Blynk and NodeMCU ESP8622 error

[PeteKnight]

@Tomreef

The Graphs however are configured by the Web Dashboard, which I found a bit messy, as the screen for Web display is limited due to multiple command boxes - would benefit from being able to address the Wed View independently so this can be made mode presentable

I don’t understand this comment.
Presumably you’re talking about Charts in the web console?
The Superchart is the equivalent widget in the mobile app.
Web widgets are configured in the web console, app widgets are configured in the app. Both inherit their min/max values from the datastream setup, unless this is overridden.

The free subscription allows just one datastream per Chart/Superchart.

Comments on your code…

@Tomreef

long a;

It’s always best to use meaningful variable names, in this case “distance” would have been better than “a”

@Tomreef

// This function is called every time the device is connected to the Blynk.Cloud
BLYNK_CONNECTED()
{
  // Change Web Link Button message to "Congratulations!"
  Blynk.setProperty(V3, "offImageUrl", "https://static-image.nyc3.cdn.digitaloceanspaces.com/general/fte/congratulations.png");
  Blynk.setProperty(V3, "onImageUrl",  "https://static-image.nyc3.cdn.digitaloceanspaces.com/general/fte/congratulations_pressed.png");
  Blynk.setProperty(V3, "url", "https://docs.blynk.io/en/getting-started/what-do-i-need-to-blynk/how-quickstart-device-was-made");
}

This code is left-over from the QuickStart sketch and needs to be deleted, as it could cause issues with whatever widget is attached to V3.

@Tomreef

  // this is code to get didtance reading and then print with CR to Serial Monitor for checking
  a=sr04.Distance(); // reading the distance from Ultrasonic
  a = a + calibration;  //calibration if needed
  Serial.print(a); // printing to Serial Monitor
  Serial.println("cm");//The difference between "Serial.print" and "Serial.println" 
                        //is that "Serial.println" can change lines.
  delay(250); // delay set to 250 ms to speed reading

This code should not be in your void loop. It should be in the myTimerEvent function, and the delay should not be included at all in your sketch. The frequency of readings should be controlled by your timer.

@Tomreef

// here is code to switch RED 0n ***************************************************
BLYNK_WRITE(V0) // Executes when the value of virtual pin 0 changes
 {
  if(param.asInt() == 1)
    {     
    digitalWrite(2,HIGH);  // Set digital pin 2 HIGH // execute this code if the switch widget is now ON
    }
  else
    {      
    digitalWrite(2,LOW);  // Set digital pin 2 LOW - note this physically appears on D4 
    }
 }

This approach is very clunky. You’d be far better assigning the incoming widget value obtained via param.asInt() to a variable and using that directly in your digitalWrite command…

// here is code to switch RED 0n ***************************************************
BLYNK_WRITE(V0) // Executes when the value of virtual pin 0 changes
{
  int red_led = param.asInt()
  digitalWrite(2,red_led); 
 }

or if your LED is active LOW (inverted) then use the logical NOT operator (!) to invert the value…

// here is code to switch RED 0n ***************************************************
BLYNK_WRITE(V0) // Executes when the value of virtual pin 0 changes
{
  int red_led = param.asInt()
  digitalWrite(2,!red_led); 
 }

Pete.

[Tomreef]

Well Pete - I did say it wasn’t pretty - not bad for a first timer though

Thanks for your suggestion and I will take them on board with my next project/investigation

My comments relating to the Web Dashboard are that you can only see this inside the Blynk Console with the left hand menu and top options etc still available. I was hoping there was a button or switch so that i could view the Web Dashboard page by itself without the surrounding clutter when in RUN mode so it can be a device specific user page (like the mobile app that goes into USER mode after exiting the Editing mode - there maybe an option for this

hope this clarifies my comments

Tom

[PeteKnight]

@Tomreef

I will take them on board with my next project/investigation

You need to sort-out the void loop on THIS project, otherwise you’ll run into issues long-term

@Tomreef

I was hoping there was a button or switch so that i could view the Web Dashboard page by itself without the surrounding clutter when in RUN mode so it can be a device specific user page

It sounds like you’re asking for a kiosk view, which isn’t currently available.

Pete.