Fix #362 by @a-f-G-U-C - I was mispelling NMEA ;-)

src/gps/NMEAGPS.cpp

@@ -0,0 +1,81 @@
+#include "NMEAGPS.h"
+#include "configuration.h"
+#include "timing.h"
+
+static int32_t toDegInt(RawDegrees d)
+{
+    int32_t degMult = 10000000; // 1e7
+    int32_t r = d.deg * degMult + d.billionths / 100;
+    if (d.negative)
+        r *= -1;
+    return r;
+}
+
+void NMEAGPS::loop()
+{
+    while (_serial_gps->available() > 0) {
+        int c = _serial_gps->read();
+        // Serial.write(c);
+        reader.encode(c);
+    }
+
+    uint32_t now = timing::millis();
+    if ((now - lastUpdateMsec) > 20 * 1000) { // Ugly hack for now - limit update checks to once every 20 secs (but still consume
+                                              // serial chars at whatever rate)
+        lastUpdateMsec = now;
+
+        auto ti = reader.time;
+        auto d = reader.date;
+        if (ti.isUpdated() && ti.isValid() && d.isValid()) {
+            /* Convert to unix time
+    The Unix epoch (or Unix time or POSIX time or Unix timestamp) is the number of seconds that have elapsed since January 1, 1970
+    (midnight UTC/GMT), not counting leap seconds (in ISO 8601: 1970-01-01T00:00:00Z).
+    */
+            struct tm t;
+            t.tm_sec = ti.second();
+            t.tm_min = ti.minute();
+            t.tm_hour = ti.hour();
+            t.tm_mday = d.day();
+            t.tm_mon = d.month() - 1;
+            t.tm_year = d.year() - 1900;
+            t.tm_isdst = false;
+            perhapsSetRTC(t);
+
+            isConnected = true; // we seem to have a real GPS (but not necessarily a lock)
+        }
+
+        uint8_t fixtype = reader.fixQuality();
+        hasValidLocation = ((fixtype >= 1) && (fixtype <= 5));
+
+        if (reader.location.isUpdated()) {
+            if (reader.altitude.isValid())
+                altitude = reader.altitude.meters();
+
+            if (reader.location.isValid()) {
+                auto loc = reader.location.value();
+                latitude = toDegInt(loc.lat);
+                longitude = toDegInt(loc.lng);
+            }
+            // Diminution of precision (an accuracy metric) is reported in 10^2 units, so we need to scale down when we use it
+            if (reader.hdop.isValid()) {
+                dop = reader.hdop.value();
+            }
+            if (reader.course.isValid()) {
+                heading =
+                    reader.course.value() * 1e3; // Scale the heading (in degrees * 10^-2) to match the expected degrees * 10^-5
+            }
+            if (reader.satellites.isValid()) {
+                numSatellites = reader.satellites.value();
+            }
+
+            // expect gps pos lat=37.520825, lon=-122.309162, alt=158
+            DEBUG_MSG("new NMEA GPS pos lat=%f, lon=%f, alt=%d, hdop=%f, heading=%f\n", latitude * 1e-7, longitude * 1e-7,
+                      altitude, dop * 1e-2, heading * 1e-5);
+        }
+
+        // Notify any status instances that are observing us
+        const meshtastic::GPSStatus status =
+            meshtastic::GPSStatus(hasLock(), isConnected, latitude, longitude, altitude, dop, heading, numSatellites);
+        newStatus.notifyObservers(&status);
+    }
+}