DiyLightAnimation

Hardware => Lynx Splitter => Topic started by: pete peters on March 29, 2015,

Title: DMX Splitter Output Problem (Problem SOLVED)
Post by: pete peters on March 29, 2015,
Output four on my DMX Splittrer will not work.

Output 1, 2, 3  all work fine.

I have replaced the 485 chip,  Swapped it with other output chips,  I have  replaced the 8 pin socket. I have checked all the solder joints and re soldered the joints.  I have checked the boards foil traces and they check out OK.

I am stumped

Does anyone have any ideas??

Thanks  Much

Pete P
Title: DMX Splitter Output Problem
Post by: CaptainMurdoch on March 29, 2015,
There was a missing trace on these I believe.  I think it is documented in the build manual in the wiki.  I think I recall having to put a jumper wire on the one I had to get the fourth output working.
Title: Re: DMX Splitter Output Problem
Post by: dmaccole on March 29, 2015,
This is clearly the v1 of the DMX Splitter, as the v2/v3 have only three outputs.

And the reason that v1 was abandoned was because of frequent problems with Output 4 operating.

The blue transformers had limited output current and it turned out that they would not drive all four of the spec'd RS485 chips.

If you don't have ambient-air temperature issues, you might try using either this RS485 chip ...

http://www.mouser.com/ProductDetail/Exar/SP485RCP-L/?qs=sGAEpiMZZMtk5jbcouIbS0UPIAQjQwU7lvboiXMmK5o%3d

(Or this one if you're in Minnesota or similar: http://www.mouser.com/ProductDetail/Exar/SP485REP-L/?qs=sGAEpiMZZMtk5jbcouIbS2HlXy8NemZChIyzZOHiVTU%3d)

The illustrations are of SMD chips, but the metadata says they're through-hole.

It also says they only draw 500 microamps, which even times four shouldn't strain the blue transformer.

I make no guarantees.

\dmc

Title: Re: DMX Splitter Output Problem
Post by: pete peters on March 29, 2015,
Thanks Very much to both of you!!

I installed the jumper as shown in the wiki.

Now ALL 4 Outputs work!!!

I will also look at upgrading the chips as well.

THANKS Again!

Pete P