DMX board for Quickstart

skylight

Does anyone know if a DMX I/O board for controlling lighting has been made for the Quickstart? I've seen the DMX objects in the OBEX but wondered if anyone knows a source for the hardware compatible with the Quickstart? I don't have the facilities to make a board myself.

lanternfish

hi skylight.

I have made a number of DMX boards that I can interface to either the Quickstart or any other Parallax offering. And it is all done on protoboard or strip board. Very easy as there are plenty of DMX interface circuits on the interweb that you can use.

Does this help?

skylight

Thanks lanternfish, It's funny how you don't think of the solutions available at the time when posting, It's a simple circuit really looking at the object I just didn't think of what you suggested.

One thing with the protoboards is the concept, do they have strips on the back like strip board or are they just a matrix of holes? If the latter how are multiple connectons achieved, do components legs bend to one point at the back and soldered together or is it a wire wrap and/or solder bridge solution?

Edit I investigated the parallax protoboard for the quickstart and there was a diptrace layout which I used to get a 3D image of to rotate, some tracks are there but the prototyping area is mainly just holes,so if I were to use IC's for instance I'd solder a base and then wire to the legs with multiple wires or take component legs to the pins? or is there a simple way of creating strips with these boards to convert to strip board ie is there enough gap between hole rows to lay a bare wire? It does seem to be a bit cumbersome or am I getting the concept wrong? Is there a tutorial somewhere on the Parallax site using these boards?

Sorry to ask such a dumb question but i#ve never used a protoboard before

RDL2004

I like to first lay out the circuit in Diptrace (or whatever) trying to keep it as much as possible all on one side. It helps a lot if you keep things simple and make all connections in straight lines When I make the circuit on the proto board, I use 24 gauge wire with the insulation removed to form the "traces". Tack it down with a bit of solder near any bends that are far from a connection point or in the middle of long runs. If you need to jump one connection over another, either use the other side, or a use piece of wire that still has insulation on it.

Basic Propeller circuit on a proto-board




edit: You can use the leads of things like LEDs and caps like wire. Don't twist wires or leads together, just use solder like glue and try to only have one connection per pad (not three or more wires or leads coming together). It's easier to solder this way and makes repairs or modifications much easier. Make sure everything is clean and shiny before starting to solder.

skylight

Thanks Rick for the photo it's better than any explanation and I get the idea now! With careful planning adjacent holes can be used to strengthen/stabilise the tracks with a blob of solder here and there allowing for multiple connection points.

Although it may not be good practice the holes are close enough to bridge with solder too to make tracks, of course i'd make sure that any components legs were through the board first before making the bridges.

Much obliged for the information.

localroger

RDL2004 does a great job of showing how to use such a protoboard but don't forget that the Parallax protoboard isn't entirely naked holes; there are a few interconnections, which are silkscreened (but easy to overlook). Each Prop pin and corner power hookup has two connected pads, and there's a row of ground pins opposite the edge with the VGA and PS2 connector pads. Here's a little project I did...

Duane Degn

skylight wrote: »

Although it may not be good practice the holes are close enough to bridge with solder too to make tracks,

Besides having to worry about the bus traces localroger mentioned, many of Parallax's proto boards also have a ground plane. If you make a solder bridge over part of the ground plan you run the risk of shorting your connection to ground. Even a little too much solder on a pin can cause a short to the ground plan (ask me how I know). The solder resist isn't always solder proof.

I'd avoid having any solder make contact with an area of the board that may have a gound plane.

skylight

Duane Degn wrote: »

.....................I'd avoid having any solder make contact with an area of the board that may have a gound plane.

That handy to know and wasn't obvious from looking at the board, so it pays to lift "tracks" slightly above the board solder resist to avoid burning through?

Duane Degn

skylight wrote: »

That handy to know and wasn't obvious from looking at the board, so it pays to lift "tracks" slightly above the board solder resist to avoid burning through?

If the board has a ground plane, I use insulated wire when making connections. I often uses a little piece of heatshrink tubing if there's some bare wire I'm afraid may eventually cause a problem.

A lot of proto boards don't have a ground plane. The board Rick showed in post #4 doesn't have a ground plane so running a length of bare wire isn't a problem.

localroger

I use bare wire for short "runs" if it's stiff enough to have no chance of shifting and shorting to something else. The Parallax Protoboard does have a ground plane but it also has a solder mask, so simple mechanical contact is unlikely to form a short; however, dragging solder across could burn off the solder mask and create a connection. For cross-board runs I use insulated wire. Solid core telephone wire (as in the picture I showed above) works really well for this.

NWCCTV

Can someone post a picture of where this " Ground Plane" is so I know what you are talking about?

RDL2004

Look on the bottom of the Propeller proto board. You will see that under the soldermask it is two different shades of blue. All the lighter area is where there is copper. The darker area (and there's not much) is where it's bare PCB material under the mask. The holes and traces are basically just surrounded by a thin gap where there's no copper to insulate them from each other.

Duane Degn

NWCCTV wrote: »

Can someone post a picture of where this " Ground Plane" is so I know what you are talking about?

This the best picture I could find among those in my "manage attachments" folder.

This is the bottom of a Propeller Protoboard. You can see the traces for rx, tx and reset running across the bottom or the board. I scraped solder resist of the traces to add a header for a Prop Plug. (This was originally a USB protoboard but I cut the USB part out to use as a Prop Plug.) Between the traces the blue is a slightly different color than other areas of the board since there isn't any ground plane between these traces.



The seven holes on the bottom left of the picture show the holes being connected to the ground plane.

Here's a small piece of bare protoboard.



The large holes around the edge don't have the ground plane around them. You can see how the board on the left of the picture is a little thicker than the board on the right. If you look closely you can see the side copper on the left side.

The rest of these are more of my DIY Prop Plug.