connecting two devices to the same 5V power pin
March 23, 2023, 09:22
I'm unsing the raspberry pi 4 model B for a project and we need to power two 5V servos, 1 ultra sonic sensor, 1 soil moisture sensor and also a control device for a stepper motor. the pi has two 5V and two 3,3V pins but we need 1 more. Thats why I wanted to ask if it's possible to power something from the above with the same pin?
you should never power high-load devices through pi.
for example servo
let alone several.
oh I've got that out of a totorial so I thought it might be ok
what would be high load?
as long as it provides necessary voltage for them and you connect grounds and you make sure no parasitic voltage feeds through pwm input from servo to pi
then of course 🙂
like this:
servos need stabilised voltage of 5V iirc.
also 6V for that driver is not sufficient.
and you definitely cannot use simple resistor.
What?
Do you use a laptop to power your fridge?
Well, how do you power that pi?
via usb c from my laptop
Say whatnow?
Pi that needs >1A powered from laptop that delivers <500mA?
yeah at the moment, we are doing this so we can work with it: https://howchoo.com/pi/raspberry-pi-gadget-mode
work with it?
the what ?
open its directory in a terminal on the laptop and write and start python scripts
that's what SSH is for
yeah we don't have wifi where we are working
yes you do
your laptop does have wifi
so does pi
so does your phone
well it's our university wifi where you have to log in with your student account every time
and then we found that totorial and gave it a try
so? why do you care about other's wifi networks?
it's like owning a car and complaining you have to steal keys from neighbor to use his car
or rather than "steal keys" i should've used "sign a waiver"
yeah we didn't really look into it, after it worked via usb we were just happy that it works but we wanted to try connecting via wifi anyway it the next days
and connect the pi to a bench power supply
well
since you have bench psu
why don't you power all of it off of it?
🤔
you only need higher voltage for stepper motor
yeah taht would be a good idea
it would, wouldn't it...
or any proper 5V PSU with enough amps
and by proper i mean stabilised.
voltage must not deviate based on power
or just get a DC-DC converter with 5V output
that contains BMS as well so it cuts off when battery voltage gets too low (based on battery specs)
aka step down with battery protection
commonly found in many powerbanks
would it be easier?
of course.
or second output of bench psu
alright then, I'll try that, ty for your help