I have tested the code using the available Wi-Fi ready software. I have used Wifi controller software and was able to send and receive data.
But I have a problem to receive with App Inventor.
I also tested similar projects that others have done with the esp 01. But I still get error 1101 for all of them. I don't know what is the reason!
Should I consider special settings for the phone's Wi-Fi to connect the application and the Wi-Fi module?
I can think of two possible obstacles that might keep your phone from being able to connect to your IOT device through WiFi ...
Your IOT device has started its own subnetwork in its own WiFi channel, but you have not gone into your phone's Settings and asked it to scan for local WiFi connection points to get to the IOT device, or have not yet asked the phone to log onto that WiFi SSID.
This is more complex, and deals with IP subnetting, which uses masks to define IP address allocation ranges. An IP address like 192.168.4.1 would require a subnetting mask like 255.255.0.0 to admit that IP address (a Type B network), as opposed to a Type C network with a mask of 255.255.255.0 which would admit only IP addresses like 192.168.1.x or 192.168.0.x (depending on the home router's setup.)
The second possibility is at the limits of my capacity for complexity, and I am probably wrong.
