ESP8266 Community Forum

- Sun May 02, 2021 12:26 am #91301 Hi,

I'm using AT commands on an ESP01 board with 1MB flash. I can connect to some HTTPS sites, but not others.

I'm using SDK 1.7.4:

AT+GMR
AT version:1.7.4.0(May 11 2020 19:13:04)
SDK version:3.0.4(9532ceb)
compile time:May 27 2020 10:12:17
Bin version(Wroom 02):1.7.4

Note that I have increased the SSL buffer size to 8192:

AT+CIPSSLSIZE?
+CIPSSLSIZE:8192
OK

Below is the output for sites that do work:

AT+CIPSTART="SSL","www.google.com",443
CONNECT

AT+CIPSTART="SSL","www.yahoo.com",443
CONNECT

And below is the output for sites that do not work:

AT+CIPSTART="SSL","www.wikimedia.org",443
CLOSED

AT+CIPSTART="SSL","www.dictionary.com",443
CLOSED

Do you know why it's not working for those sites, and how to fix?

Thanks a lot,

Julien

- Mon May 03, 2021 12:37 am #91306 AT firmware doesn't support TLS 1.2
if your Arduino is ARM, then you can use the SSLClient library over WiFiEsp or my WiFiEspAT library