Add a new GPS model CM121. (#7852)

* Add a new GPS model CM121.

* Add CM121 to Unicore.

* Trunk fixes, remove unneded NMEA lines

---------

Co-authored-by: Tom Fifield <tom@tomfifield.net>

src/gps/GPS.cpp

@@ -808,6 +808,14 @@ bool GPS::setup()
             } else {
                 LOG_INFO("GNSS module configuration saved!");
             }
+        } else if (gnssModel == GNSS_MODEL_CM121) {
+            // only ask for RMC and GGA
+            // enable GGA
+            _serial_gps->write("$CFGMSG,0,0,1,1*1B\r\n");
+            delay(250);
+            // enable RMC
+            _serial_gps->write("$CFGMSG,0,4,1,1*1F\r\n");
+            delay(250);
         }
         didSerialInit = true;
     }
@@ -1240,9 +1248,15 @@ GnssModel_t GPS::probe(int serialSpeed)
     _serial_gps->write("$PUBX,40,GSV,0,0,0,0,0,0*59\r\n");
     _serial_gps->write("$PUBX,40,VTG,0,0,0,0,0,0*5E\r\n");
     delay(20);
+    // Close NMEA sequences on CM121
+    _serial_gps->write("$CFGMSG,0,1,0,1*1B\r\n");
+    _serial_gps->write("$CFGMSG,0,2,0,1*18\r\n");
+    _serial_gps->write("$CFGMSG,0,3,0,1*19\r\n");
+    delay(20);
 
-    // Unicore UFirebirdII Series: UC6580, UM620, UM621, UM670A, UM680A, or UM681A
-    std::vector<ChipInfo> unicore = {{"UC6580", "UC6580", GNSS_MODEL_UC6580}, {"UM600", "UM600", GNSS_MODEL_UC6580}};
+    // Unicore UFirebirdII Series: UC6580, UM620, UM621, UM670A, UM680A, or UM681A,or CM121
+    std::vector<ChipInfo> unicore = {
+        {"UC6580", "UC6580", GNSS_MODEL_UC6580}, {"UM600", "UM600", GNSS_MODEL_UC6580}, {"CM121", "CM121", GNSS_MODEL_CM121}};
     PROBE_FAMILY("Unicore Family", "$PDTINFO", unicore, 500);
 
     std::vector<ChipInfo> atgm = {

src/gps/GPS.h

@@ -31,7 +31,8 @@ typedef enum {
     GNSS_MODEL_MTK_PA1616S,
     GNSS_MODEL_AG3335,
     GNSS_MODEL_AG3352,
-    GNSS_MODEL_LS20031
+    GNSS_MODEL_LS20031,
+    GNSS_MODEL_CM121
 } GnssModel_t;
 
 typedef enum {