IISEC
Description: controlling the DC motor speed based on the temperature get from LM35 sensor.
Dependencies: mbed
Revision 0:7243db10fb59, committed 2018-04-02
- Comitter:
- Victordang
- Date:
- Mon Apr 02 05:46:58 2018 +0000
- Commit message:
- LM35 and DC Motor
Changed in this revision
| main.cpp | Show annotated file Show diff for this revision Revisions of this file |
| mbed.bld | Show annotated file Show diff for this revision Revisions of this file |
diff -r 000000000000 -r 7243db10fb59 main.cpp
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp Mon Apr 02 05:46:58 2018 +0000
@@ -0,0 +1,70 @@
+#include "mbed.h"
+#include "string"
+
+PwmOut motor(p21);
+DigitalOut myled(LED1);
+Serial pc(USBTX, USBRX); //enable serial port which links to USB
+AnalogIn sensor(p15); //LM35 sensor
+float current_pulse = 0;
+float offset = 0;
+Ticker in;
+void motor_speed(float offset)
+{
+ //current_pulse += offset;
+ motor = offset;
+}
+float getTemperature(){
+ int i,N=400;
+ float tempC, avg, a[N];
+ myled = 1;
+ avg = 0;
+
+ for(i=0;i<N;i++)
+ {
+ a[i]=sensor.read();
+
+ wait(.01);
+ }
+ for(i=0;i<N;i++)
+ {
+
+ avg=avg+(a[i]/10*1000);
+
+ }
+ tempC = (avg/N*10);
+ pc.printf("\n\rTemperature is %4.1f C, avg = %4.5f \r\n",tempC, avg/N);
+
+ return tempC;
+}
+int main() {
+
+ motor.period(0.01);
+ motor = 0;
+ float tempC, threshold = 15;
+ string err_str;
+ pc.printf("\r\nLM35 Temperature Program");
+ pc.printf("\r\n******************\r\n");
+ wait(1); // wait 1 second for device stable status
+ while (1) {
+
+ tempC = getTemperature();
+
+
+ if(tempC >= threshold)
+ {
+ offset = tempC - threshold + 0.5;
+ motor_speed(offset);
+ }
+ else
+ {
+ offset = 0;
+ motor_speed(offset);
+ }
+ pc.printf("\n\r pulse width %f, offest = %f \r\n",motor.read(), offset);
+
+ myled = 0;
+ wait(1);
+ }
+
+}
+
diff -r 000000000000 -r 7243db10fb59 mbed.bld --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mbed.bld Mon Apr 02 05:46:58 2018 +0000 @@ -0,0 +1,1 @@ +http://mbed.org/users/mbed_official/code/mbed/builds/994bdf8177cb \ No newline at end of file