ESP8266 Community Forum

- Mon Jul 25, 2016 5:13 am #51470 Hey guys.

I burnt a code into the NodeMcu 12e using the arduino ide. It runs perfectly. And also it is getting the power from the USB cable connected between the NodeMcu module and laptop.

Now, I want to power up the NodeMcu module externally. Not using the USB cable. I tried connecting the arduino 5V output supply to the NodeMcu. With the ground also obviously!

But the module just doesn't run the code. I tried resetting once i change the power supply also. But still no positive output.

What could be the problem?

- Mon Jul 25, 2016 9:02 am #51479 Hi,

the 5V pin of your Arduino board might not be able to provide enough current for your ESP, depending on what else is being run on the Arduino (iirc the maximum available is ~400mA when the Arduino is powered by USB).

Apart from that, what is the sketch supposed to do and how do you know that it isn't running?

- Mon Jul 25, 2016 9:45 pm #51506 I built a little wifi locator using an ESP18266 12, hooked it up using a small battery left over from a broken mp3 player. I put in a small charger board, and hooked the battery to the vin and grnd pins on the ESP, it has been working great now for well over a year, for a display I am using one of those small oled displays and have the whole deal mounted in a small black project box. It is very handy when we are traveling, as I have a travel router in in our motor home, so I can easily check with my little device to see what wireless is available and if it is protected or not, then hook into my router and give it access to free wifi and we are set to go where ever we park our unit for the night/week/month depending on how long we wish to stay. The battery is a 3.7 volt lithium flat pack, and thus far has only needed the initial charge, as the thing is only used for a few minutes every once in a while, and I did put an inline switch so it takes no power till I give it the go.

- Tue Jul 26, 2016 11:27 pm #51566

Hi,

the 5V pin of your Arduino board might not be able to provide enough current for your ESP, depending on what else is being run on the Arduino (iirc the maximum available is ~400mA when the Arduino is powered by USB).

Apart from that, what is the sketch supposed to do and how do you know that it isn't running?

I am making a home automation prototype.

I have made a binary table, with each binary combination performing a different end operation, such as lighting, device operation, etc.
The binary code, currently I am giving to the NodeMcu through the Serial Monitor. I just need to replace the Serial Monitor with a touch screen.

So as soon as i hook it up with the Arduino, and i give the command through an Android app (Supports the same binary code and commands), the NodeMcu doesn't work. No end device operation performed.