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DHT11 Sensor with RPI

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  • J jsulm
    2 Nov 2020, 06:50

    @helloworldddd What exactly does not work? Is DHTread(self) called? If so, what does it print?

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    helloworldddd
    wrote on 2 Nov 2020, 07:08 last edited by
    #3

    @jsulm i cant figure out on how to plot a graph and display it with PlotWidget and pyqtgraph with the values taken from the sensor !

    J 1 Reply Last reply 2 Nov 2020, 07:12
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    • H helloworldddd
      2 Nov 2020, 07:08

      @jsulm i cant figure out on how to plot a graph and display it with PlotWidget and pyqtgraph with the values taken from the sensor !

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      jsulm
      Lifetime Qt Champion
      wrote on 2 Nov 2020, 07:12 last edited by
      #4

      @helloworldddd I never used PlotWidget or pyqtgraph and those are not part of Qt.
      You should consider reading some documentation/tutorial like https://www.learnpyqt.com/courses/graphics-plotting/plotting-pyqtgraph/
      Or check https://doc.qt.io/qt-5/qtcharts-index.html which is part of Qt.

      https://forum.qt.io/topic/113070/qt-code-of-conduct

      H 1 Reply Last reply 2 Nov 2020, 08:04
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      • J jsulm
        2 Nov 2020, 07:12

        @helloworldddd I never used PlotWidget or pyqtgraph and those are not part of Qt.
        You should consider reading some documentation/tutorial like https://www.learnpyqt.com/courses/graphics-plotting/plotting-pyqtgraph/
        Or check https://doc.qt.io/qt-5/qtcharts-index.html which is part of Qt.

        H Offline
        H Offline
        helloworldddd
        wrote on 2 Nov 2020, 08:04 last edited by
        #5

        @jsulm ive also read up on using .csv files to plot the graph by using the values recorded. the examples shown were only fixed values. how do i plot the graph with values that just being recorded ?

        J 1 Reply Last reply 2 Nov 2020, 08:12
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        • H helloworldddd
          2 Nov 2020, 08:04

          @jsulm ive also read up on using .csv files to plot the graph by using the values recorded. the examples shown were only fixed values. how do i plot the graph with values that just being recorded ?

          J Offline
          J Offline
          jsulm
          Lifetime Qt Champion
          wrote on 2 Nov 2020, 08:12 last edited by
          #6

          @helloworldddd said in DHT11 Sensor with RPI:

          how do i plot the graph with values that just being recorded ?

          Well, use the recorded values instead of the values from csv. I really don't get what exactly the problem is! Can you please be more specific?

          https://forum.qt.io/topic/113070/qt-code-of-conduct

          H 1 Reply Last reply 2 Nov 2020, 08:15
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          • J jsulm
            2 Nov 2020, 08:12

            @helloworldddd said in DHT11 Sensor with RPI:

            how do i plot the graph with values that just being recorded ?

            Well, use the recorded values instead of the values from csv. I really don't get what exactly the problem is! Can you please be more specific?

            H Offline
            H Offline
            helloworldddd
            wrote on 2 Nov 2020, 08:15 last edited by
            #7

            @jsulm how do i get the recorded values and put it into a list and limit the list to like in 2 hour intervals with 20 mins as every point. and the time, which is the x axis to self increment?

            J 1 Reply Last reply 2 Nov 2020, 08:18
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            • H helloworldddd
              2 Nov 2020, 08:15

              @jsulm how do i get the recorded values and put it into a list and limit the list to like in 2 hour intervals with 20 mins as every point. and the time, which is the x axis to self increment?

              J Offline
              J Offline
              jsulm
              Lifetime Qt Champion
              wrote on 2 Nov 2020, 08:18 last edited by
              #8

              @helloworldddd said in DHT11 Sensor with RPI:

              how do i get the recorded values and put it into a list and limit the list to like in 2 hour intervals with 20 mins as every point

              What is your level of experience with programming? Do you know how you can add values to a list in Python? Please don't forget that this is Qt forum not Python... "limit the list to like in 2 hour intervals with 20 mins" - this is simple math to calculate how many elements the list should contain (max).

              You never answered my question: "Is DHTread(self) called? If so, what does it print?" Can you please answer it?

              https://forum.qt.io/topic/113070/qt-code-of-conduct

              H 1 Reply Last reply 2 Nov 2020, 08:27
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              • J jsulm
                2 Nov 2020, 08:18

                @helloworldddd said in DHT11 Sensor with RPI:

                how do i get the recorded values and put it into a list and limit the list to like in 2 hour intervals with 20 mins as every point

                What is your level of experience with programming? Do you know how you can add values to a list in Python? Please don't forget that this is Qt forum not Python... "limit the list to like in 2 hour intervals with 20 mins" - this is simple math to calculate how many elements the list should contain (max).

                You never answered my question: "Is DHTread(self) called? If so, what does it print?" Can you please answer it?

                H Offline
                H Offline
                helloworldddd
                wrote on 2 Nov 2020, 08:27 last edited by
                #9

                @jsulm like i said im just a newbie with programming. was hoping to find some help here. which incase guess i came to the wrong place. DHTread(self) is called. it just shows the value onto the UI through lcdnumber display

                J 1 Reply Last reply 2 Nov 2020, 08:31
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                • H helloworldddd
                  2 Nov 2020, 08:27

                  @jsulm like i said im just a newbie with programming. was hoping to find some help here. which incase guess i came to the wrong place. DHTread(self) is called. it just shows the value onto the UI through lcdnumber display

                  J Offline
                  J Offline
                  jsulm
                  Lifetime Qt Champion
                  wrote on 2 Nov 2020, 08:31 last edited by jsulm 11 Feb 2020, 08:34
                  #10

                  @helloworldddd said in DHT11 Sensor with RPI:

                  DHTread(self) is called

                  That is good. Now you can add the values to a list (myList.append(myValue)). But it is better to use https://www.oreilly.com/library/view/python-cookbook/0596001673/ch05s19.html in your case as you want to have a list with fixed max size and remove old values if you insert new values into full list.

                  https://forum.qt.io/topic/113070/qt-code-of-conduct

                  H 2 Replies Last reply 2 Nov 2020, 08:41
                  0
                  • J jsulm
                    2 Nov 2020, 08:31

                    @helloworldddd said in DHT11 Sensor with RPI:

                    DHTread(self) is called

                    That is good. Now you can add the values to a list (myList.append(myValue)). But it is better to use https://www.oreilly.com/library/view/python-cookbook/0596001673/ch05s19.html in your case as you want to have a list with fixed max size and remove old values if you insert new values into full list.

                    H Offline
                    H Offline
                    helloworldddd
                    wrote on 2 Nov 2020, 08:41 last edited by
                    #11

                    @jsulm ahhh u could have started with that but thanks so much for your help !

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                    • J jsulm
                      2 Nov 2020, 08:31

                      @helloworldddd said in DHT11 Sensor with RPI:

                      DHTread(self) is called

                      That is good. Now you can add the values to a list (myList.append(myValue)). But it is better to use https://www.oreilly.com/library/view/python-cookbook/0596001673/ch05s19.html in your case as you want to have a list with fixed max size and remove old values if you insert new values into full list.

                      H Offline
                      H Offline
                      helloworldddd
                      wrote on 3 Nov 2020, 06:01 last edited by
                      #12

                      @jsulm hello, sorry to bother u again. do u know how to use plot values to time, time as x axis on pyqtgraph? im using the command self.widget.plot() i would like to input the x axis value as time instead of a list of number like below. Thanks in advance !

                      hour = [1,2,3,4,5,6,7,8,9,10]
                      reading = []  #this is the reading from the sensor
                      
                      self.widget.plot(hour, reading)
                      
                      J 1 Reply Last reply 3 Nov 2020, 06:03
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                      • H helloworldddd
                        3 Nov 2020, 06:01

                        @jsulm hello, sorry to bother u again. do u know how to use plot values to time, time as x axis on pyqtgraph? im using the command self.widget.plot() i would like to input the x axis value as time instead of a list of number like below. Thanks in advance !

                        hour = [1,2,3,4,5,6,7,8,9,10]
                        reading = []  #this is the reading from the sensor
                        
                        self.widget.plot(hour, reading)
                        
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                        J Offline
                        jsulm
                        Lifetime Qt Champion
                        wrote on 3 Nov 2020, 06:03 last edited by
                        #13

                        @helloworldddd said in DHT11 Sensor with RPI:

                        do u know how to use plot values to time, time as x axis on pyqtgraph?

                        Sorry, I never used pyqtgraph. Did you check its documentation?

                        https://forum.qt.io/topic/113070/qt-code-of-conduct

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                        3 Nov 2020, 06:01

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