DIY Arduboy V2

Hi everyone. I think my ArduBreadBoy was a success. However, I still feel like some things are missing - important things - and I hope to include them with the next iteration of the ArduBreadBoy. This time I want to make it on some perfboard while trying to maintain the same size. Roughly about 7cm by 9 cm. I want to include a volume wheel this time, a power switch and a power system. I have some LiPo batterys (3.7 V) but I don’t know what board to get. The Adafruit micro lipo seems good but should I get the one with the usb port or not? Because…I don’t want to buy another house :laughing:. I’m still new to power switchs and volume wheels so how would I wire all of that up?
Thanks -Dillyn

I also saw some that have multiple layers of perfboard to fir more stuff so if I could pull off something like that it could be really convenient.

So does anyone know how to wire up the volume wheel and power switch? And micro lipo with usb (adafruit) to the board?

Would a 1200 mah battery be overkill?

A real Arduboy will draw around 20mA to 50mA from its nominal 3.6V LiPo battery, depending on the number of pixels lit on the display and whether the RGB LED or speaker is in use. Assuming your circuit has a similar draw and your 1200mAh battery is 3.7V, at worst case 50mA it would provide power for 24 hours from a full charge.

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How long would a 900 mah battery last for games that have tons of code like Ardynia and Catacombs of the damned? With features like the led and speaker. How do I find the right Li-Po charger and find the voltage of the whole DIY Arduboy?

Tons of code doesn’t affect battery life. As I said, it’s the number of pixels lit on the display (black objects on a white background will draw a lot more than white objects on a black background), plus whether RGB LED is being used (how bright and how often), plus whether the speaker is being used (how often).

To determine the approximate run time, divide the mAh rating of the battery by the current draw. For example, let’s assume the game draws an average of 35mA. With a 900mAh battery you would get 900mAh/35mA = 25.71 hours.

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Oh that’s actually pretty good. So I guess I’ll use a 900 mah battery. But how do I find the voltage of the DIY Arduboy because then I need to get the right Li-Po charger. Because I don’t want it to explode…

You need a charger suitable for the battery you’re using. Then you need to provide the proper voltage to your circuit from that battery.

The Adafruit charger that I think you were referring to earlier (as well as many others) would be suitable for a 900mAh 3.7V LiPo cell. You would probably want to adjust it for the 500mA output.

As for the circuitry, When you’re running from USB, the Pro Micro is running at it’s rated 5V. If you power it from a different source, it requires 5V on its Vcc input or 5.5V to 12V on its RAW input.

However, the LiPo batter only provides a maximum of 4.2V when fully charged. Therefore, in theory you would need a voltage boosting circuit to convert the battery voltage up to 5V or higher. In practice, though, the Pro Micro and the rest of the circuitry will very likely run fine on the 3.2V to 4.2V that the battery provides, when you wire it to the Pro Micro Vcc input.

There is a charger that also converts the voltage to 5v or is he micro lipo fine? If it is, how do I wire it up to the pro micro (the micro lipo)?

I just said the Adafruit charger would be fine.

Wire the GND pin of the charger to the GND of your circuit. Connect the BAT pin to a switch. Connect the other side of the switch to Vcc of the Pro Micro and Vcc (or however the power pin is labelled) of your display.

NOTE: If you wire it this way, never turn the switch on when you’re powering the Pro Micro from its USB connector. This could damage the battery, possibly causing it to explode.

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So when I’m uploading new games or something I shouldn’t turn it on? Whew thats a relief because it’s much cheaper than the one with the voltage boost.

I’ve been reading up and I assume I connect it to the middle pin? If so, then is the right or left ground/vcc or other things. Basically how do I connect a switch to it? This is the switch I’m referring to. Breadboard-friendly SPDT Slide Switch

Correct. When you’re uploading games, you’re powering the circuit from the Pro Micro’s USB port. You want to make sure the battery is disconnected by leaving the switch off.

Connect either outside pin to the charger BAT pin. Connect the middle pin to circuit Vcc. Leave the other outside pin disconnected.

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So any of the outside pins to bat, and the middle to vcc. Okay thanks.

Would I still use the micro-lipo if I want to use a 1200 mah battery?

Hi Dillyn,
I love your energy for hacking on hardware. May I suggest taking a little time to research some of these topics online with Google, as perhaps you’re undertaking a fairly ambitious project. There’s so many great resources- in addition to this forum! :slight_smile:

Especially if you are looking at products from Adafruit~

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I only have a 600 mah so will the micro lipo work with that?

Would 22-gauge silicone wire be suitable because I need to make in a small area but I won’t use really thin wire.

Did you even look at the reference @acedent sent you? It answers this question and probably many more you had about charging.

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