I'm having an interesting problem with what appears to be an odd interaction with U8GLIB and TinyGPS++ on a Teensy 3.1. Here is the code:
With the code as it is, I get the following output on Serial, and the display is updated when it does get good GPS data. Notice all the failed checksums.
If I comment out the UpdateDisplay() call in loop() I get the following on Serial (and of course the display isn't updated.) Note there are no failed checksums.
For some reason, the call to the U8GLIB picture loop (UpdateDisplay() function) is affecting the reading of the GPS data on Serial1.
Any ideas?
Code:
// SPI library
#include <SPI.h>
// GPS library
#include <TinyGPS++.h>
// Display library
#include <U8glib.h>
// Debugging statements to serial monitor
#define DEBUG
// Display
//U8GLIB_NHD27OLED_2X_GR u8g(10, 15); // U8GLIB_NHD27OLED_GR(cs, a0 [, reset]) - Hardware SPI 2x speed
//U8GLIB_NHD27OLED_GR u8g(10, 15); // U8GLIB_NHD27OLED_GR(cs, a0 [, reset]) - Hardware SPI
U8GLIB_NHD27OLED_GR u8g(13, 11, 10, 15); // U8GLIB_NHD27OLED_GR(sck, mosi, cs, a0 [, reset]) - Software SPI
// digital pin definitions
const int GPS_RX_PIN = 0; // GPS serial receive data
const int GPS_TX_PIN = 1; // GPS serial transmit data
const int OLEDdata = 15; // Data to OLED
// GPS/Trip
TinyGPSPlus gps;
unsigned long last = 0UL;
float latitude, longitude;
int speed, course, altitude;
// Time
int yr;
byte mo, dy, hr, mn, sc;
// End Global Variables
//
// Start setup
//
void setup() {
Serial.begin(115200);
Serial1.begin(115200); // GPS
#ifdef DEBUG
delay(4000); // testing delay
Serial.println(F("Begin setup"));
#endif
#ifdef DEBUG
Serial.println(F("Display start"));
#endif
// Start the display
u8g.begin();
u8g.setColorIndex(10); // 15 = max intensity for GR display, 1 = on for BW
u8g.setContrast(63); // 0-127
#ifdef DEBUG
Serial.println(F("Pin init"));
#endif
pinMode(OLEDdata, OUTPUT); // Data out to OLED display - SPI2_SI on NHD display
#ifdef DEBUG
Serial.println(F("End setup"));
#endif
} // End setup()
void UpdateDisplay() {
// picture loop
u8g.firstPage();
do {
DisplayDateTime();
DisplayGPS();
}
while(u8g.nextPage());
}
void loop() {
UpdateGPS();
UpdateDisplay();
}
void UpdateGPS() {
while (Serial1.available() > 0)
gps.encode(Serial1.read());
if (gps.location.isUpdated())
{
Serial.print(F("LOCATION Fix Age="));
Serial.print(gps.location.age());
Serial.print(F(" Lat="));
Serial.print(gps.location.lat(), 6);
Serial.print(F(" Long="));
Serial.println(gps.location.lng(), 6);
latitude = gps.location.lat();
longitude = gps.location.lng();
}
else if (gps.date.isUpdated())
{
Serial.print(F("DATE Fix Age="));
Serial.print(gps.date.age());
Serial.print(F(" Year="));
Serial.print(gps.date.year());
Serial.print(F(" Month="));
Serial.print(gps.date.month());
Serial.print(F(" Day="));
Serial.println(gps.date.day());
dy = gps.date.day();
mo = gps.date.month();
yr = gps.date.year();
}
else if (gps.time.isUpdated())
{
Serial.print(F("TIME Fix Age="));
Serial.print(gps.time.age());
Serial.print(F(" Hour="));
Serial.print(gps.time.hour());
Serial.print(F(" Minute="));
Serial.print(gps.time.minute());
Serial.print(F(" Second="));
Serial.println(gps.time.second());
hr = gps.time.hour();
mn = gps.time.minute();
sc = gps.time.second();
}
else if (gps.speed.isUpdated())
{
Serial.print(F("SPEED Fix Age="));
Serial.print(gps.speed.age());
Serial.print(F(" MPH="));
Serial.println(gps.speed.mph());
speed = gps.speed.mph();
}
else if (gps.course.isUpdated())
{
Serial.print(F("COURSE Fix Age="));
Serial.print(gps.course.age());
Serial.print(F(" Deg="));
Serial.println(gps.course.deg());
course = gps.course.deg();
}
else if (gps.altitude.isUpdated())
{
Serial.print(F("ALTITUDE Fix Age="));
Serial.print(gps.altitude.age());
Serial.print(F(" Feet="));
Serial.println(gps.altitude.feet());
altitude = gps.altitude.feet();
}
else if (millis() - last > 5000)
{
Serial.println();
if (gps.location.isValid())
Serial.print(F("DIAGS Chars="));
Serial.print(gps.charsProcessed());
Serial.print(F(" Sentences-with-Fix="));
Serial.print(gps.sentencesWithFix());
Serial.print(F(" Failed-checksum="));
Serial.print(gps.failedChecksum());
Serial.print(F(" Passed-checksum="));
Serial.println(gps.passedChecksum());
if (gps.charsProcessed() < 10)
Serial.println(F("WARNING: No GPS data. Check wiring."));
last = millis();
Serial.println();
}
}
void DisplayGPS() {
// Print the MPH
if (speed < 2) { // Show the speed as 0 if < 2 due to GPS error
speed = 0;
}
u8g.setFont(u8g_font_ncenR24n);
if (speed < 10 ) {
u8g.setPrintPos(56, 40);
}
else if (speed < 100 && speed >= 10 ) {
u8g.setPrintPos(49, 40);
}
else {
u8g.setPrintPos(42, 40);
}
u8g.print(speed);
// Print the heading
u8g.setFont(u8g_font_10x20r);
u8g.setPrintPos(53, 13);
u8g.print(course);
u8g.setFont(u8g_font_tpssr);
// Print the altitude
u8g.setPrintPos(48, 53);
u8g.print(altitude,0);
// Print the lat/long
u8g.setPrintPos(0, 63);
u8g.print(latitude,6);
u8g.setPrintPos(65, 63);
u8g.print(longitude,6);
}
void DisplayDateTime() {
u8g.setFont(u8g_font_tpssr);
// display the time
if ( hr < 10 ) {
u8g.setPrintPos(6, 33);
}
else {
u8g.setPrintPos(0, 33);
}
u8g.print(hr);
u8g.setPrintPos(13, 31);
u8g.print(":");
if (mn < 10 ) {
u8g.setPrintPos(18, 33);
u8g.print("0");
u8g.setPrintPos(24, 33);
}
else {
u8g.setPrintPos(18, 33);
}
u8g.print(mn);
// display the date
if ( mo < 10 ) {
u8g.setPrintPos(6, 45);
}
else {
u8g.setPrintPos(0, 45);
}
u8g.print(mo);
u8g.setPrintPos(11, 45);
u8g.print("/");
if (dy < 10 ) {
u8g.setPrintPos(18, 45);
u8g.print("0");
u8g.setPrintPos(24, 45);
}
else {
u8g.setPrintPos(18, 45);
}
u8g.print(dy);
}With the code as it is, I get the following output on Serial, and the display is updated when it does get good GPS data. Notice all the failed checksums.
If I comment out the UpdateDisplay() call in loop() I get the following on Serial (and of course the display isn't updated.) Note there are no failed checksums.
For some reason, the call to the U8GLIB picture loop (UpdateDisplay() function) is affecting the reading of the GPS data on Serial1.
Any ideas?
