BigBoy Advance - Bacteria's GBA portable with 8" screen

[bacteria]

Spent over an hour on this, making a logo for the system; which i'll use for the front plate and also back of the system too:



Like it?

Letter background would have been nice as black, as per original font style, however of course would not have shown on a black background.

Can't print the logo for a couple of days as waiting for new printer inks.

Super Mario font, of course, tweaked though a bit.

[bacteria]

Here is the case with the Select button in place and the screen cover protector in place (minus graphics).



Hadn't tested the screen for a while, works fine. This is a PAL game working on the RetroDuo (NTSC output); shows it works fine anyway. Need to mod the RetroDuo board a bit now I know all's well.

[bacteria]

Hard wired the AD Adaptor to the board after removing the game port, removed switch and wired that. Tried to solder the 7805 to the board but gave interference so moved it.

Anyway, working fine so far.



Need to probably relocate a couple of capacitors now, then test audio (not connected audio up to the system yet), then assuming all fine, can start to assemble the GBA and RetroDuo into the system case, test again, then start work on the controller, batteries, etc.

Akira from my forum has made me a far better logo for the system, will use that.

[bacteria]

Using a different regulator for the 5v, as the 7805 would need a heatsink, not a large one of course as the regulator doesn't get that hot, so used one of those cheap Chinese regulators, works fine. Installed the AD Adaptor into the case back with 3 screws, next jobs will be to install the motherboard for the RetroDuo into the case back; then work on the controller which will install to the case front. I'll then know the space left for batteries and if viable.

[CRTGAMER]

Really looking good. What is that coating, was it from the concrete mold?

All the work you are putting into this, how hard to include a video output for the big screen? I imagine there would have to some sort of conversion of the video ratio. Even though there is already the GBA Player with the Gamecube, would be cool if this was part of your mod.

[bacteria]

Can easily make a TV out port; the output is normal composite although outputs NTSC modern PAL televisions are fine with NTSC.

Yes, a lot of work goes into making portables however it is an excellent hobby.

I'm going to use the same casing from my mold for a TurboGrafx and also N64 as separate portables.

Toying with the idea to include a plug'n'play or two into this GBA project as the screen is composite anyway.

[bacteria]

Made good progress, wired up the controller and all connections apart from shoulder buttons, then can check 4 x Li-ion cells will fit up ok, connect up battery power, switch, etc.



The wires between both systems are not shielded cables as they use the ground for that, which is connected between both parts in the cables. As the cables are unshielded with metal strips, i've made the cable more flexible in sections so can bend easily as the case is closed.

[bacteria]

Opened up the charger for the Sony compatible NP-F550/F570 Li-ion cells i'm using.





Too large, reduced the board by removing the mains input sections and just kept the DC line section. Actually reduced the board by another 1/4 after this too; with some more relocations and rewiring.



Basically, 7.5v input to the system; goes to a step-up regulator to output 12v, then feeds the charger unit, and then the batteries; two sets of cells in parallel. When system is running on mains it will charge the batteries at the same time, although the cells will not be running the system; if the system is running off batteries then the mains connection will not be present.

[bacteria]

Today so far i've installed the shoulder buttons, installed a 3PST switch, decided to wire up as illustrated before however have middle position for off and also charge batteries if portable is not connected to the system (in which case system off but batteries charge); otherwise the only way to have the system charging the batteries is if the system is working; so made sense to use a 3 way switch (single pole). Also installed two discreet tacts for volume control; screen is at the right level as best as can make it so no point adjusting that later.

System seem to work fine, however need to do various proper tests. Also makes sense to relocate the LED for the red and green illumination to show the status of charging the batteries.

Once the system is initially tested, I want to run the system until the point the batteries drain to the point the screen or console stops working; liable to be the screen first though as the RetroDuo runs off 5v via a regulator so will work while the batteries are over 7v, and I image the screen will die before that level.

I'm not fussed how long the system will run before this happens as long as it's over 1.5 hours, as that's a reasonable time for a portable; longer is of course better. I have 4.2amps in the system and I know it runs happily off a PSone PSU which is 7.5v at 2amps, so I should get over 2 hours with any luck. On the subject of the batteries, they were pretty drained when I started to charge them, the LED went green to state cells charged after 6.5 hours approximately; the input for the charging is 150mA at 12v and outputs 600mA; so I guess the step-up regulator, which is supplying the charger unit 12v from 7.5v is probably using about 300mA (?), so hopefully the PSone PSU has enough to run the charger and system at the same time, or i'll have to use a different PSU.

Going to relocate the charger's LED, and when know what happens when the voltage gets too low will determine what I do about installing a low voltage indicator or not. What I mean, is if the screen wobbles like the PSone screen does a few minutes before the screen switches off, then you don't need a low voltage indicator as no point; however if the screen just goes off without warning then makes sense to put in a low voltage circuit. In other words, have various testing to do yet.

I also want to do the graphics for the system too.

So, as tempting as it is to close this system up, not going to until done the testings.

Here however is a pic of the "finished" system:



As close as one can reasonably get to closing a pair of case halves perfectly, it isn't easy to do that properly as there is usually a fraction of a millimeter gap at some parts of the join. When I close the system up, I have an idea how to make this seamless...

[bacteria]

Relocated the LED to show red/green light for charging.

In process of doing stress test on system to see how long the batteries last for before drain too much to power the system.

Already found two errors in my wiring, "A" and "B" are wired wrong way around, and the volume up button is doing something else so using wrong pin; will rectify that later after battery test.

When I know when the system goes off I can also check what voltage that is, can then set up a step-down regulator to that voltage, plus a small extra, and then see about a low voltage level LED if needed.

Separating the two halves by a piece of card at moment as not insulated the electronics in the two halves by electrical tape yet, and don't want any shorts.



Been going for 15 minutes so far, expecting around 2 hours or so, so will keep a tab on the unit closely after an hour and a quarter and then every few minutes afterwards. Might last longer than two hours, no idea at this stage.

Updates later!