Graph refresh rate

Issues and Errors
1

Hello,

Have started to create my first project: UNO - W5100 - MAX6675 (temperature sensor).
I am bit exploring what is the best view for a BBQ temperature reading.

I have set on my tablet a value with a reading frequency of 3 seconds and a graph with a reading frequency of 30 seconds.
My loop delay on the UNO is 3 seconds

My question: why is a bar added in the graph in a faster frequency than 30 seconds?
Can I invluence this?
I also like the historical graph but want to cover the last 3 minutes.

2

Hello. Please post your code so we can understand better what is your problem is.

3

Hi, thanks for your response. Everything is working perfectly, but I expected that setting graph frequency to 30 seconds I get 1 bar each 30 seconds. (I realize this is getting close to the historical graph). I saw the BLYNCK_READ remark in the help function but was not sure how to use this. Below my code:
(also manage to read forum instructions around publishing code) :smiley:


/*
  //http://creativecommons.org/licenses/by-sa/3.0/
  //https://github.com/mcleng/MAX6675-Library
  //http://datasheets.maximintegrated.com/en/ds/MAX6675.pdf
  */
#define BLYNK_PRINT Serial    // Comment this out to disable prints and save space
#include <SPI.h>
#include <Ethernet.h>
#include <BlynkSimpleEthernet.h>
                                
// You should get Auth Token in the Blynk App.
// Go to the Project Settings (nut icon).
char auth[] = "xxx";

#define W5100_CS  10
#define SDCARD_CS 4

#include <MAX6675.h>
// left_2_right: GND - VCC - SCK - CS - SO
//int LED1 = 9;           // Status LED Pin
int CS = 5;               // CS pin on MAX6675
int SO = 6;               // SO pin of MAX6675
int NCK = 4;              // SCK pin of MAX6675 (variable SCK cannot be used reserved for RTC) 
int units = 1;            // Units to readout temp (0 = raw, 1 = ËšC, 2 = ËšF)
float temperature = 0.0;  // Temperature output variable
int t;
// Initialize the MAX6675 Library for our chip
MAX6675 temp(CS,SO,NCK,units);
// Setup Serial output and LED Pin  
// MAX6675 Library already sets pin modes for MAX6675 chip!

void setup() {
  Serial.begin(9600);
  //pinMode(LED1, OUTPUT);
  pinMode(SDCARD_CS, OUTPUT);
  digitalWrite(SDCARD_CS, HIGH); // Deselect the SD card

  Blynk.begin(auth);
  // You can also specify server.
  // For more options, see BoardsAndShields/Arduino_Ethernet_Manual example
  //Blynk.begin(auth, "your_server.com", 8442);
  //Blynk.begin(auth, IPAddress(192,168,1,100), 8888);
}

void loop()
{
  Blynk.run();

	// Read the temp from the MAX6675
	temperature = temp.read_temp();
  t = temperature;
 Blynk.virtualWrite(22, temperature); //blynck graph=30sec (expect 1 bar for each 30 seconds)
 Blynk.virtualWrite(21, t);           //blynck value=3sec + history graph
 
	// Wait one second before reading again
	delay(3000);	
}