ASP.NET C# web application problem

[cuky3]

Hello all,
I have the following setup: Master Brick, Accelerometer 2.0, Ethernet Master Extension and the RED brick.

For my project I am developing a web application for accelerometer data acquisition using Visual Studio ASP.NET Web Forms written in C#. I have successfully configured local area network, added TinkerForge C# bindings and my basic console app example works very well. However when I code in a Web Form my code doesn't get executed.

My web app consists of two drop down menus where you can choose frequency (ID="DropDownList2") and data rate (ID="DropDownList1") as well as input (ID="Time") in which user specifies duration of an acquisition. After the defined time x values needs to be printed in the text area (ID="textAr"). To start the acquisition a button Start is pressed which executes a method in code behind. To control time an AJAX timer and ScriptManager is used. All items are in html <form/> tag and runat server. My code behind looks like this:

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Dynamic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using Tinkerforge;

namespace Prikupljanje_podataka
{
    public partial class WebForm1 : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {

        }

        const string HOST = "192.168.150.3";
        const int PORT = 8080;
        const string UID = "Jej";
        public IPConnection ipcon = new IPConnection();
        public List<short> xos = new List<short>();
        public List<short> yos = new List<short>();
        public List<short> zos = new List<short>();

        public void Start_Click(object sender, EventArgs e)
        {
            Prikupljanje();
            int t1 = Convert.ToInt32(Time.Value);
            int t2 = t1 * 1000;
            Timer1.Enabled = true;
            Timer1.Interval = t2;
        }
        
        public void Prikupljanje()
        {
            byte fr = Convert.ToByte(DropDownList2.SelectedValue);
            byte rn = Convert.ToByte(DropDownList1.SelectedValue);
            ipcon.Connect(HOST, PORT);
            BrickletAccelerometerV2 a = new BrickletAccelerometerV2(UID, ipcon);
            a.SetConfiguration(fr, rn);
            a.GetConfiguration(out byte dataRate, out byte fullScale);
            System.Diagnostics.Debug.WriteLine(Convert.ToString(dataRate));
            System.Diagnostics.Debug.WriteLine(Convert.ToString(fullScale));
            a.SetContinuousAccelerationConfiguration(true, true, true, Convert.ToByte(1));
            a.ContinuousAcceleration16BitCallback += AccelerationCB;
            ipcon.Disconnect();
            

        }

        public void AccelerationCB(BrickletAccelerometerV2 sender, short[] acceleration)
        {
            short[] akc = acceleration;
            short[] x = { akc[0], akc[3], akc[6], akc[9], akc[12], akc[15], akc[18], akc[21], akc[24], akc[27] };
            short[] y = { akc[1], akc[4], akc[7], akc[10], akc[13], akc[16], akc[19], akc[22], akc[25], akc[28] };
            short[] z = { akc[2], akc[5], akc[8], akc[11], akc[14], akc[17], akc[20], akc[23], akc[26], akc[29] };
            Debug.WriteLine(string.Join(",", x));
            Debug.WriteLine("test");
            xos.AddRange(x);
            yos.AddRange(y);
            yos.AddRange(z);

        }

        public void Timer1_Tick(object sender, EventArgs e)
        {
            
            Timer1.Enabled = false;
            textAr.Value += "Timer works";
            textAr.Value += string.Join(",", xos);
            Debug.WriteLine("test2");
          
        }
        
    }
    
}

The weird thing is that System.Diagnostics.Debug.WriteLine(Convert.ToString(dataRate)); and
System.Diagnostics.Debug.WriteLine(Convert.ToString(fullScale)); return the value of user defined frequency and data range, but Debug.WriteLine(string.Join(",", x)); and Debug.WriteLine("test") in void AccelerationCB don't return anything which means that public void AccelerationCB(BrickletAccelerometerV2 sender, short[] acceleration){} doesn't get executed. The last Debug line "Debug.WriteLine("test2");" is returning a string "test2" after user defined time.

My question is, am I doing something wrong with the acceleration callback, is a.ContinuousAcceleration16BitCallback += AccelerationCB; correctly written and assigned, does my code look wrong? When I run the App using ISS Explorer there are no errors or exceptions, on a button click the timer starts but nothing happens after user defined time, only "Timer works" is printed in the textarea.

Sorry for the long post I can't wrap my head around this, if needed I can provide code from a C# console app or the front end html. Thanks in advance!

[rtrbt]

Hi,

After registering the callback, you are calling ipcon.Disconnect(), but if you disconnect from the Ethernet Extension, no callbacks can be delivered. Removing this line should fix your problem.

Closing the connection is still a good idea, but I think you do this (i.e. call ipcon.Disconnect()) in the Timer1_Tick handler.

[cuky3]

Hi, thank you for your answer.

It solved the problem partially, when I add ipcon.Disconnect() to the Timer1_Tick I get the following exception:

And if I remove ipcon.Disconnect() completely the values in Debug.WriteLine(string.Join(",", x)); just keep on coming and my text area is still empty.

Do you have any further suggestions?

[rtrbt]

This is strange: This exception is only thrown if your IPConnection was not connected. However I don't see how you can reach the Timer1_Tick without first calling connect in your "Prikupljanje" function.

1 hour ago, cuky3 said:

And if I remove ipcon.Disconnect() completely the values in Debug.WriteLine(string.Join(",", x)); just keep on coming and my text area is still empty.

This is because if you never call .Disconnect(), you will still receive callbacks.

If you use the following implementation of Timer1_Tick

public void Timer1_Tick(object sender, EventArgs e)
{
  Timer1.Enabled = false;
  Debug.WriteLine("Timer1_Tick");
}

Do you get the "Timer1_Tick" output only once? If not, your single-shot logic does not work.

 

Some other things: You should switch the order of the following lines:

Timer1.Enabled = true;
Timer1.Interval = t2;

If you enable the Timer before setting the interval, it is possible, that the timer runs with the wrong pre-configured interval first.

A similar problem is with these lines:

a.SetContinuousAccelerationConfiguration(true, true, true, Convert.ToByte(1));
a.ContinuousAcceleration16BitCallback += AccelerationCB;

If you first register the callback and then call the Set...Configuration function to enable the callback, you don't miss any callback packets.

[cuky3]

The timer works ok and displays only 1 tick in the debug. I have tried removing the timer completely and adding new button which will disconnect IP connection but I get the same exception. The ipcon.Disconnect(); only works if it is in public void Prikupljanje() or public void AccelerationCB(BrickletAccelerometerV2 sender, short[] acceleration), outside of these two methods I always get NotConnectedException. It seems like there is no communication between these two voids and other voids.

[rtrbt]

22 hours ago, cuky3 said:

The ipcon.Disconnect(); only works if it is in public void Prikupljanje() or public void AccelerationCB(BrickletAccelerometerV2 sender, short[] acceleration), outside of these two methods I always get NotConnectedException.

This is really strange. To find out when the IPConnection is disconnected, you can use the DisconnectedCallback, for example like this:

static void DisconnectedCB(IPConnection sender, short disconnectReason) {
	Debug.WriteLine(string.format("Disconnected at {}; reason: {}", DateTime.Now, disconnectReason));
}

Then register the callback with

ipcon.DisconnectedCallback += DisconnectedCB;

in the Start_Click function.

If you also add similar debug logging to the other functions, you should be able to see when the disconnect happens.