How to save all historical superchart?

Solved
1

Hi. I am using an DHT 11 with ESP8266 and Blynk. I am having this problem: I added an superchart and it worked ok, but if I open other app on my phone, when back to blynk the superchart restarts the counting and I can’t visualize the historical measurements. For example: I am monitoring the superchart and needs to answer a conversation on whatsapp, when I reopen the blynk, the graphs show the data initiating at the time that I reopened the Blynk App, as I ilustrate on the image.

image
image1545×783 142 KB

So, if I wish to export an csv file for, as example, 1 hour of measurements, I can’t open other app for 1 hour? The Blynk app needs to be in first plane to save all historical superchart? Thank you.

My hardware is an Android mobile phone, an ESP8266 and an DHT11 sensor. I am using the Blynk Server.

The code:


#include <ESP8266WiFi.h>
#include <BlynkSimpleEsp8266.h>
#include <DHT.h>
 
char auth[] = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
 
char ssid[] = "MyNet";
char pass[] = "password123";
 
#define DHTPIN 5         
 
#define DHTTYPE DHT11 
 
DHT dht(DHTPIN, DHTTYPE);
BlynkTimer timer;

void sendSensor()
{
  float h = dht.readHumidity();
  float t = dht.readTemperature(); // 
 
  if (isnan(h) || isnan(t)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }
  Blynk.virtualWrite(V5, t);
  Blynk.virtualWrite(V6, h);
}
 
void setup()
{
  Serial.begin(9600);
 
  Blynk.begin(auth, ssid, pass);
 
  dht.begin();
  timer.setInterval(1000L, sendSensor);
}
 
void loop()
{
  Blynk.run();
  timer.run();
}
2

That shouldn’t be happening.
I think you need to provide much ,ore detail (essentially, all the detail that you were asked to provide when you created this topic), along with screenshots, code etc.

Pete.

3

Thank you Pete. I edited the post.

4

You’re using Live View, and that’s how it works.
If you set your SuperChart up to show other time periods, such as 15 minutes, 1 Hr, 6 Hrs etc, then your data views would be more useable.

When it comes to exporting, the highest granularity is 1 data point per minute. All data sent to the server during a 1 minute period is buffered, and the average written to the database.

Pete.

5

Thank you, Pete. I am using the 15 minute view and now I can tap and drag the lines on the graph to view the previously measured data when I reopen the blynk, even using other applications on the phone.