1804 on PixAd8

[neilric99]

for reference the diyla smartstring controllers use a 120ohm resistor

 

[kane]

for reference the diyla smartstring controllers use a 120ohm resistor

Thanks Neil - handy that I happen to have those handy.

 

[kane]

I've changed over a couple of the resistors to 120ohm - given 1804 doesn't use the Clock line, I only changed the resistors over for the Data line - for two of the outputs.

Unfortunately it hasn't helped the situation. For now, I'm just using the inbuilt test sequences from the pixad8 - on the un-modified outputs, you get the test sequence, but on the modified outputs, the modules all light up in white, but don't change from there.

Oh well, will wait to see what Ed thinks!

 

[riri7707]

Hi Kane,
What happens if you sacrify the first chip 1804 placing him the shortest as possible after the output of the PixAd8 (2/3cm not more)?
Don't each module regenerates the clock and data from one to the next one?
I remember i do that with the 2801chips, where i had similar problems rear the TP last year
This solves the problem and found i can reach maximum 6 meters from 1st module to next one and so on.
But the first one direct attached to the TP for clock and data regeneration
Henri

 

[fasteddy]

Hi Kane,
What happens if you sacrify the first chip 1804 placing him the shortest as possible after the output of the PixAd8 (2/3cm not more)?
Don't each module regenerates the clock and data from one to the next one?
I remember i do that with the 2801chips, where i had similar problems rear the TP last year
This solves the problem and found i can reach maximum 6 meters from 1st module to next one and so on.
But the first one direct attached to the TP for clock and data regeneration
Henri

This is what i do with my TP3244 controllers and it works a treat

 

[kane]

Hi Kane,
What happens if you sacrify the first chip 1804 placing him the shortest as possible after the output of the PixAd8 (2/3cm not more)?
Don't each module regenerates the clock and data from one to the next one?
I remember i do that with the 2801chips, where i had similar problems rear the TP last year
This solves the problem and found i can reach maximum 6 meters from 1st module to next one and so on.
But the first one direct attached to the TP for clock and data regeneration
Henri

Yes, this definately works, and will probably be the solution for now. I just think that Ed would prefer it to get a bit more than 3-4cm to the first pixel!

I've actually worked out that I haven't broken the outputs my modifying them with a 120ohm resistor - they actually still work, but instead of working at any speed (1600,2000,2400), they only work at 2000 (which is actually the correct speed for 1804)

 

[kane]

Yes, this definately works, and will probably be the solution for now. I just think that Ed would prefer it to get a bit more than 3-4cm to the first pixel!

I've actually worked out that I haven't broken the outputs my modifying them with a 120ohm resistor - they actually still work, but instead of working at any speed (1600,2000,2400), they only work at 2000 (which is actually the correct speed for 1804)

Just a quick followup for anyone that is interested.

Ed will probably follow up with a more technical description, but it seems as though the 74LSxxx chips that are onboard (one for each of the two groups of four) cause issues with tm180x. I ordered some 74ACT541 to replace them, and now, I get 5m+ from the Pixad8 to the first pixel.

All TM180x gear I have (rectangle modules, square modules, pixel strings) are working well!

 

[Mike]

5m isnt too bad at all. Wonder if he will change the chip on the boards from now on.

 

[j1sys]

Yes, all future boards will be shipped with the ACT chips in place. we will also include the LS chips in a small tube for the rest of this season just in case there are some strings that work better with the LS chips.

I will be sending out replacement chips to all past purchasers in the USA and Canada and will work with someone in Aussie land to drop a set in the mail to all Aussies at our expense.

Henri, i think, is the only one in another country. I don't mind mailing it to him but it could take 3-4 weeks to arrive. They are only 75 cent chips (x2) and may be easier for him to pick up locally.

Ed

 

[kane]

I will be sending out replacement chips to all past purchasers in the USA and Canada and will work with someone in Aussie land to drop a set in the mail to all Aussies at our expense.

To be honest, easiest option would be for anyone here that needs them (which doesn't seem like there's a huge amount of us that are using TM180x), can just grab a couple online from RS Components:
http://australia.rs-online.com/web/p/products/1267399/
$0.61 each, and they do next day delivery anywhere in Oz for free.
Cheers
Kane

 

[Mike]

So what chip does the 6803 and the 2801 like better then?

 

[kane]

So what chip does the 6803 and the 2801 like better then?

I'm pretty sure Ed found that his test 6803 and 2801 lights all worked fine with either chip - the main difference was just for tm180x - it seems to require the ACT to work properly (I think in part due to being 12v)

 

[j1sys]

In my opinion the 74ACT541 is better for ALL string types. The CMOS output pulls the signal closer to the rails (0-5) than the LS version. At 5V for the 2801 and 6803 it has always worked ok with the LS. The TM180x and the 12v strings definitely work better with the ACT. But again, i don't want people to have a weird string that works best with the 74LS not work in the next two months as they put on their show.

-ed

 

[Mike]

ok so with the ACT chip are you getting increased range on all string types or just on the 18xx.

 

[riri7707]

Good news Ed,
No worries for me, i can manage locally and made the modifications on the boards.
I have a complete lab at home
I just need the "how to" and firmware for the TM.
Let me know...
Cheers...
Henri