inxtremo

Any thoughts of concerns about going this route?

Hey, i have the similar devices running here. No problems so far. They move a mechanical pant/tilt device with a camera connected. The power of the stepper are ok for that.

Greetings,
Daniel

Hi, great projects in this thread. Wish my own cnc in the future. One simple and fast question, Has anyone implemented acceleration and deceleration for the stepper motors. Tried it myself but it not really works great. Thanks a lot, Daniel

A little off topic but...

the following line of code was posted in the example...

string line = System.Text.Encoding.UTF8.GetString(bytes);

This method does not exist under NMF 4.2. Did they pull it?

Hey,

as far as i know the GetString method does not exist in .NET MF. Try instead the GetChars method.

The sample you seen does not run on the Netduino. It is a class who sends the message to the Netduino. The class works with the full .NET 4 Framework.

Here is a code example how i do it.

private static void serial_DataReceived(object sender, SerialDataReceivedEventArgs e)
        {
            // wait a bit for filling the buffer
            System.Threading.Thread.Sleep(100);

            // message string
            string msg = null;

            // allocate a byte array
            byte[] bytes = new byte[_serial.BytesToRead];

            // read bytes
            _serial.Read(bytes, 0, bytes.Length);

            // send bytes back for error checking
            _serial.Write(bytes, 0, bytes.Length);

            // encode bytes to a string message 
            msg = new string(System.Text.Encoding.UTF8.GetChars(bytes));

            // split message
            if (msg != null)
            {
                // split parameter
                splittedMsg = msg.Split(',');

                // allocate array for the parameters
                int[] param = new int[splittedMsg.Length];

                // write parameter to the array
                for (int i = 0; i < splittedMsg.Length; i++)
                {
                    param[i] = System.Int32.Parse(splittedMsg[i]);
                }

                // do something
                switch (param[0])
                {
                    case 0:
                       blaaa ....
                       break;
                    default:
                        break;
                }
            }
        }

Best regards,
Daniel

Hay, i think i have the soultion. Changing the voltage from my power supply from 12V to 5V makes it moves fine. I don´t know why but i´m happy that it works now. Thanks or the great help. Best regards, Daniel

Forgive the obvious. That power supply was delivered to you pre-assembled. You tested it after you built it right? You got a cordless drill battery laying around?

Both, the power supply and the "breadboard power supply" were pre-assembled. I tested the breadboard power supply a few weeks ago but there nothing worked.

Option 1:
I power both drivers with the "breadboard power supply" (5V) and drive two steppers with each 12V and 330mA. The external power supply is 12V and 1500mA. --> Both steppers moves but not really well. I think the 5V is too less.


Option 2:
I power both drivers with the "breadboard power supply" (5V) and drive two steppers with each 4V and 1200mA. The external power supply is 12V and 2500mA. --> Both steppers moves but not really well but better as with the 1500mA power supply.

Option 3:
I power both drivers with the "breadboard power supply" (5V) and drive two steppers with each 12V and 330mA. The external power supply is 12V and 1500mA. --> Both steppers stands still.

Option 4:
I power both drivers with the "breadboard power supply" (5V) and drive two steppers with each 4V and 1200mA. The external power supply is 12V and 2500mA. --> Both steppers stands still. But it seems they try to move.

Directly connection the external power supply bring no movement at all.

And suggestion. Maybe i have the wrong power supply? But i tried three different types now. the last from my ole notebook with 18,5V and 3,5A.

Update:

Try to connect an ATX-Power supply from an old PC. 12V max 30A. One driver moves a little bit.

Interestingly the steppers moves at the beginning of the test. Later there is often no more movement like in the beginning (10sec later or so). It seems like there is a rechargable becoming empty

Thanks