查看“Resistance meter”的源代码

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==Objective==

The course will show you how to use Processing software to display the value of the resistance meter in the form of the graph, and the resistance meter can be achieved by Microduino.

==Equipment==
*'''[[Microduino-Core]]'''
*'''[[Microduino-FT232R]]'''

*Other Hardware Equipment 
**A USB cable 
**A 20k Ω resistor 
**A 104 ceramic capacitor 
**A bread board 
**A box of jumpers 



==Schematic Diagram==


[[File:ResistanceMeterSchematics.jpg|600px|center|thumb]]


==Program==

Referring to  ResistanceMeter

processingResistanceMeter

==Debugging==

Step 1：Building hardware environment according to the schematic diagram, just as follows: 
[[File:IResistanceMeterConnectionDiagram.jpg|600px|center|thumb]]


Step 2：Here is the code we need：

The code of two ends (Processing and Microduino) 

Microduino:

//Using filter algorithm to calculate resistance and displaying the data on Processing via serial output.   

  //filter Algorithm
  float filter()
  {
    float sum = 0;
    for(int count = 0; count < N; count++)
    {
      sum += r;
      delay(5);
    }
    return (float)(sum / N);
  }

Processing:

//After getting the data of the first serial port, you can define or cache the data if there is a new line. 

 // is always my Microduino, so I open Serial.list()[0].
 // Open whatever port is the one you're using.
 myPort = new Serial(this, Serial.list()[0], 9600);
 myPort.bufferUntil('\n'); // Trigger a SerialEvent on new line

//On the screeen, displaying the data received from Microduino in the form of graph and marking scale. 

  String val = myPort.readStringUntil('\n');
  if (val != null) {
    if ("Infinity!!".equals(val)) {
      unit="resistancetoo big";
    } 
    else {
      if ("K ohm".equals(val)) {
        unit="K ohm";
      }
      else if (" ohm".equals(val)) {
        unit=" ohm";
      }
      else {
        val = trim(val);
        println(val);
        resistance=Float.parseFloat(val);
      }
    }
  }
  vals[vals.length-1] = 200-resistance;
  //Display scale
  text ( "200-", 370, 10); 
  text ( "--", 370, 50); 
  text ( "100-", 370, 100);
  text ( "--", 370, 150); 
  text ( "0-", 370, 200); 
  //show current num
  text ( resistance+unit, 0, 10);

Step 3：Uploading the code and compiling it successfully. 

Step 4： Putting the resistor ready to measure between the yellow and the black lines on the graph, watching resistance on Processing. 

==Result==

The graph will display the current resistance.    
[[File:IResistanceMeterResult.jpg|600px|center|thumb]]


==Video==