Cansat
/
esp32_Adafruit_GPS
2
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Change GPS time alignment 

Detect time first character of NMEA sentence received and treat that as corresponding to GPS timestamp in the sentence. Still some latency, but less than using the end of the receipt.
This commit is contained in:
Rick Sellens 2019-09-29 12:26:01 -04:00
parent 7bc6e51338
commit 1f8c5a58d7
2 changed files with 11 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
Adafruit_GPS.cpp
View File

@ -103,7 +103,7 @@ boolean Adafruit_GPS::parse(char *nmea) {
fixquality = atoi(p); fixquality = atoi(p);
if(fixquality > 0){ if(fixquality > 0){
fix = true; fix = true;
lastFix = recvdTime; lastFix = sentTime;
} else } else
fix = false; fix = false;
} }
@ -178,7 +178,7 @@ boolean Adafruit_GPS::parse(char *nmea) {
day = fulldate / 10000; day = fulldate / 10000;
month = (fulldate % 10000) / 100; month = (fulldate % 10000) / 100;
year = (fulldate % 100); year = (fulldate % 100);
lastDate = recvdTime; lastDate = sentTime;
} }
return true; return true;
} }
@ -227,7 +227,7 @@ void Adafruit_GPS::parseTime(char *p) {
p = strchr(p, '.')+1; p = strchr(p, '.')+1;
milliseconds = atoi(p); milliseconds = atoi(p);
lastTime = recvdTime; lastTime = sentTime;
} }
/**************************************************************************/ /**************************************************************************/
@ -343,7 +343,7 @@ boolean Adafruit_GPS::parseLonDir(char *p) {
boolean Adafruit_GPS::parseFix(char *p) { boolean Adafruit_GPS::parseFix(char *p) {
if (p[0] == 'A'){ if (p[0] == 'A'){
fix = true; fix = true;
lastFix = recvdTime; lastFix = sentTime;
} }
else if (p[0] == 'V') else if (p[0] == 'V')
fix = false; fix = false;
@ -392,6 +392,8 @@ float Adafruit_GPS::secondsSinceDate() {
*/ */
/**************************************************************************/ /**************************************************************************/
char Adafruit_GPS::read(void) { char Adafruit_GPS::read(void) {
static uint32_t firstChar = 0; // first character received in current sentence
uint32_t tStart = millis(); // as close as we can get to time char was sent
char c = 0; char c = 0;
if (paused) return c; if (paused) return c;
@ -434,8 +436,12 @@ char Adafruit_GPS::read(void) {
lineidx = 0; lineidx = 0;
recvdflag = true; recvdflag = true;
recvdTime = millis(); // time we got the end of the string recvdTime = millis(); // time we got the end of the string
sentTime = firstChar;
firstChar = 0; // there are no characters yet
return c; // wait until next character to set time
} }
if(firstChar == 0) firstChar = tStart;
return c; return c;
} }

1
Adafruit_GPS.h
View File

@ -187,6 +187,7 @@ class Adafruit_GPS {
uint32_t lastTime = 2000000000L; // millis() when last time received uint32_t lastTime = 2000000000L; // millis() when last time received
uint32_t lastDate = 2000000000L; // millis() when last date received uint32_t lastDate = 2000000000L; // millis() when last date received
uint32_t recvdTime = 2000000000L; // millis() when last full sentence received uint32_t recvdTime = 2000000000L; // millis() when last full sentence received
uint32_t sentTime = 2000000000L; // millis() when first character of last full sentence received
boolean paused; boolean paused;
uint8_t parseResponse(char *response); uint8_t parseResponse(char *response);