Damn you @davidperrenoud. you make me choose between chocolate and horizontal
Yes, that is a good criticism. It may indeed be more coherent to add 4 through-hole resistors for the RGB LED and speaker and use a Pro Micro or Genuino Micro (although there is really not much place for the later one on the horizontal design). It would not be practical to add a level shifter (2 transistors, 3 diodes and 7 through-hole resistors) but this could be easily corrected with a better designed OLED breakout board, like the one from TinySine.
This device will never be as thin, and thus as “pocketable”, as the Arduboy. Therefore, I wouldn’t think size would be as much of an issue. I’d still be striving for as close to 100% software compatibility as possible. As I’ve said, it adds complexity to make sketches compatible with multiple hardware platforms, so this may not be commonly implemented, especially if your device ends up to have a low overall quantity compared to the real Arduboy. In my opinion, increasing the size slightly to accommodate a Genuino Micro, if necessary, would be a good trade off for increased software compatibility.
You’re going to have to design your board for a specific OLED module, unless you get creative and lay the board out to accept multiple parts. You’ll have to trade off between cost, convenience, real estate, availability, etc., when deciding which OLED to use and where the level shifting is done.
Note that using a level shifting module, instead of discrete components, is still an option. Since the common ones only have 4 lines, you would need an additional diode and resistor for one of the signals (I’d use it for the reset line).
F.Y.I. Since the signals to the display using an SPI interface are unidirectional, you don’t need the resistor on the input side of a BSS138 transistor type level shifter.
Here is my “size” problem (Pro Micro or Genuino Micro on the bottom side):
Also, if I put the buzzer somewhere on the bottom side and remove the non-essential RGB LED, I can put some 0.1" prototyping holes around the screen. This way, if someone wants to add the RGB LED, a multiplayer cable or some other extension, he has some place to do it.
So make the board a bit higher and wider. Move the A and B buttons down and the display up. Place the Genuino Micro just below the display connector and above the lower red button (I don’t know which is A or B), and between the Right D-pad button and the upper red button. Put the prototyping holes in whatever areas are left.
Otherwise, go with the vertical design. It’ll be closer to the Arduboy that way.
And here is the new version !
Does anyone know if the white silkscreen is broken because I put it too close to the bottom of the PCB or if it is because of the fab I used (Ragworm)?
Nice job! Are you cool with sharing the source for the PCB?
Not yet, but it is planned as I did it all in Kicad.
Also, I can send you a PCB, just drop on IRC!
I have found 8 x 8 mm buttons which fit in the same dimensions as a retail Arduboy, similar to my original idea:
I am not sure which design to keep. The horizontal design looks more lively, but the vertical design has a more consistent branding and leaves more place for extension.
And, as I’ve already mentioned, the vertical design also makes it easier to squeeze in an Arduino/Genuino Micro instead of a SparkFun Pro Micro, giving the additional I/O pins that allow close to full production Arduboy compatibility.
I knew it! I was sure you would say that.
And here is the new version, before and after soldering!
I can sell a couple of it for $29 for those who want to help me recover the PCBs and components costs (if @bateske is okay with that).
Of course I’m OK with it! That’s awesome! Even if I wasn’t OK with it how am I supposed to stop you?
Is it wired as a DevKit or the production version?
Is the staggering of the holes intentional? If so, why?
The staggered holes can help to align the pins, and hold it captive while soldering. This might be the result of using a sparkfun library, because I know they are a fan of doing this.
Production version, but the buzzer uses only 1 pin.
Exactly, the staggered holes hold the pin headers in places after you flipped the board and while you solder the pins which makes the job easier for beginners. It is an idea from Sparkfun which I have replicated in Kicad.
Hey man, are you still sending out pcb’s and if so, I would like to get one. How much would it be?
I have just 1 kit left in stock but the screen is green (the pixels are white but the PCB itself is green).
If you are interested, click on my username and send me a message. It’s $29 + shipping.