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Software => Software => Topic started by: TVXQ on July 28, 2010, 11:42:40 PM

Title: HELP!!! SRF08 reading using C#
Post by: TVXQ on July 28, 2010, 11:42:40 PM

Hello,

I have written a program in C# that can read the distance from an SRF08 ultrasonic sensor.

The SRF08 is connected to a USB-I2C module and communicates via rs232.

I have attached my code below. But i think there is some problem with the program, but im not sure.

Any help would be most appreciated.

Thanks


using System;
using System.Collections.Generic;
using System.Text;
using System.Threading;
using System.IO.Ports;

namespace ConsoleApplication1
{
    class Program
    {
        const byte I2C_CMD = 0x55;
        int n;
        byte device_addr = 0xe0;
        byte[] sbuf;

        private System.IO.Ports.SerialPort port;

        public void run()
        {
            n = 0;
            device_addr = 0xe0;
            sbuf = new byte[100];
            setupCommPort("COM4");

           sbuf[0] = I2C_CMD;         
           sbuf[1] = device_addr;
           sbuf[2] = 0x00;
           sbuf[3] = 0x01;
            port.Write(sbuf, 0, 4);
            port.Read(sbuf, 0, 1); 

   if(sbuf[0]<20) {
      Console.WriteLine("Found tool ver. {0}", sbuf[0]);
      
      sbuf[0] = I2C_CMD;         // send gain limit
      sbuf[1] = device_addr;
      sbuf[2] = 0x01;
      sbuf[3] = 0x01;
      sbuf[4] = 20;
        port.Write(sbuf, 0, 5);
        port.Read(sbuf, 0, 1);

      sbuf[0] = I2C_CMD;         // send sonar rangeing (uS) command
      sbuf[1] = device_addr;
      sbuf[2] = 0x00;
      sbuf[3] = 0x01;
      sbuf[4] = 0x52;
        port.Write(sbuf, 0, 5);
        port.Read(sbuf, 0, 1);
      
      while(true) {
         
         Thread.Sleep(100);

         sbuf[0] = I2C_CMD;         // send sonar read command
         sbuf[1] = device_addr;
         sbuf[2] = 0x00;
         sbuf[3] = 0x04;
            port.Write(sbuf, 0, 4);
            port.Read(sbuf, 0, 4);
         //Console::WriteLine(L"Prectena verze {0}", sbuf[0]);   
         //Console::WriteLine(L"Prectene svetlo {0}", sbuf[1]);   

            Console.Write(sbuf[2]);
            Console.Write(" ");
            Console.Write(sbuf[3]);
            Console.WriteLine();


         //Console.WriteLine("Prectene {0} {1}", sbuf[2], sbuf[3]);
         //n = sbuf[2]<<8;
         //n |= sbuf[3];

         //Console::WriteLine(L"Prectene uS {0}",n);
         //Console.WriteLine("Prectene cm {0}", n/58);
         //Console::WriteLine(L"Prectene inche {0}", n/148);


         sbuf[0] = I2C_CMD;         // send gain limit
         sbuf[1] = device_addr;
         sbuf[2] = 0x01;
         sbuf[3] = 0x01;
         sbuf[4] = 0x14;
            port.Write(sbuf, 0, 5);
            port.Read(sbuf, 0, 1);

         sbuf[0] = I2C_CMD;         // send sonar rangeing (uS) command
         sbuf[1] = device_addr;
         sbuf[2] = 0x00;
         sbuf[3] = 0x01;
         sbuf[4] = 0x52;
            port.Write(sbuf, 0, 5);
            port.Read(sbuf, 0, 1);

      }
   } else {
      Console.WriteLine("Tool not found");
   }

        }

        static void Main(string[] args)
        {

            Program prog = new Program();
            prog.run();

        }

        private void setupCommPort(String comport)
        {
            port = new SerialPort();
            this.port.BaudRate = 19200;
            this.port.Parity = Parity.None;
            this.port.StopBits = StopBits.One;
            this.port.Handshake = Handshake.None;
            this.port.RtsEnable = false;
            this.port.ReadTimeout = 5000;
            this.port.WriteTimeout = 5000;
            port.PortName = comport;
            port.Open();

            if (port.IsOpen)
            {
                Console.WriteLine("Com Port 4 setup");
            }
        }

    }
}

Title: Re: HELP!!! SRF08 reading using C#
Post by: paulstreats on July 29, 2010, 03:13:42 AM

Hi,


 I have an SRF08 This is the command sequences that I used.

SEND RANGEING COMMAND

0xE0 - device address
0x00 - access register
0x01 - starts rangeing(cm)

READ SONAR

0xE0 - device address
0x02 - write the address of the distance register
0xE1 - write the address of the device with the READ bit set
the sonar should now send the data back

(remember that when you want to read the sonars distamce register, access it in write mode 0xE0 select the distance register then write the address of the sonar again with the read bit set 0xE1)