ESP8266 Community Forum

I've got a NodeMCU and the have a odd problem where the ESP always seems to be running in AP mode. On my phone if I run Wifi analyser I can see the AP with a SSID of ESP_xxxx and there is no security setup on it.

Even if I upload the standard blink code, the device blinks and ESP_xxxx is visible again.

I've tried wiping the flash with esptool erase_flash. After I upload blink code, or any other code (With or without wifi configured) the flaming ESP is in AP mode.

What gives? Losing my mind on this.

Since the WiFi stack runs in a separate thread, you have to set its mode in code.

In Arduino, you can do this with WiFi.mode(x), where x can be WIFI_AP, WIFI_STA, WIFI_AP_STA or WIFI_OFF, for example:will set the ESP into client ("Station") mode.

When the current firmware is the default AT-firmware, you have to set the mode with the AT+CWMODE command, for instance:will put the ESP into client ("Station") mode.

That did the trick, Thanks very much. I have a few of these devices and this was the only one doing this so must have been enabled at the factory.

The autoconnect behavior is useful, and considered by many to be a feature. But it can be confusing and cause unexpected behavior when you are tinkering with lots of different things, using the same ESP8266.

Here's something I did a while back to get around this, put these in Setup():

// these eliminate the chance of 'already connected' failure in WiFi.begin()
WiFi.persistent(false);
// only needed once, SDK saves it somewhere
if (WiFi.getAutoConnect()) WiFi.setAutoConnect(false);


WiFi.persistent(false) disables WiFI.begin() from saving the mode and credentials. WiFi.setAutoConnect(false) disables the autoconnect (in case there are already some saved WiFi settings.)

Looking at it now, I realize I don’t know what effect it has, if any, on 8266 coming up as AP when not explicitly starting WiFi...