ESP8266 Community Forum

I have two ESP8266-01.
When I try a program (f.e. https://www.arduino.cc/en/Reference/WiFiClient) then this program loads OK, but the program execution in NOK. This happens with both ESP's.

I check my ESP's with the Arduino IDE: File -> Examples -> ESP8266 -> CheckFlashConfig and get the following result:



I have been using these ESP's with NodeMCU before. Could that be the cause of the problem?
What should I do to flash them right?

If you check this sketch, it simply giving the error because "ideSize != realSize".
You need to select 1M Flash size in the IDE menu.

martinayotte wrote:If you check this sketch, it simply giving the error because "ideSize != realSize".
You need to select 1M Flash size in the IDE menu.

You are right. Thanks.