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New module idea: Gadgeteer LRE (Long Range Extension)


#1

I mentioned in another thread that I had an idea for a module that would make it easy to extend a module several feet. Basically the module is a Gadgeteer 10-pin connector connected to a DB9. If you count the shield drain a DB9 cable has ten wires. This will allow one to use a standard DB9 cable to extend a module.

Here is the first go at the board layout.


#2

Good idea, just be careful with null cables.


#3

Nice! It will be interesting to see just how long a cable can be for various sockets/protocols. I’m assuming that’s a female DB9 connector? Let me know when you’re ready to barter or sell a couple.


#4

@ Gus: yes, a DB9 cable not a null modem or RS232 cable would be used.

@ ransomhall: it is a DB9 female. I may try to mill out a few test boards today.


#5

Today? Heck, I figured you would be getting a few fabbed via Laen or other service.


#6

Here is the first prototype board hot off the Taig mill. The board was designed in Eagle, exported as Gerber files and the Gerbers were imported into CamBam to create the tool paths. There is a free ULP for Eagle that will create the GCode for you but CamBam does a much better job at optimizing the tool paths. Total milling time for both sides was about 45 minutes.

Since the vias are not plated through they are placed so they are not hidden by a component and a small wire will be pushed through the hole and soldered from both sides.

This process works very well for small and prototypes like this. You can go from idea to a PCB in a few hours.


#7

That is a piece of art!


#8

Wow. Now I want the CNC machine sooner lol


#9

Very nice! What’s the thickness on the copper?


#10

It is 1oz copper so the thickness is 1.4mils. I believe I had the cutting depth set to 4mils.


#11

THAT is why I want a CNC! Very cool.

Do you apply solder mask or just leave it as-is?


#12

I milled out a few more boards today and soldered together a few boards. They work, but hand soldering in vias is a PITA! But, hey it is a small price to pay to go from idea to board in a few hours. The biggest challenge is getting solder to wick up the DB9 pins as the through holes are not plated. A slightly larger hole and lots of flux did the trick though.

On the second board I put together I was not paying attention and soldered the connector on the wrong side of the board! :-[

It turned out to be a happy accident though. I laid the board out intending to use a female DB9. It turns out you can mount a male DB9 from the bottom of the board and all the pin numbers work out correctly! :wink: This means you can use the same PCB with either connector.

I’ll fix up the silk screen to indicate which side of the board each connector type should be soldered from and then get a batch of them made up.This would be a good DIY board as there are only two components that need to be soldered on.

Edit: Forgot the image ::slight_smile:


#13

Cool! Show some pictures of the soldered module, please.


#14

Oops! Forgot to attach it :slight_smile: Added image to post above…


#15

Very nice! I’ll take a pair just like that :slight_smile:


#16

Here is a screen shot of the updated design. All the goodies are added to the silk screen and each side of the board is marked with the type of DB connector to attach from that side.


#17

Looks great!


#18

Ok. I just have to get off my butt and finish my shapeoko. inspired

Pete