Hello, just signed up! new arduboy on its way (I just recently got the maker bug, and I might recognize some familiar names here from the pokitto community).
Aside from willing to play the amazing games made for the arduboy, I’m also itching to try building my very first pcb, could someone help me out?
Disclaimer, I have no pcb design skills, this might take a while and a lot of questions.
My goal is to make a dual layer pcb arduboy compatible handheld with the following specs:
uses AA batteries, no idea how many will be needed?
same arduboy components: chip, display, etc.
has flash storage capability
minimize use of micro components and favor big resistors, diodes or whatever else is needed. Unfortunately I will still have to deal with the tiny processor, which seems pretty annoying to solder by hand.
micro-usb or usb-c, whatever requires less hustle
I guess my first two questions are:
what’s the exact parts list?
where can I find the arduboy circuit schematic to make my own pcb?
P.s. yes, I know it’s a long road to learn all this stuff. No, I don’t want to start by getting a bunch of ready-made components.
Sorry for the long post! hope someone can get me the ropes to start : )
I retitled this and moved it over into the help and information section since it sounds like you will need a lot of it before you can start building. My suggestion is to start the thread in the home made section once you have some of these concepts figured out and have started assembling the parts.
You can do it, it’s not that hard, just takes a lot of patience!
If you’re going to run at 4.5V and use a “raw” display with just the chip in the flex cable (i.e. not a module with a circuit board), that voltage is well over the specified 4.0V absolute maximum. In this case, I’d suggest using a 3.3V regulator for the entire system. Regulating to 3.3V would also benefit a flash chip.
Thank you for the advice guys, from what I’ve seen today getting lost in KiKad, the battery aspect will be something I’ll be able to understand once I have a better understanding of the whole thing.
I didn’t even know the flash memory would impact on consumption!
Today I started watching some KiKad videos, it’s starting to make sense, although when I look at the arduboy schematic some symbols are still a mystery, like the P$1 and such.
thank you! this is all starting to make some sort of sense, adding the atmega32u4 to kicad as a first step : )
My steps will be as follow, please let me know if this is the way to go:
design schematic in kicad
generate and order component list
test it all out on a perf or bread board (btw, how do I turn the cpu into something I can stick on a perf or bread board?)
pcb design time!
One thing I did not mention yet, is the reason I’m going all custom with this.
I don’t actually intend on recreating a direct clone of the arduboy, instead I want to mash the arduboy with a Pocket Operator by having the same arduboy components with a totally different button layout made of a matrix + a potentiometer.
Along the way I will decide on the details, such as buttons and screen.
One idea could be to have actual mechanical keyboard switches, in which case a bigger screen like the one used on the ardubigboy might make sense, or the gorgeous liquid crystal display I saw posted here as well.
Dunno, all too exciting and I’m miles away from actually having anything working
Hello, I kinda got stuck now that I need to face the batteries issue.
I’m learning about voltage boost regulators, apparently I can get stable 3.3V out of two AA batteries, which would be my idea goal, but is 3.3v enough?
Apparently this regulator might do, but that’s a lot of components, will I really need all of that? even the inductor (which I barely know what it is)?
“The MCP1256, MCP1257, MCP1258 and MCP1259
are inductorless, positive regulated charge pump
DC/DC converters. The devices generate a regulated
3.3V output voltage from a 1.8V to 3.6V input. The
devices are specifically designed for applications
operating from 2-cell alkaline, Ni-Cd, or Ni-MH
batteries or by one primary lithium MnO2 (or similar)
coin cell battery.”
Only outputs 100mA though, so may not be enough - are you planning on including all the LEDs?
Actually it’s not. If you want less parts you should use more batteries so you don’t need to boost the voltage. (that’s why I sugested 3 earlier)
Think of it as a transformer.
Note if your going for the big 2.4" OLED display you’ll need a DC-DC converter for the for the OLED panel. It requires a higher voltage (somewhere 12-14V iirc) lower is possible at the cost of less brightness.
You could leave out the DC-DC converter for that too if you add even more bateries
If you’re going to add mechanical keys and the 2.4" display it will get relatively large and adding more batteries shouldn’t be a problem. It would become heavier ofcourse but it would also last longer.
It’s better to regulate, but with 3 or more batteries you should be fine to boot and run for a while. But you will only get maybe 50% of the battery life you would with a charge pump, because the batteries will still produce a ton of current below the voltage cutoff of the mcu.
That said, with primary cell AA or AAA batteries you are probably talking about dozens of hours of playtime anyways so it may not matter that much.