds.
I am unable to get a working DMX out via the ttyAMA0 port. Snooping with a scope on the serial side I am seeing nothing like an actual DMX signal. I am currently using Ron's board.
stty in the SHELL gets me this:
speed 0 baud; line = 0;                                                                                                                                                                       ixany                                                                                                                                                                                         tab3                                                                                                                                                                                          -echok

What am I missing?

Offline CaptainMurdoch

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Re: Getting DMX out of the FPP/Pi
« Reply #22 on: July 19, 2016, 10:26:54 PM »
I am unable to get a working DMX out via the ttyAMA0 port. Snooping with a scope on the serial side I am seeing nothing like an actual DMX signal. I am currently using Ron's board.
stty in the SHELL gets me this:
speed 0 baud; line = 0;                                                                                                                                                                       ixany                                                                                                                                                                                         tab3                                                                                                                                                                                          -echok

What am I missing?


Did you remove the "console=ttyAMA0,115200" entry in /boot/cmdline.txt?  I think we already comment out the getty running on /dev/ttyAMA0 in /etc/inittab, so that shouldn't be the issue.

Offline fartech

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Re: Getting DMX out of the FPP/Pi
« Reply #23 on: July 20, 2016, 01:15:24 AM »

Did you remove the "console=ttyAMA0,115200" entry in /boot/cmdline.txt?  I think we already comment out the getty running on /dev/ttyAMA0 in /etc/inittab, so that shouldn't be the issue.



I just checked both places and getty was commented out but console was still there.

Removing the console entry enabled the port as I can see data now, but it appears to be much slower than standard DMX.
It also wont work with any of my devices, but they do show that they are getting something.

Offline CaptainMurdoch

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Re: Getting DMX out of the FPP/Pi
« Reply #24 on: July 20, 2016, 04:01:54 PM »
Removing the console entry enabled the port as I can see data now, but it appears to be much slower than standard DMX.
It also wont work with any of my devices, but they do show that they are getting something.

Which version of FPP are you using?

Offline fartech

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Re: Getting DMX out of the FPP/Pi
« Reply #25 on: July 20, 2016, 07:05:51 PM »
I am using Version: v1.8-20-gaff9426.

My search lead me to http://fw.hardijzer.nl/?p=138

Set configuration parameters in /boot/config.txt:

init_uart_clock=16000000

Once I put that in DMX worked perfectly. Perhaps something got hosed from changing versions.

Offline AAH

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Re: Getting DMX out of the FPP/Pi
« Reply #26 on: July 25, 2016, 10:29:48 PM »
I was just testing the DMX output of my rPi-28D and noticed that it wasn't working as expected. I scoped it and the signals didn't look right and it wasn't talking to my DMX boards. I think it tested okay months ago and a lot earlier version of FPP but can't confirm 100%. I searched on here and that led me to this thread.
Can I get a noob guide to how/where to make that change to see if that solves my problem.
I should imagine that the clockrate will affect the timing but when I scoped the signal the MBB and MAB signals didn't look too much like what I expected. A correct clockrate will at least let me see if that fixes that part of the issue.

Offline fartech

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Re: Getting DMX out of the FPP/Pi
« Reply #27 on: July 26, 2016, 12:26:44 AM »
for both I did:
sudo nano /boot/cmdline.txt
remove the "console=ttyAMA0,115200" and save.

sudo nano /boot/config.txt
Add "init_uart_clock=16000000" I thin I put it near the bottom and save.

In the end I just made the changes to the install package, and that was pretty simple too.

Offline AAH

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Re: Getting DMX out of the FPP/Pi
« Reply #28 on: July 26, 2016, 02:14:25 AM »
That's noob instructions?
I don't have a monitor or keyboard connected to my Pi and never have and I have no idea how to use Linux.


for both I did:
sudo nano /boot/cmdline.txt
remove the "console=ttyAMA0,115200" and save.

sudo nano /boot/config.txt
Add "init_uart_clock=16000000" I thin I put it near the bottom and save.

In the end I just made the changes to the install package, and that was pretty simple too.

Offline markrvp

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Re: Getting DMX out of the FPP/Pi
« Reply #29 on: July 26, 2016, 07:18:26 AM »
That's noob instructions?
I don't have a monitor or keyboard connected to my Pi and never have and I have no idea how to use Linux.


for both I did:
sudo nano /boot/cmdline.txt
remove the "console=ttyAMA0,115200" and save.

sudo nano /boot/config.txt
Add "init_uart_clock=16000000" I thin I put it near the bottom and save.

In the end I just made the changes to the install package, and that was pretty simple too.


From your PC go to the FPP status page in your Web Browser.  Under the first menu heading down on the list is a choice called:  SSH      Select that and it will open a window that is virtually the same as having a monitor, keyboard, and mouse hooked up to your Pi.  type in the command he gave you and make the changes listed.  Hope this helps.

 

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