I noticed that when I turned off the power supply (connected to 9V battery), it still showed a green light. This was coming from the arduino, yet I only had pins 5,4,3,GND , A0 connected on the arduino. So where is this unwanted power supply coming from? Would my DC motor also be drawing current f…

Do you think a block or schematic of how everything is connected might help us understand your problem ?

A sneak path through the data lines. Very, very bad for the continued health of your Arduino. That's all I can surmise in the absence of a very much required schematic.

hI, @randomarduino13122 [image] randomarduino13122: yet I only had pins 5,4,3,2,GND connected on the arduino. What were they connected to? Does the other bit of hardware have it own power supply? [image] van_der_decken: A sneak path through the data lines. Very, very bad for the contin…

[image] randomarduino13122: the most common way of connecting: Here on the forum that is usually the wrong way.

[image] randomarduino13122: I only had pins 5,4,3,2,GND connected on the arduino. Your schematic shows nothing connected to the Arduino GND or Pin 2. There are many other oddities in your schematic. [image] randomarduino13122: Schematic of my circuit or almost my circuit. How about p…

I made a mistake by saying pin 2 of the Arduino was connected to something so forget that bit. I did this some time ago so the circuit has been disconnected. But this (see the post) is my intended circuit, I posted the corrected circuit

[image] randomarduino13122: posted the corrected circuit The logic (5volt) supply of the L293 (pin16) is not connected. What is the SW200D part inline with A0 supposed to do. Hopefully you're not using a smoke alarm battery. Leo..

"SW200D" is supposed to be a tilt sensor, i dont really know what SW200D is as for pin16, im only using 1 motor, so why do i need to connect a pin on the other side of the L293D?

Pin 16 is the power supply of the L293D, it must be connected to 5volt of the Arduino. Pin8 is motor supply. Leo..

Unwanted power from Arduino

Projects General Guidance

TomGeorge April 13, 2025, 10:43pm 7

Can you please post a copy of your circuit, a picture of a hand drawn circuit in jpg, png?
Hand drawn and photographed is perfectly acceptable.
Please include ALL hardware, power supplies, component names and pin labels.

Thanks.. Tom....

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Unwanted power from Arduino

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