Hi!
So I made a PCB to control and drive a 4 Wheeled Omni-driving Robot... basically a Roomba.
Thing is. The idea was to power the entire project from a really powerful 7.4v 2S LiPo with a max load of 210 Amps...
Thats overkill, I know. However thats not really my problem, the real problem is that I wanted it all to stick to the PCB, so I have the power of the LiPo go to the VIN Port cuse I thought it was just that. VCC In. In parrelel, the Power also goes to the Motor Drivers.
When I wanted to just test that everything worked and plugged the project into the PC without the Battery, since the test didn't require the wheels to spin yet. The wheels suddenly spun. I went crazy trying to figure what was wrong ( Aside from the Pins of the Receiver needing to be properly defined as the Wheels shouldn't spin in Neutral... ) I found that there was a connection between the Power line that the Motors use from the Motor Driver... which is connected to the Lipo... is connected to the VIN Pin. Duhh, its in Paralel. But what I didn't know was that the VIN Pin is also a VOUT Pin... which... can cause problems when I'm running 4 wheels, plus I'm worried about what happens when the battery is later plugged in.
Needless to say, I'm not an electronics person. I do this as a hobby and have fun goofing around making silly robots that suck away all my spare change~ So I honestly am kind of scared. What will the VIN Port do when the Battery is plugged in? Will it behave like a Power Input, and just receive Power from the Battery? Or will it eventually, or potentially, switch to being an Output, and start feeding back into the Battery or something? I know it really shouldn't happen, but... I really don't want that thing to catch fire mid drive ( At least not before I run it into a wall ).
Had I known about how the VIN Port worked, I'd have planned in a Diode ahead of time... now I kinda need to Drill into the PCB and destroy the Traces to hopefully fix it into one Direction.
But this leads me to a new Problem. Figuring out which Diode to use.
I figured that it probably isn't that unusual for you guys to Power your Arduino Project... though I know that a lot of people just power it via USB or the japanese plug. But, does anybody know what Diode would do the Job? 7.4v going through it... I got a couple but their AWG is really thin and given that the Mega's Data barely shows any Amp Draw, I can't really figure out which AWG or Diode to use for this.
How many Amps will the Mega constantly draw? I realize it varies depending on the amount of pins used and such, but surely there must be a base amount of Amps it draw and a rough average, right?
I know I should probably just get a Wattmeter for this and plug it in line before the LiPo to check this properly, but due to current events, Postage is crazy slow and I'm really not feeling the wait of 30 days for something that could be potentially fixed like... tomorrow.
So if anybody knows something about this, please share it with me.
I thank you for your time and stay safe! 