I use the following arduino code to send lat/log to cayenne using MQTT
typedef struct {
char Recno1{2};
char Date[7];
char Time[7];
float Latitude;
float Longitude;
int ActualCourse;
int CalcCourse;
float Speed;
} RECORD1;
RECORD1 rec1;
Cayenne.virtualWrite(1, rec1.Latitude, "text", "");
Cayenne.virtualWrite(2, rec1.Longitude, "text", "");
If I Serial.print these fields, they show data to 5 decimal places.
However Cayenne shows three decimals and two zeros.
![Untitled](https://global.discourse-cdn.com/business5/uploads/mydevices/original/2X/9/98d28136a4294119b2c7a1cdd56016724a533b04.jpeg)
When I download the chart data, it shows only 3 decimals
How do I get the full 5 decimals, as I need 4-5 decimals of accuracy
can you post the entire code.
Here is the code
//#define CAYENNE_DEBUG
#define CAYENNE_PRINT Serial
#include <CayenneMQTTESP8266.h>
#include <SoftwareSerial.h>
#include <Wire.h>
#include <SPI.h>
#ifdef __AVR__
#include <avr/power.h>
#endif
// WiFi network info.
char ssid[] = "?????";
char wifiPassword[] = "?????";
// Cayenne authentication info. This should be obtained from the Cayenne Dashboard.
char username[] = "?????";
char password[] = "?????";
char clientID[] = "?????";
unsigned long lastMillis = 0;
typedef struct {
float Latitude = 33.12345;
float Longitude = -151.78901;
int ActualCourse = 60;
int CalcCourse = 359;
float Speed = 4.7;
} RECORD1;
RECORD1 rec1;
void setup()
{
Serial.begin(115200);
Cayenne.begin(username, password, clientID, ssid, wifiPassword);
while (!Serial) { delay(1); } // wait until serial console is open, remove if not tethered to computer
}
void loop() {
Cayenne.loop();
SendToCayenne();
}
void SendToCayenne()
{
//Publish data every 30 seconds (30000 milliseconds). Change this value to publish at a different interval.
if (millis() - lastMillis > 30000) {
lastMillis = millis();
//Write data to Cayenne here.
Serial.print("Cayenne Latitude");Serial.println(rec1.Latitude,5);
Cayenne.virtualWrite(1, rec1.Latitude, "text", "");
Cayenne.virtualWrite(2, rec1.Longitude, "text", "");
Cayenne.virtualWrite(3, rec1.CalcCourse, "analog_sensor", "null");
Cayenne.virtualWrite(4, rec1.Speed, "wind_speed", "kmh");
Cayenne.virtualWrite(17, rec1.ActualCourse, "analog_sensor", "null");
}
}
use dtostrf()
which will convert a float to a char array and then send it.
Thanks for that. It worked!
The ironic thing is that another program sends the data to this program as char fields, and I was converting to float to send to cayenne
I’m trying to do something like this right now, however I want the precision to be as precise as possible. However when I try sending the data to Cayenne they cut off part of the precision. Even though I am sending it as a character array.