History Chart - No data

Solved
1

• Hardware model - ESP 8266
• Communication type - Wifi
• Iphone SE (IOS)
• Blynk server
• Blynk Library version 0.5.0

...

// Temporary variables
static char celsiusTemp[7];
static char humidityTemp[7];

...

void sendSensor()
{
  float h = dht.readHumidity();
  float t = dht.readTemperature(); 

  // Computes temperature values in Celsius and Humidity
   float hic = dht.computeHeatIndex(t, h, false);       
   dtostrf(hic, 6, 2, celsiusTemp);                     
   dtostrf(h, 6, 2, humidityTemp);
 
  if (isnan(h) || isnan(t)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }
  Blynk.virtualWrite(V2, humidityTemp);
  Blynk.virtualWrite(V1, celsiusTemp);
  blinkLedWidget();
}

...

Good morning!
Can you tell me what I’m doing wrong?
In IOS when I add V1 and V2 to History Chart, it write “no data”!
But in “value display” temperature and humidity is available correct (27.34 etc.)

2

Assuming you meen SuperChart, not its predecessor History Graph (or possibly both… can’t remember the old one now :stuck_out_tongue_winking_eye: )… depending on the scale you are looking at, it will take some time to populate the data stream.

3

History Graph. The problem in value - type float does not appear, but if i writing in channel V1 the value type int, on the graph the chart is appear

4

The same - in Gauge and graph.

5

Hello. Try to print values to serial output and check the values, most probably you send not floats. Also history graph has 1 minute delay, maybe this is the issue.

6

Sounds like you are running some older versions of App… You need to keep them current to a point. Be aware that the History Graph has been “replaced” with the Super Chart in newer App versions.

7
  1. I print value in chanel V1 in “Value Display” and “Label Value” - they are appear.
  2. I make the SUB change the led state and write it to channel V3 - it is appear in History graph (delay 2 minute).
  3. If I rounded the values in V1 and V2 - they are appear in history graph
8
  1. History Graph - Value appear just in Display
  2. History Graph + LED - LED value appear in History Graph

library and IOS application is newest

9

History Graph Pin mode
History Graph LED

10

@Piroteh please post the serial output from your hardware. I’ll repeat - from what I see you probably send not floats but strings. Please check you haven’t ‘space’ char in data you send.

Try to print

char humidityTemp[7]

to serial output. I bet it has space in it. Also, you don’t need to send strings. You may send floats directly.

11

Thank’s! It was a space above the value: _27.23

You can close this topic.

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