HI all, I would appreciate feedback on an idea I am working on. I have some specific power supply questions as well. I'm a software engineer by trade so I know code, but electrical is new to me.
My project is a wearable rocket pack for my kids.
It will have pot joysticks that will play sounds and flash leds when used. There will be multiple switches to cause logic to run turning lights on or off, or a buzzer to buzz, a 10 segment bar led to countdown. There will also be some 5v flashlights that a switch can turn on.
I'm looking at about 2 10 segment bar leds, 10 switches, 8 pots, 4 flashlights, and some speakers.
Leds are in a single group of 16, and 2 groups of 4.
I will be using a mega as the base, with a wav trigger from sparkfun for the sounds. I know about max mA per pin and max for the board. There will be at most 12 leds on at a time from the board, excluding the bar leds which I plan to power via 2222 transistors and either MAX7219s or shift registers. The 4 flashlights I plan to power via 2 RFP30N06LE mosfets (overkill I know), turned on via switches triggering some code.
Everything will be mounted in a chestbox and backpack, made from abs and extruded Styrofoam, covered in tyvek.
Any comments/advice on the overall setup would be appreciated.
My main questions are regarding the power supply.
My current plan is to use a single USB power bank, approx 22000mAh, with a usb plug going to a circuit board, with multiple connections going out. One to the barrel jack on the mega, and one line to each transistor and the wav trigger.
Can I split a single USB power bank this way into multiple destinations without trouble? Do I need to use 2 USB power banks, one for the mega and one for everything else? Do I ground them all together (power banks and mega sharing the same ground)? Is my approach the correct one for powering this monstrosity?
Thank you in advance for your advice