[OoB 5.13] Need to change ESP8266 driver's support AT firmware version

[coisme]

Description

This issue affects ESP8266 module which AT firmware version is less than 1.6 and Mbed OS 5.13.0-rc1 or later.

According to the Firmware version section in ESP8266 driver's README.md, the driver supports AT firmware versions 1.3.0 to 1.7.0.

However, this commit 1c23c5b uses AT+CWCOUNTRY command in the _init() function. This _init() function is called in scan() and connect(). The AT+CWCOUNTRY command was introduced from AT command v1.6, according to vendor's release note. Therefore, if a user uses the module which AT firmware version is less than 1.6, fails to connect to Wi-Fi.

What I did

I tried mbed-os-example-wifi on LPC55S69_NS with ESP8266 AT firmware v1.3.0. With mbed-os-5.12.4, the example program worked. However, the example program didn't work with master branch (mbed-os-5.13). After updating AT firmware to v1.6.2, the example program worked with master branch.

Issue request type

[ ] Question
[ ] Enhancement
[X] Bug

[ciarmcom]

Internal Jira reference: https://jira.arm.com/browse/MBOCUSTRIA-1276

[ciarmcom]

Thank you for raising this detailed GitHub issue. I am now notifying our internal issue triagers.
Internal Jira reference: https://jira.arm.com/browse/IOTOSM-2142