NodeMCU not detected.

You have installed the driver for the NODEMCU specific USBUART chip on it ?

You have the correct com port selected in Arduino IDE ?

COM port found in windows device manager. COM11 in this case, see attached.


Regards, Dana.

Hi,

some nodeMCU need a capacitor at EN pin to GND (1uF?)
or a button (don´t know which one) to be pressed before/during upload.

Klaus

I don't think this is a problem of using the ESP bootloader. The ESP8266 or ESP32 on the nodeMCU does not have a USB port, it uses a CH340 or CP2102/2014 as an external interface to one of its serial ports. If the USB interface isn't working the problem is communication with the host computer.

If you are powering the board through the USB connector, measure the voltage between GND and 3V3 pins. The 3V3 should have 3.3V on it and it is fairly critical. If it is outside the range of 3.1V to 3.4V you will have problems. The USB handshaking lines normally connect to the reset and GPIO0 pins to put the ESP into loading mode.

Did the problem start after an OS 'update' ?

Brian.

NODEMCU pin has a pullup on its module to 3.3V. No need for a C.


If using Arduino IDE to program generally do not need to press the flash button on
the module. Just compile/upload usually suffices.


Regards, Dana.

The flash button generally associated with :





Regards, Dana.

Hi,

I definitely have some ESP32 boards around that suffer from the "not going into programming mode" problem.
They have the CP2102 chip installed and they have a resistor on EN installed. They suffer from a timing problem.
RESET is taken away the same time when the FLASH signal is taken away, this causes a timing problem on these so called "strapping pins": They change state at exactly the same time when their state is being latched in. So it´s not sure which level they detect.
A capacitor delays the EN signal, so that the latched state becomes reliable.

The modules I have did not enter programming mode reliably. After installation of the said capacitor they enter programming mode 100% reliably.

Afaik most ESP32 modules don´t suffer from this timing problem. (sadly mine do)
To find out whether your boards are problematic, just do an internet search using the exact brand, board type and revision.

Klaus

Interesting we have gotten such different results. Although my comments apply
to ESP8266 NODEMCU V1.0 and later.

Regards, Dana.

The NoDEmcu is not recognised by windows and Device manager reports it as "USB Single Serial". The chip on board is CP2102 but any driver does not resolve the problem. As the nodemcu is not detected no further progress of uploading the sketch.

And it does not report a COMxx port # ?

Sounds likes its firmware needs flashing :




Regards, Dana.

yes It s not reporting COMxx port.
I will try Flashing firmware. Thanks every body

yes It s not reporting COMxx port.

Click to expand...

The Arduino IDE provide an option to log the output programming result into console ( 'verbose' on Preferences tab ).
By sharing what is there you'll surelly get a more accurate help here.

Hello,

Firstly, ensure that the USB cable connecting the new NodeMCU is functional and capable of data transfer. Additionally, verify that the new NodeMCU is properly seated in the USB port. If these basic checks yield no solution, it is possible that the new NodeMCU might have a firmware issue or a faulty USB port.

Attempting to re-flash the firmware or trying a different USB port on the computer might help resolve the problem. Additionally, checking for any driver updates or reinstalling the NodeMCU drivers could also be beneficial.

Troubleshooting step by step through these considerations may help identify and address the root cause of the detection issue.

Hope this is useful!