Using the UART pins on the Pi?

RavenII · Mon Aug 31, 2015 2:51 am

Hello all,

I'm currently using this wireless DMX PCB and it requires either an RS485 converter or an RS232/UART adapter and I'm currently using this here using USB but would like to eliminate the need for it by using the GND/5v/TX/RX that's built into the Pi, is there any way of doing this?

mcallegari · Mon Aug 31, 2015 2:51 am

RavenII wrote:I'm currently using this wireless DMX PCB and it requires either an RS485 converter or an RS232/UART adapter and I'm currently using this here using USB but would like to eliminate the need for it by using the GND/5v/TX/RX that's built into the Pi, is there any way of doing this?

Hi, I have implemented a UART plugin for QLC+.
Would you be willing to help testing it ?

RavenII · Mon Aug 31, 2015 2:51 am

mcallegari wrote:
RavenII wrote:I'm currently using this wireless DMX PCB and it requires either an RS485 converter or an RS232/UART adapter and I'm currently using this here using USB but would like to eliminate the need for it by using the GND/5v/TX/RX that's built into the Pi, is there any way of doing this?
Hi, I have implemented a UART plugin for QLC+.
Would you be willing to help testing it ?

YES!! Absolutely!

mcallegari · Tue Sep 01, 2015 8:01 am

Hi, at the moment there is no UART plugin for QLC+.
Might be coming soon though.

RavenII · Tue Sep 01, 2015 9:45 pm

Ah, I see, thanks a lot! I really appreciate the work and support!

mcallegari · Sat Sep 12, 2015 4:05 pm

So, here you go.

You need to do 3 things:
Add this at the end of the config.txt file in the SD FAT partition:

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init_uart_clock=16000000

Otherwise the UART will not support the speed requested by DMX which is 250kbps.

Edit the file cmdline.txt in the FAT partition and turn it into this:

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dwc_otg.lpm_enable=0 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline rootwait

These 2 will be included by default in the next images.

Then extract the attached ZIP file and copy the .so file in /usr/lib/qt4/plugins/qlcplus/
Restart QLC+ (or reboot) and you'll see the UART plugin.

Please report here your results.
Thanks

RavenII · Sun Sep 13, 2015 11:33 pm

Massimo....I love you. It worked flawlessly. I'll definitely post up what my setup consists of so people can know the power of this software. Dude, I've got a very functional DMX controller....wireless. Awesome.

mcallegari · Mon Sep 14, 2015 9:30 am

Excellent news Ramsin !
Yes, please post a bit of information of your setup as other users might be interested in it and can be sure that it works

karrika · Sun Oct 11, 2015 11:01 am

This is really good news. Does it implement DMX in also?

Once I get the isolated GPIO board done I would love to make an isolated DMX in/out board to the RPi.

mcallegari · Sun Oct 11, 2015 11:01 am

karrika wrote:This is really good news. Does it implement DMX in also?

Once I get the isolated GPIO board done I would love to make an isolated DMX in/out board to the RPi.

Unfortunately, no DMX input at the moment.
It's a programming pain in the ass.

bodex · Thu Jan 21, 2016 3:47 pm

Hi,

I tried to use the three UART-Pins as an Outpout-Device. But it doesn´t work yet. Must i change some configurations to use them?
What Baud Rate uses the UART Out.

Bodex

mcallegari · Thu Jan 21, 2016 8:28 pm

https://github.com/mcallegari/qlcplus/b ... et.cpp#L98

250kbps, to perform DMX output

Mihai Andrei · Fri Jan 29, 2016 4:57 am

I built UART converter :
chip used: SN75176B http://www.ti.com.cn/cn/lit/ds/symlink/sn75176b.pdf

chuddy117 · Tue Dec 20, 2016 4:47 pm

I just donated and received a link to the QLC+ image for the PI, and I'm looking to use the native UART pins on my PI, but am a little confused as to the components required. I have a MAX485 converter (same as this one: http://www.jonshouse.co.uk/rpidmx512.cgi), but on that website, it doesn't use the UART pins on the Pi. Does any one have a diagram for which pins are required, and if I need anything beyond the MAX485 adapter?

Mihai Andrei · Sun Jan 01, 2017 8:34 pm

I have done so and I works perfectly
is it of RPI QLC for OLA

1)
put before writing that is

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with the command:

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sudo nano /boot/cmdline.txt

2)
put the end of everything

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init_uart_clock=16000000

with the command:

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sudo nano /boot/config.txt

3)
simple .. just connect the RI uart TX for the Rpi .. and everything works
(Capacitors are used to overcome small disturbances from the DMX line)

the LED is not mandatory but as confirmation that everything works I put .. you can also put it to the test and remove it very important to be bi-color LED with 2 pins .. or inverted pin inside .. or 2 opposite mounted LED .. (then LED with 3-pin and common ground are not good)
the startup will be red .. while charging the image can change the color (flashing of LED type sd) then they are both turned on ..
as soon as you throw the signal you see flashing very fast (almost imperceptible) to 40hz ...
in this case, everything should work ...
We just have to try a real fixture to have more confirmation that everything is ok