Hopefully a simple question... I'm just starting to dabble with an Arduino uno and a esp32, stepper motors, joystick controls, servos, etc., with my robotic obsessed 8 year old and I need an external power supply.
So we've been playing around with a few things (made a robotic arm with servos controlled by joysticks) but it seems I need to power my breadboard with an external power supply. I heard powering everything from the Arduino is bad and powering anything on the esp32 doesn't work. So... how do I do this? I've read a lot but don't want to fry me or my electronics. I've seen the breadboard power supply controllers, old USB phone chargers wired into a breadboard, etc. etc. I have an uno with USB and the power jack for wall wart. Can I just use both of those together and then power my external items from the uno? I'm guessing that is bad.
Any easy ways to power my simple projects? For both the uno and hiletgo esp32? I would love a system that I could power either via wall wart or battery if possible? And how do I wire it in? And how do I make sure I have enough power but not too much? Have you got the idea that I am really new at electronics yet? Bonus question, any websites that have absolute beginner info on this stuff? I am just trying to encourage my son's hobby.
There is no such thing as too much. No matter how much power you lean against it, it will only take what it needs.
[quote="spiffy577, post:1, topic:879210"]
I'm guessing that is bad.
[/quote]
Dead right, it is. Arduino, ESPdahdedah is a controller, not a supplier. Heavier devices like servo etc. must be supplied by other sources. These devices need to be properly catered for and, by comparison, Arduino goes along for the ride.
Well, for starters the Arduino actually operates on 5 V, so a regulated 5 V supply is the basic requirement. A USB "phone charger" is arguably the most readily available source of regulated 5 V, about $10 (Australian) in the shops but often found second-hand in "thrift" shops. Best stick to genuine brands.
The ESP includes a regulator to drop 5 V to its actual working voltage of 3.3 V, that is practical as 3.3 V supplies are not a common retail item. So the same power supply suits.
The regulator on-board the UNO is mostly useless. It does not have a proper heatsink so while it can power the UNO alone if you supply say, 9 V, connecting devices which draw more than a couple of hundred milliamps to the 5 V pin is likely to get you into trouble.
If you feed 5 V into the USB connector, you can draw 500 mA less the current the microcontroller and USB interface chip draw, something like 50 mA, from the "5V" pin plus the output pins in total. The polyswitch is supposed to shut down the USB supply if the current draw substantially exceeds 500 mA.
If you power various devices directly from your 5 V supply, however much current it all draws you can use that to supply the UNO as well via the "5V" pin (and ground of course) but you do have to disconnect the "5V" pin (but not ground) when you plug it into a PC via USB.
An used computer power supply will give you 3.3v, 5v, and 12v clean regulated power. Simplest and most inexpensive dedicated power supply you can find.
