Cannot initialize ESP-AT Lib

Summary: Getting error “Cannot initialize ESP-AT Lib!” when using Wifi HTTP or HTTPS examples from the Wiki at . An older version of the ESP-AT Library works but the current version on Github doesn’t.


I’ve been using the WIO Terminal with Wifi for some time and it always connects to the network and to the webserver just fine.

But today I installed Arduino on a different computer and downloaded all the libraries I needed from Github. Now when I run the WIFI example I get the error “Cannot initialize ESP-AT Lib”.

If I use a previous release of the ESP-AT Library it works fine. But the current release on Github doesn’t.

I would have posted this in the “issues” section on Github but it looks like it has been disabled.

Hi @Dennis_Mabrey

I just tested with the latest esp-at lib and seems to be working fine on my end

Which verison of esp-at lib you are using, let me recreate this

Hi. I have the same problem using the develop branch of the library. The WiFiScan example works (as you have shown here) but anything that actually connects to a network (e.g. SimpleWiFiServer) fails with the following sort of output in the serial monitor (I haven’t managed to find a version of the esp-at library that works for me):

09:41:41.739 -> Device reset detected!
09:41:45.414 -> Cannot initialize ESP-AT Lib!
09:41:52.539 -> [E][esp_event_loop.c:99] at_unified_cb(): at_unified evt: 4
09:41:52.539 -> 
09:41:53.044 -> Connecting to WiFi..
09:41:53.525 -> Connecting to WiFi..
09:41:54.035 -> Connecting to WiFi..
09:41:54.510 -> Connecting to WiFi..
09:41:55.017 -> Connecting to WiFi..
09:41:55.525 -> Connecting to WiFi..
09:41:56.027 -> Connecting to WiFi..
09:41:56.507 -> Connecting to WiFi..
09:41:57.016 -> Connecting to WiFi..
09:41:57.531 -> Connecting to WiFi..
09:41:58.010 -> Connecting to WiFi..
09:41:58.514 -> Connecting to WiFi..
09:41:59.017 -> Connecting to WiFi..
09:41:59.523 -> Connecting to WiFi..
09:42:00.030 -> Connecting to WiFi..
09:42:00.501 -> Connecting to WiFi..
09:42:00.838 -> [E][esp_event_loop.c:99] at_unified_cb(): at_unified evt: 4
09:42:00.838 -> 
09:42:01.008 -> Connecting to WiFi..
09:42:01.515 -> Connecting to WiFi..
09:42:02.021 -> Connecting to WiFi..
09:42:02.021 -> Connected to the WiFi network
09:42:02.021 -> IP Address: [E][esp_event_loop.c:99] at_unified_cb(): at_unified evt: 4
09:42:02.595 -> 
09:42:03.821 ->

This was generated by this sketch:

#include "AtWiFi.h"
const char* ssid = "xxxx";
const char* password =  "xxxx";
void setup() {
    while(!Serial); // Wait for Serial to be ready
    // Set WiFi to station mode and disconnect from an AP if it was previously connected
    WiFi.begin(ssid, password);
    while (WiFi.status() != WL_CONNECTED) {
        Serial.println("Connecting to WiFi..");
    Serial.println("Connected to the WiFi network");
    Serial.print("IP Address: ");
    Serial.println (WiFi.localIP()); // prints out the device's IP address
void loop() {

I was using the developer release from here It was from commit 1bf13e4.

All the libraries I used were from the links from the wiki network page form here

I used this library before and it just recently started having this problem. As a temporary solution try downloading from the last May 08,2020 commit. It should work ok as a temp solution.

So I rolled back esp-at to 8th May and that caused errors in atUnified and atWiFi. So I rolled those back to 8th May as well and finally it worked. Thanks @Dennis_Mabrey for the pointer in the right direction - I’m very pleased my brand new Wio Terminal can now connect to wifi.

16:40:41.143 -> Connecting to WiFi..
16:40:41.650 -> Connecting to WiFi..
16:40:42.158 -> Connecting to WiFi..
16:40:42.669 -> Connecting to WiFi..
16:40:42.669 -> Connected to the WiFi network
16:40:42.669 -> IP Address:

Huh that’s funny I had not rolled those back and they worked for me. Anyway glad it is working for you now. Hopefully they will resolve the esp-at library problem…