1. Fix 'spurious close' by adding close() in open(). 'spurious close' gets frequent and cannot ignore when send() changes to asynchronous. User can retry open() until 'spurious close' gets true.
2. Allow only one actively sending socket because:
(1) ESP8266 AT packets 'SEND OK'/'SEND FAIL' are not associated with socket ID. No way to tell them.
(2) In original implementation, ESP8266::send() is synchronous, which implies only one actively sending socket.
3. Register 'SEND OK'/'SEND FAIL' oobs, like others in ESP8266::ESP8266 constructor. Don't get involved in oob management with send status because ESP8266 modem possibly doesn't reply these packets on error case.
4. Now that ESP8266::send() changes to asynchronous, drop the code with _parser.recv("SEND OK")/_parser.recv("SEND FAIL"). _parser.recv("SEND OK")/_parser.recv("SEND FAIL") and 'SEND OK'/'SEND FAIL' oobs both consume 'SEND OK'/'SEND FAIL' packets and complicate flow control.
We are now checking if ESP8266 has confirmed receiving data over serial
port with an undocumented (but existing) "Recv x bytes" message. Next we
are explicitly waiting for an official "SEND OK".
"ns_types.h" results in build failure when networking feature is ignored with
.mbedignored. ESP8266 component should be enabled only when NSAPI is present.
mbed.h has 'using namespace mbed;', hence some of the files skip
adding required namespace to the code, it is always good to specify the
namespace around the elements in header and `using namespace` in
specific CPP files, instead of all
Michal Paszta
Chun-Chieh Li
Antti Yli-Tokola
Dominika Maziec
Cruz Monrreal
Veijo Pesonen
Seppo Takalo
Deepika