Dmx512

[lpcware]

Content originally posted in LPCWare by serge on Wed Oct 05 00:01:01 MST 2011
I was searching this forum for threads on DMX512 but was not able to find any.
I have a small new project to connect a DMX512 signal to a USB port for a small local theatre company. It seems someone has a problem with cables and has to check if the data is readable at the end of the line.
The full standard can be BOUGHT from USITT or ESTA FOUNDATION but I hope to conclude this very small project (A LPC1343 f.e. with very little extra components should do the trick nicely) without having to buy the spec's. I know there is always wikipedia...
So now my question, is there anybody out there who has already some DMX512 (A) experience in combination with an LPC MCU?

Thanks in advance,

Serge

[lpcware]

Content originally posted in LPCWare by Shezi71 on Fri Jan 13 03:07:54 MST 2012
Hello NXP_Europe,

Could you please explain me how the DMX512 receiver protocol detects Mark after break (MAB) in AN10717 application note?

[lpcware]

Content originally posted in LPCWare by Shezi71 on Thu Jan 12 08:22:42 MST 2012
Thank you. Have you tested that code on ARM7? The receiver module is not well written in this application note.

[lpcware]

Content originally posted in LPCWare by NXP_Europe on Thu Jan 12 07:12:38 MST 2012
Hello Serge,

There is an Application Note written by NXP, but (...!) this was written for the ARM 7 (LPC2000) ...I think it can be used as basis.

see:
http://ics.nxp.com/support/documents/microcontrollers/?search=dmx512&locale=en%2C%2CLatn&type=appnot...

[lpcware]

Content originally posted in LPCWare by Shezi71 on Thu Jan 12 02:14:45 MST 2012
Thank you for your reply. Can you able to provide me some kind of algorithm or flow chart of the software? I developed my project on LPC1114 and DMX512 protocol is the only thing I am struggling with. Please help!!

[lpcware]

Content originally posted in LPCWare by serge on Wed Jan 11 00:29:58 MST 2012
My project has been on hold for a while and it seems that it won't be continued before may 2012. The reason why it is on hold is that the scope of the project has been althered. We will port the already existing but not finetuned code to the LPC1769 to have 3 DMX512 channels (+ 1 receiver to test for bad cables for example) controlled by USB (only one DMX channel to be compatible with Freestyler) and/or ethernet ip v4 and ip v6. The 3 channels will only be available with a pc-program via the ethernet interface. I don't intend to write a ethernet IPV6 stack myself. I don't consider myself able to do such a thing.
So after i get the green light i will do a search to see if i can find a ethernet ip v6 stack under a GPL license. If not ... too bad but then my client will be stuck with ip v4.
This means that i won't have sample code before may or june at the earliest.

Maybe that i could post a DMX512 example code when this project is finished.

[lpcware]

Content originally posted in LPCWare by Shezi71 on Tue Jan 10 09:57:31 MST 2012
Hi,

I am working on LPC1114 microcontroller and I am looking for any DMX512 application note written for it. Is there any application note or source code for M0 cortex microcontroller?

Thanks

[lpcware]

Content originally posted in LPCWare by serge on Wed Oct 05 03:31:41 MST 2011
[FONT=Arial]Hi OXO,[/FONT]

[FONT=Arial]I never said that it was going to be complicated that is why i call it a small project.[/FONT]
[FONT=Arial]But I know that they recently added a checksum and SIP to the DMX512 standard. I guess i won't need it right now but somewhere in the future i know that they will ask me to update te firmware so i want to be prepared for those new functions. Also fairly small theatre companies tend to buy new stuff :p.[/FONT]
[FONT=Arial]Just like you said it should be very simple. It is, up to recently, a one way protocoll without any means of error-checking.[/FONT]
[FONT=Arial]I was just thinking that i could add a oled display so that for so that for simple testing they wont need a pc.[/FONT]

[lpcware]

Content originally posted in LPCWare by serge on Wed Oct 05 03:28:02 MST 2011
Hi OXO,

I never said that it was going to be complicated that is why i call it a small project.
But I know that they recently added a checksum and SIP to the DMX512 standard. I guess i won't need it right now but somewhere in the future i know that they will ask me to update te firmware so i want to be prepared for those new functions. Also fairly small theatre companies tend to buy new stuff :p.
Just like you said it should be very simple. It is, up to recently, a one way protocoll without any means of error-checking.
I was just thinking that i could add a oled display so that for so that for simple testing they wont need a pc. I have a [SIZE=3]DENSITRON - DD-160128FC-1A , 160X128 display ready in my box. Only it is a 2.8V thingy, so i need to figure out if i will damage it or not when connecting to a 3.3V supply. Densitron said it will work in the range 2.4 to 3.3 volt. But what happens when, for some unknown reason the voltage rises to 3.4... especialy during power-up or -down.[/SIZE]

[lpcware]

Content originally posted in LPCWare by OXO on Wed Oct 05 03:04:15 MST 2011
Serge,

It all looks rather easy. You could get the code together in a couple of hours I think.

http://www.ubasics.com/DMX-512