New SMT Layout

[Matt_Edwards]

Guys there was some talk of a new Layout for a SMT version of the Grinch.

Is there still a need for one?
I am willing a able to give is a bash.

we would need to define what changes are required? any improvements? etc

• RPM's current Resistors come to mind.
• I would like to put a snap off section so you can operate as a 32 ch board.
• Another idea would be to add DIL pins pads so the chips can also be mounted on individual SOIC to DIL adapters. this will allow those not confident to repair SMT to use IC sockets and male Pins

So over to you. is there a need?

[g2ktcf]

just curious...with most computers now lacking a parallel port...is this really the way to go?

Not judging...just asking.

[RPM]

Originally Posted by Matt_Edwards

Guys there was some talk of a new Layout for a SMT version of the Grinch.

Is there still a need for one?
I am willing a able to give is a bash.

we would need to define what changes are required? any improvements? etc

• RPM's current Resistors come to mind.
• I would like to put a snap off section so you can operate as a 32 ch board.
• Another idea would be to add DIL pins pads so the chips can also be mounted on individual SOIC to DIL adapters. this will allow those not confident to repair SMT to use IC sockets and male Pins

So over to you. is there a need?

My only thoughts at the moment are:

1) Use the larger SOIC package for easier soldering

2) Add the "RSET" current limiting resistors

3) Add at least a 100uF "bulk" filter cap to the board.

4) Maybe add a terminal block or some method other than the smallish .1" DC connectors on the current Grinch design for supplying 5VDC power to the board. These things are a pain to crimp, so adding a TB would make connecting it much easier.

5) Make adding DMX dimming an option Sorry, I couldn't resist

[P. Short]

Or, for power, perhaps a receptacle so that you can plug in a 5VDC wall-wart, something like the mouser p/n 806-KLDX-0202-A. And, sorry to say, perhaps a provision for a diode to lower the input power voltage. Or, alternatively, provision for an LM317-style adjustable regulator.

[Matt_Edwards]

receptacle so that you can plug in a 5VDC wall-wart

Yep that is a good suggestion only issue I see is 2.1mm or 2.5mm? the use the same footprint so added to wish list.

provision for an LM317-style adjustable regulator

Added to wish list.

larger SOIC package for easier soldering

Added to wish list.

"RSET" current limiting resistors

Added to wish list.

Add at least a 100uF "bulk" filter cap to the board.

This one goes hand-in-hand with Regulator. Added to wish list.

add a terminal block .. for power

Added to wish list.

[Spadinator]

I soldered up an old plug in power supply from a zip drive to my grinch board for power and it works fine.

[RavingLunatic]

I'm not sure if a SMT version will allow the Grinch to remain the beginner's board that it is normally viewed as.

But if you are intent on doing it:

Instead of worrying with a variable voltage regulator, how about just adding in some signal conditioning for the LPT signals so you don't have to lower the operating voltage to the chips?

[P. Short]

That sounds better than the 317 trick, although it might still be a good idea to have an on-board regulator.

[Aurbo99]

Originally Posted by g2ktcf

just curious...with most computers now lacking a parallel port...is this really the way to go?

Not judging...just asking.

Thats a good question!

Never forget your roots.

Many systems these days no longer offer Parallel ports, correct. But there are oodles of systems sitting on GoodWill, S.A. and other trailing edge markets that offer such systems very very cheaply.

Ignoring the LPT port for older, cheaper systems would effectively exclude many potential members along the same lines as requiring a $28,000 CNC machine to learn how to do garage CNC milling.

Many Laptops these days also are devoid of Serial ports and only 1 or 2 USB's, soon to be completely gone as well as bluetooth or other wireless I/O becomes dominant.

Just because "Your" system does not have something does not mean we can forget about those I/O's and consider them obsolete.

Encouraging others into this hobby is a main source of where we gain new ideas and new ways to approach new and old methods.

We "could" evolve into an exclusive group where you require a minimum system level, a specific methodology or technology to interface with, and the minimum income level to support it. Or we can remain an open concept group that welcomes other ideas that don't require a rigid control of what could be accepted as new.

When I started, I came here and found the Grinch and said to myself, "Myself!, I can build that. Its cheap, easy to understand and hook up, give it a go"

Since then, I've move up to Renards, FG's and I've begun creating other devices and alterations to existing hardware. Not everyone will use what I present, but its out there for others to try, modify and improve on.

Many others here have followed similar paths, we owe it to ourselves and others following to maintain as many avenues into this hobby as possible. It has and will continue to create opportunities that go beyond our Blinky-Flashy community.


Never forget your roots

[P. Short]

The question is whether the Grinch using SMD parts is going to be a suitable candidate for an entry-level system. As such, it has to be perceived as easy and straightforward to build and use. For someone with some experience it is easy, but I don't think that a newbie would necessarily view it as safe. Especially since there will always be a number of people from the year before who have had problems, especially with soldering and the difficulty of swapping/removing parts.

My candidate for an entry-level board would be a simplified version of Macrosill's 595 coop board, still using DIP parts (or perhaps even that board). The simplification could consist of the removal of the LEDs, and reducing it down to eight channels.