Read sms in unsynchronized mode (#33)

* Update arduino-cli binary filename

The arduino-cli binary filename was recently changed, which broke CI builds:

mv: cannot stat ‘arduino-cli-*-linux64’: No such file or directory

* Enable SMS read in unsynch mode

* Fix typo

* Fix name change of binary

* Ensure initialization of sms data end index

* Handle sender number correctly

* Keep track of start of SMS AT response

* Clear buffer

* Clarify header comment

* Adjust _smsDataEndIndex to point at end of SMS

* Revert smscharset additions

* Rewrite to save memory

* Let the available() method advance to next sms as before

* Simplify by removing smsIndexStart

Co-authored-by: per1234 <accounts@perglass.com>

src/NB_SMS.cpp

@@ -109,14 +109,12 @@ int NB_SMS::endSMS()
 
 int NB_SMS::available()
 {
-  if (_incomingBuffer.length() != 0) {
-    int nextMessageIndex = _incomingBuffer.indexOf("\r\n+CMGL: ");
+  int nextMessageIndex = _incomingBuffer.indexOf("+CMGL: ");
 
-    if (nextMessageIndex != -1) {
-      _incomingBuffer.remove(0, nextMessageIndex + 2);
-    } else {
-      _incomingBuffer = "";
-    }
+  if (nextMessageIndex != -1) {
+    _incomingBuffer.remove(0, nextMessageIndex);
+  } else {
+    _incomingBuffer = "";
   }
 
   if (_incomingBuffer.length() == 0) {
@@ -141,9 +139,12 @@ int NB_SMS::available()
   }
 
   if (_incomingBuffer.startsWith("+CMGL: ")) {
+
+    _incomingBuffer.remove(0, 7);
+
     _smsDataIndex = _incomingBuffer.indexOf('\n') + 1;
 
-    _smsDataEndIndex = _incomingBuffer.indexOf("\r\n+CMGL: ");
+    _smsDataEndIndex = _incomingBuffer.indexOf("\r\n+CMGL: ",_smsDataIndex);
     if (_smsDataEndIndex == -1) {
       _smsDataEndIndex = _incomingBuffer.length() - 1;
     }
@@ -207,13 +208,12 @@ int NB_SMS::peek()
 
 void NB_SMS::flush()
 {
-  int smsIndexStart = _incomingBuffer.indexOf(' ');
   int smsIndexEnd = _incomingBuffer.indexOf(',');
 
-  if (smsIndexStart != -1 && smsIndexEnd != -1) {
+  if (smsIndexEnd != -1) {
     while (MODEM.ready() == 0);
 
-    MODEM.sendf("AT+CMGD=%s", _incomingBuffer.substring(smsIndexStart + 1, smsIndexEnd).c_str());
+    MODEM.sendf("AT+CMGD=%s", _incomingBuffer.substring(0, smsIndexEnd).c_str());
 
     if (_synch) {
       MODEM.waitForResponse(55000);