Worklog The Wii SPii

[StonedEdge]

Enter the Wii SPii, my 2020 summer contest entry:

The portable will be modeled after an original SP console and feature a full OMEGA trim with NAND relocation and AVE relocation performed by me, as well as an all-in one PCB showing off all of the latest boards designed by the awesome members of the community (depending on timing of the release of the direct drive board)

I have made some decent progress on the main PCB as well as the case. Looking forward to finally completing an entry this year and seeing everyone else do the same!

 

[wudopecker]

i hope you can get your own omega trim working, looks really difficult

 

[printsmith3d]

Looking good! What's your solution going to be for a Z button?

 

[スープ]

WOW! That's a crazy concept! Cant wait to see the build process and eventually the final product!

 

[StonedEdge]

I spent most of these past two weekends ( thanks to robertlong13 for answering my questions around ADCs, how they work in microcontrollers, and many more tips for getting starting with PIC programming) modifying the UAMP source code to allow the thumbwheel potentiometer to set an ADC value to control volume levels. This is acheived by reducing the resolution of the ADC values to match those of the volume output. The ADC can read a 10-bit value between 0 and 1023 (VCC), but we only require the ADRESH register to hold 8-bits (5 for volume, 3 for hysteresis). We implemented the hysteresis function to make sure that volume doesn't randomly bounce between steps when you turn the wheel. I also added a short line to make sure that the volume can only be changed if the pot value is different from the previous value set in software (probably overkill here but I did it anyways by declaring prev_pot_value as 0 and writing this to the amp before the first write loop). I also made some changes to change the RGB LED to always on when the system is powered (light blue) and switch to red on low battery. An orange LED is connected to a GPIO pin that detects when the charger is plugged in to show charging status.

This is pretty much it for the CAD work now. I've integrated most of the stuff that I need (apart from Z-buttons), including conducting test prints to check for overall tolerances. The PCB will cost me around $45 from JLCPCB with a stencil which is pretty neat, as well as the BOM being about 65$, so about $110USD for that in total. Next step is to trim an OMEGA, relocate all the things, and try and get something to boot.

I know I am probably acting pretty early but the quicker I can verify a working trim the quicker I can focus on starting the build!

General overview of the front of the portable. All of the buttons will be resin printed in white, along with white switch analog sticks.

Thumbwheel potentiometer to control volume levels. Spin it clockwise to turn up volume, for volume down, anti-clockwise.

I am using these very low-profile tactile switches for the DPAD, ABXY and dual start buttons (thanks to GC+ 2.0 functionality). They are really low profile. Gman has used these in several of his projects with good success. You can find them here: https://www.digikey.com/product-detail/en/e-switch/TL3315NF100Q/EG4620CT-ND/1870400

Here is the portables vertical stackup. The case will house a 4 layer PCB with everything on it as I mentioned in the above post. The switch stick FFC connectors wouldn't fit on the other side, so I made an indent in the case for them so that the buttons can remain flush with the case. (Ignore the positioning of the pot (and the connectors, woops lol) for now, I need to change that!))

The diffusers will be 3D printed in transparent filament. They probably won't be 100% clear unless I resin printed them, but they should act as a decent "light pipe" to diffuse the light well. The top LED is for charging, the bottom is for power indicator/low battery indicator.

Front View:

Back view:

More to come!

 

[StonedEdge]

Looking good! What's your solution going to be for a Z button?

I haven’t really thought of anything yet, but probably just a regular squishy tact with a button next to the right trigger. There isn’t really much room anywhere else in the case, it’s pretty tight!

 

[Dmcke5]

Looking awesome mate! I could make those light pipes out of a bit of clear plastic pretty easily if you ever wanted them done.
One thing I wish I was better at is PCB design. What software was this done in? I have the basic principles of circuit design down (for simple things, anyway) but I generally end up designing my PCB's manually in Solidworks. Its tedious but I know the software well so I'm at least able to all my parts in the right places and design the PCB in a way that it fits. I tried eagle and found it frustrating, I could never work out how to get it to shape the PCB or precisely position components (like buttons etc) on the PCB.

 

[StonedEdge]

I painted the back half of the case this weekend. I used pure metallic red from Tamiya from Amazon for the finish with a semi-gloss clear to make sure that it’s not too shiny. Didn’t get a chance to do the top half of the clam or front base half since I’m moving out Wednesday. Soon!

Before the massacre:

Representation of my hands after sanding for yesteryear. All bloody lol. A tough battle.

Spoiler: After:

Victorious!

 

[switcher]

looks amazing stoneEdge, congrats.

 

[StonedEdge]

Not the most exciting part of the build process, but I have finished painting the three parts to the clamshell. I am really happy with how the paint has turned out - its such a big improvement over the first G-Wii I did - practice definitely makes it easier to do a good paint job. The semi-gloss clear counterbalances the metallic sheen nicely. It is not perfect by any means, but I really hate this part of the process, particularly the sanding required to get a nice smooth finish for the button grooves/conical holes. I hope my hands never have to touch bondo ever again. A pain in the ass would be a huge understatement. Just to give an idea, it took a full weekend of sanding, priming, bondoing and repeating to get this finish... I think the result was worth it though.

The next step is to let the paint dry for over a good week or so to make sure its solid, and then start the build process. My PCBs from JLCPCB should arrive this coming week (if there is no unnecessary holdups due to COVID-19) and the parts from Digikey are also on the way. I have already trimmed an OMEGA but have yet to relocate the AVE or perform any tests on that. That will be the next step. Let me know what you think! I am excited!

EDIT: Added more pictures (full body shots) below:

 

[Dmcke5]

Looks like a really nice finish from here, nice work!

 

[StonedEdge]

Looks like a really nice finish from here, nice work!

Thanks! I recently got the buttons resin printed in black. I said I was going to go with white resin for these and white switch sticks, but I didn’t think you could go wrong with the black/red combo. The faceplate is also anodized in a matching black colour so I think this will look nice

 

[StonedEdge]

Today I received the PCBs from JLCPCB (finally!) after a month. Usually JLC is fast shipping but because of corona, it took a lot longer than I anticipated. If anything, they look good, so if they don’t work, I’ll have that at least. The quality is always fantastic with them and these boards look to be no exception.

I’ll order the parts from Digikey this weekend along with some new solder paste as the old stuff has gone off and hopefully assemble these with no issues. I did notice a couple of issues already, one being that I forgot to include ground plane vias for the LM49450 and PIC IC and one of the regulators. I hope this won’t cause too much issues in terms of heat but we will see. Should be OK.

Fits like a glove! It’ll have USB-C power delivery charging, RVL-PMS for power management, GC+ 2.0 from Aurelio for full GameCube controller functionality and also full digital audio thanks to Gman controllable via a 10k volume wheel pot, all on this tiny little PCB. I ended up going with a 4 layer and definitely glad I did. This board would’ve been a mess with 2 layers.

Looking forward to seeing inevitable failure but hopefully a few jumpers/tricks can get this boy working soon. Here are a couple of pictures of it all coming together. I really love the switch sticks in this portable.

 

[StonedEdge]

I got my parts today from digikey, and soldered the majority of the components on to the prototype rev1 PCB. The BQ battery management chips are out of stock, so that’s really the only missing part for now, as well as a couple of caps I blew away with hot air lol.

I still need to clean this up considerably, including reflowing a number of components with some flux and checking all the joints are all OK. A lot of them are pretty shitty as the solder paste I used was quite old and didn’t reflow as nicely as I’d hoped.

After that, I’ll program the ICs with my pickit3 and test the regulators work as intended. Apart from that the USB-C port and headphone jack line up really nicely. I did have to sand the headphone jack to get it to fit but not by much.

 

[Fruity_Grebbles]

By Reggie is that gorgeous.

 

[StonedEdge]

So some good news and some bad news. I’d say about 40% good, 60% bad.

First, I’m going to need a second board revision because stupid me shorted the power muxer input from the 5v regulator and it’s output pins, resulting in the USB never actually getting 5v and the muxer practically becoming useless. This will be an easy fix in hardware. The second piece of bad news is that I shorted two BQ chips in one sitting and couldn’t get the batteries to charge. Reason being was that chip one had an internal short, chip two I accidentally shorted B+ to GND by probing around with my multimeter to check if the voltage went up at all. I really should invest in a bench PSU to actually measure current draw. Anyways, the result was magic smoke.

The good news is that I managed to negotiate 12V out of my charger and get all of the regulators to work which is a positive for sure. This month and all of June I will spend on doing revisions to the board, including beefing up some of the traces and making sure I have adequate spacing between the pours and traces. Oh, and also moving GND pads away from B+ as much as possible.

A bit disheartening honestly but I’m trying to look at the positive aspects for now. I still have one more shot at a rev 2 board for the contest! Will try my best.

 

[StonedEdge]

My screen finally arrived from China today. It will be interesting as this screen can display 24-bit RGB and is 640x480, so it should look a lot crisper than the 320x240 display used in the Gboy. It was quite expensive and I am yet to test how the colors look, but I do have a trimmed OMGWTF Wii to test it with this weekend.

The screen barely fits in the top housing without major modifications being made to the driver board. I have to replace the larger 27Mhz crystal with a smaller SMD one, as well as most likely replace the backlight driver inductor with a smaller SMD footprint in order to fit the screen and driver board in the tight case. I don't have a good enough multimeter to measure the capacitance of the xtal. The one linked below has a maximum load capacitance of 8pf which I assume might be too low. Would anyone here familiar with the driver board and RTD2660 be able to tell me what type of xtal I would need? Shank has also replaced the xtal and inductor for the backlight driver for the RTD2660 chip, but I just wanted to be sure that these two replacements he gave me below would suffice.

27Mhz Xtal: https://www.mouser.com/ProductDetail/520-ECS-270-8-36CKM
Backlight driver inductor: https://www.mouser.com/ProductDetail/81-LQH2HPZ220MDRL

In other news, I got the replacement BQ battery management chips and the batteries are now charging flawlessly which I am really happy about!
I need to repaint the top half a little bit since it got sun damaged but that shouldn't be too much of an issue. Here are some pictures of the screen barely fitting inside of the top half of the clam. I had to remove the metal cover on the front for it to fit. This will be replaced by a custom anodized front black faceplate in aluminum which I should be getting in the mail within the next two weeks. I originally was just going to print this in PLA but it didn't look as professional in my opinion. PLA also is more flexible than aluminum and since the front faceplate is only 1.5mm, it was better to have it machined. The picture doesn't really do it justice but it came out really shiny and nice.

 

[StonedEdge]

I added an official Nintendo sticker from an SP to give it an authentic “Nintendo” feel. I personally think aesthetically speaking it looks really good!

 

[StonedEdge]

Today I got the little buttons in the mail which have been resin printed on an Elegoo. They look really nice and feel fantastic, a little bit of wet sanding and they will come up even better I hope!!

I am going to be honest, the dpad feels horrifically bad with the clicky dome tacts. I didn't integrate any sort of pivot and it really feels like it needs something like that, otherwise it just feels like I'm pressing ABXY buttons. All of them will need to be raised up slightly with some little spacers on each side. I forgot to integrate these into the resin models, so I will have to print something and glue them on the bottom which sucks but oh well!! Idk if you call them that, but right now the dpad is flat and they dont actuate the buttons at all, oops. It's also slightly recessed, so im hoping the spacers will raise it slightly so it'll be nicer At least the ABXY buttons feel really good, so I'm happy with them

 

[MRKane]

Actually some PS2 controllers had a rocker under the dPad that clipped onto the bottom of it, but I'm sure you'll come up with something that works - it's looking super sharp!