Build guide step #7

Build out of the boards is complete.  Josh did a fantastic job soldering all of the components in.  These look cool too!  Now it is on to testing.

We built a test rig to test these.

With them tested it is time to install them.

Made one modification to the back bracket.  Needed to notch out the aluminum to allow for for the larger cartridges that carry small button cell batteries inside them.

Next post we make slots in the bonnet to allow access to the cartridge slots.  Here is a start.

 

Build guide step #6

Finally etching the board and making real progress!  Here it is in my small test tank in a bath of sodium persulfate. This process takes 10 minutes.  If you need to fix some of the resist, clear nail polish works great!

Once etched you are left with your copper traces aligned to your holes and you are ready to go.  Now we cut them apart using a scroll saw and some patience.  Now preparing the top surface to screen-print the component layout.

Here is the set-up to print the board component layout.  Full edge to edge printing makes this a challenging print.

Here are the finished raw PCB prototypes.

Next post we will solder components to the boards and test them.  Here is a peek.

 

Critical Update for build guide step #4!

NeX has brought it to my attention that I overlooked a possible short between +5V and ground.  Here is where the problem is. Back PCB.

The enlarged hole is located where the +5V trace is.  Here.

I needed to remove any chance of short by removing the copper left close to the hole.  I did this by manually moving a counter sink bit with my hand around the hole.  Here is the result.

With the protective Lexan overlays and the trimmed hole, this eliminates the possible short.  Thank you NeX for catching this gross oversight!

Build guide step #5

Many revisions were made to the design of the Arduino PCB before finally we were happy with it.  I would like to say it went quickly, but that would not be true.  I kept adding features to future proof the design as much as I could.  For instance I added several expansion port headers to allow easy access to the expansion port.  And it is a good thing I did, because we will use that expansion capability to add on an awesome feature that NeX has built.  If you ever want any inspiration working with Gameboys just check out his site!  He has a very cool new feature he has built and I would like to thank him for inviting me to test it out! More on that soon!

Once the layout was finalized it is on to fabrication.  Here we are drilling .040 holes and .125 mounting holes into single sided pre-sensitized PCB from MG Chemicals using the CNC router.  I did this in low light as I did not want to expose the edges of the PCB with the overhead fluorescent bulbs.

Once drilled we could align the film to the holes and expose it using a vacuum glass table and a high intensity metal halide exposure unit. Takes 60 seconds or 100 units if you are using an integrator.

Once exposed we then washed the exposed resist away with chemical developer.  Now the board is ready to be etched.

Join us next post as we etch the board and screen print the component layout.  Here is a sneak peak.