I plan my weather station and have some basic questions.
I use a Wemos D1.
It can output 5v and 3.3v.
I'll use only the 3.3v becaus for 5V inputs i need to use a level shifter.
Is it correct that the number of devices, which i connect with G (GND) is NOT limited? I'm not sure, if i see all important facts, because i'm a newbie.
I think i'm only limited by the devices, i'll connect with 3.3v output. The devices are not allowed to use more than 500mA alltogehter.
Is that right?
Is it allowed, that i post my wire diagram here?
Thank you a lot!
GND is not a problem.
You power your board from USB, right? This means the input voltage is 5v, and the connected devices works at 3v3. In this case, a voltage converter is used on the board, which, at a current of 500 mA, is likely to overheat.
Regarding connecting devices to GND, there is technically no limit to the number of devices that can be connected to GND. However, it's important to consider the total current that will flow through the ground connections. If too many devices are connected to ground, the total current may exceed the capacity of the power supply or cause ground loops, which can introduce noise into your measurements.
My other device is connected to my analog pin, so it not use the 3.3v output pin. the device produce some mV and the anlog pin meassure this.
So it doesn't matter the max. 500mA right, cause it don't use the voltage converter?
the sensor produce power and the wemos measure this voltage
The other two sensors consume power, but not more than 10mA so it should work
my wemos d1 is in my garage. the senosr is on the roof. so i need more than 3 meter cable from the arduino to the roof.
wahts the chapiest cable you wold prefer for this solution? the jumper calbe is not the best way, or?