Detect voltage drop across the wires which power up ESP32 device

Hey, I am new to this kind,Actually, I have been trying to check the low DC voltage drop across the long wires. As I have been trying to give external power to ESP32 device which gives secondary power backup using the wired connection. Before starting physically with higher voltages. I am looking for any simulation software which helps me in testing the voltage drop across the wires Need suggestions what American gauge based wires I should use to travel the 12v DC voltage at 30 to 40m.Leads on this will be much appreciated.

Hi Nate-The tricky part about this is that the current required by the ESP32 is not necessarily constant. Let's say you determine that you will have 1 volt of drop in the wires while the ESP32 is operating at full load. This means you will have to feed 6 volts into the long wires to have 5 volts at the ESP32. Now when the ESP32 stops drawing maximum current, the voltage will rise, which may damage it. Let me suggest that you take a slightly different approach. Start with a higher voltage, maybe 12 volts. Feed this into one end of the wires, and at the far end, where the ESP32 is located, use a switching regulator to step the voltage down to 5 volts.  Here's a regulator that will do the job nicely: OKI-78SR  .  It can deliver up to 1.5 amps at 5 volts, and is very affordable. Now the voltage drop in the wires is much less critical.It still wouldn't hurt to know what the voltage drop will be.  To determine that, measure the current into the ESP32.  Determine the resistance of the wires by using a  Chart of AWG wire sizes. Now use Ohms law, or an Ohms Law Calculator to determine the voltage drop of the wire. If you start with 12 volts, you need 5 volts, and the regulator requires at least 7 volts, you can afford to lose  almost 5 volts in the wires before you get into trouble.-Rick

Nate,The chart on this site may help give you an idea of voltage loss on wires. It's mostly useful for a 12V system where you are using more than 1A so it may not apply to your application.http://www.affordable-solar.com/wholesale/solar-tools/wire-sizing-charts/For a more accurate calculation, Wikipedia has a nice table of resistance for different wire gauges.https://en.wikipedia.org/wiki/American_wire_gaugeOnce you know the resistance of the wire, you can easily calculate the voltage drop when you know the current.