Difference between revisions of "Atmospheric pressure data collection"

Objective

This tutorial will use the BM180 air pressure sensor on Microduino-10DOF module and the data will display in Processing.

Equipment

• Microduino-Core
• Microduino-FT232R

Microduino-10DOF

• Other equipment
  • USB cable one

Schematic

Use the Microduino-10DOF module's BMP180 sensor directly.

Program

Refers to AtmosphericDataCollection

processingBMP180

Debug

Step 1: Set up hardware system, as follows:

Step 2: Explain the code:

This example needs two parts code, one is Processing and the other is Microduino.

Microduino:

//Get the air pressure data for Processing's display.

 void vobmp085()
 {
   // request pressure (3x oversampling mode, high detail, 23.5ms delay)
   barometer.setControl(BMP085_MODE_PRESSURE_3);
   while (micros() - lastMicros < barometer.getMeasureDelayMicroseconds());
   // read calibrated pressure value in Pascals (Pa)
   pressure = barometer.getPressure();
   Serial.println(pressure/1000,3);
   delay(100);
 }

Processing:

//Get the first seria data

 // 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

//Display the data that Microduino received in screen and mark the table scale.

 void draw() {
   background(255);
   // Draw lines connecting all points
   for (int i = 0; i < vals.length-1; i++) {
     stroke(0);
     strokeWeight(1);
     line(i, vals[i], i+1, vals[i+1]);
   }
   // Slide everything down in the array
   for (int i = 0; i < vals.length-1; i++) {
     vals[i] = vals[i+1];
   }
   String val = myPort.readStringUntil('\n');
   if (val != null) {
     val = trim(val);
     println(val);
     pressure=Float.parseFloat(val);
   }
   vals[vals.length-1] = 200-pressure;
   //Display scale
   text ( "200-", 370, 10); 
   text ( "--", 370, 50); 
   text ( "100-", 370, 100);
   text ( "--", 370, 150); 
   text ( "0-", 370, 200); 
   //show current num
   text ( pressure+" Kpa", 0, 10);
 }

Step 3: Compile the code and download it.

Step 4: After running, observe the curve on Processing.

Result

Screen will display the air pressure data curve, as follows：

Video