Basierend auf einem TTGO LoRa mit OLED 128×64 mit BN-880 GPS.
Anschluss
- Batterie/Lipo an den unteren Bat-Connector
- GPS an 5V/12(RX)/13(TX)/GND
Arduino mit der ESP32-Erweiterung, Board TTGO-LoRa-OLED.
Features
- 5 Hz GPS-Datenrate
- Die 5 höchsten Geschwindigkeiten, die höchste extra groß angezeigt
- Satellitenanzahl-Anzeige
Hier der Code:
//Libraries for OLED Display
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
const unsigned char ubxRate1Hz[] =
{ 0x06,0x08,0x06,0x00,0xE8,0x03,0x01,0x00,0x01,0x00 };
const unsigned char ubxRate5Hz[] =
{ 0x06,0x08,0x06,0x00,200,0x00,0x01,0x00,0x01,0x00 };
const unsigned char ubxRate10Hz[] =
{ 0x06,0x08,0x06,0x00,100,0x00,0x01,0x00,0x01,0x00 };
const unsigned char ubxRate16Hz[] =
{ 0x06,0x08,0x06,0x00,50,0x00,0x01,0x00,0x01,0x00 };
// Disable specific NMEA sentences
const unsigned char ubxDisableGGA[] =
{ 0x06,0x01,0x08,0x00,0xF0,0x00,0x00,0x00,0x00,0x00,0x00,0x01 };
const unsigned char ubxDisableGLL[] =
{ 0x06,0x01,0x08,0x00,0xF0,0x01,0x00,0x00,0x00,0x00,0x00,0x01 };
const unsigned char ubxDisableGSA[] =
{ 0x06,0x01,0x08,0x00,0xF0,0x02,0x00,0x00,0x00,0x00,0x00,0x01 };
const unsigned char ubxDisableGSV[] =
{ 0x06,0x01,0x08 ,0x00,0xF0,0x03,0x00,0x00,0x00,0x00,0x00,0x01 };
const unsigned char ubxDisableRMC[] =
{ 0x06,0x01,0x08,0x00,0xF0,0x04,0x00,0x00,0x00,0x00,0x00,0x01 };
const unsigned char ubxDisableVTG[] =
{ 0x06,0x01,0x08,0x00,0xF0,0x05,0x00,0x00,0x00,0x00,0x00,0x01 };
const unsigned char ubxDisableZDA[] =
{ 0x06,0x01,0x08,0x00,0xF0,0x08,0x00,0x00,0x00,0x00,0x00,0x01 };
#define Battadc 34
//OLED pins
#define OLED_SDA 4
#define OLED_SCL 15
#define OLED_RST 16
#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels
#define SDA 21
#define SCL 22
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RST);
bool enable_dbg;
bool sig_valid, sig_rxok;
float sig_speed, saved_spd;
int sig_sats;
float maxspeed[5];
// Cut out the wanted substring from a comma-separated string
static String extract_val(char *buf, int len, int cpos)
{
String str="";
int i,cc=0,cs=0,ce=255;
for (i=0;i 0)
sig_valid = true;
Serial.println(s);
sig_speed = s.toFloat();
saved_spd = sig_speed;
}
else if (buf[2]=='G' && buf[3]=='G' && buf[4]=='A') {
display.print(buf);
String s = extract_val(buf, pos, 7);
Serial.println(s);
sig_sats = s.toInt();
}
}
else if (c=='$') pos=0;
else if (pos < sizeof(buf))
buf[pos++] = c;
}
//Warteschleife, die ankommende Daten vom GPS Modul verarbeitet und den Status des Tasters prüft
static void smartdelay(unsigned long ms)
{
unsigned long start = millis();
do
{
while (Serial2.available()) {
char c=Serial2.read();
parse_gps(c);
if (enable_dbg) Serial.print(c);
//display.print(c);
}
//display.display();
} while (millis() - start < ms);
}
static void sendUBX( const unsigned char *progmemBytes, size_t len )
{
Serial2.write( 0xB5 ); // SYNC1
Serial2.write( 0x62 ); // SYNC2
uint8_t a = 0, b = 0;
while (len-- > 0) {
uint8_t c = ( *progmemBytes++ );
a += c;
b += a;
Serial2.write( c );
}
Serial2.write( a ); // CHECKSUM A
Serial2.write( b ); // CHECKSUM B
delay(100);
}
static void updateRate()
{
sendUBX(ubxRate5Hz, 10);
}
void setup() {
pinMode(0, INPUT_PULLUP); // button
pinMode(SCL, INPUT_PULLUP); // I2C of GPS compass
pinMode(SDA, INPUT_PULLUP);
analogSetAttenuation(ADC_0db); // control sensitivity; ADC_11db, ADC_6db, ADC_2_5db, ADC_0db
pinMode(Battadc, INPUT);
adcAttachPin(Battadc);
Serial.begin(115200); // debug
Serial2.begin(9600,SERIAL_8N1,12,13); // GPS
//reset OLED display via software
pinMode(OLED_RST, OUTPUT);
digitalWrite(OLED_RST, LOW);
delay(20);
digitalWrite(OLED_RST, HIGH);
//initialize OLED
Wire.begin(OLED_SDA, OLED_SCL);
if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3c, false, false)) { // Address 0x3C for 128x32
//Serial.println(F("SSD1306 allocation failed"));
for(;;); // Don't proceed, loop forever
}
display.setTextColor(WHITE);
display.setTextSize(1);
display.clearDisplay();
display.display();
delay(2000);
sendUBX(ubxDisableGLL, 12);
sendUBX(ubxDisableGSA, 12);
sendUBX(ubxDisableGSV, 12);
sendUBX(ubxDisableRMC, 12);
sendUBX(ubxDisableZDA, 12);
Serial2.print("$PUBX,41,1,0007,0003,19200,0*25\r\n");
Serial2.flush();
delay(100);
Serial2.end();
Serial2.begin(19200,SERIAL_8N1,12,13);
delay(1000);
updateRate();
}
void loop() {
int i;
bool spdwritten = false;
char tmp[32];
float spd;
smartdelay(0);
display.clearDisplay(); // drawString(x,y,text);? or ACROBOTIC_SSD1306 with setTextXY/putString
display.setCursor(0, 0);
if (sig_valid) {
spd = sig_speed;
sig_speed = 0.0;
// show maximum speed, with 5 places to see glitches
display.println("Geschwindigkeit (max)");
for (i=0; i<5; i++) {
if (spd > maxspeed[i] && !spdwritten) {
maxspeed[i] = spd;
spdwritten = true;
break;
}
}
for (i=0; i<5; i++) {
if (i==0)
display.setTextSize(2);
sprintf(tmp, "%4.1f km/h", maxspeed[i]);
display.println(tmp);
if (i==0)
display.setTextSize(1);
}
// show current speed
sprintf(tmp,"S%4.1f Sats %3d", saved_spd, sig_sats);
display.print(tmp);
} else {
display.println("No GPS fix.");
if (sig_rxok)
display.println("GPS RX ok");
sprintf(tmp," Sats %3d", sig_sats);
display.print(tmp);
}
display.display();
int vbatt = analogRead(Battadc);
if (digitalRead(0)==0) { // clear
for (i=0;i<5; i++)
maxspeed[i] = 0.0;
display.clearDisplay();
}
}