Diff: main.cpp

Revision:

0:963c0badad70

Child:

1:c7a36fa2c772

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Wed Sep 27 06:51:22 2017 +0000
@@ -0,0 +1,42 @@
+#include "mbed.h"
+#include "SoftSerial.h"
+
+SoftSerial softSerial(dp18,dp17); //Tx,Rx
+Serial pc(USBTX, USBRX); //Tx,Rx
+
+int main() {
+    
+    softSerial.baud(9600);  //to mbed cat
+    pc.baud(9600);  // to mh-z19 CO2 sensor
+    
+    char command[] = { 0xff , 0x01 , 0x86 , 0 , 0 , 0 , 0 , 0 , 0x79 }; //command of Read CO2 concentration
+    char responds[9];
+    
+    unsigned char c;
+    
+    if( pc.readable() ) // throw received data away
+        responds[0] = pc.getc(  );
+    
+    while(1) {
+        
+        //send command
+        for( int i=0 ; i<9 ; i++ ) {
+            while( pc.writeable() == 0 );
+            pc.putc( command[i] );
+        }
+        
+        //receve responds
+        c=0;    //calc check sum
+        softSerial.printf(" responds:");
+        for( int i=0 ; i<9 ; i++ ) {
+            responds[i] = pc.getc(  );
+            softSerial.printf("%x ",responds[i]);
+            c += responds[i];
+        }
+        c -= responds[8];
+        c = ( 0xff - c );
+        softSerial.printf(" csm:%x CO2:%dppm temp:%dC stat:%d\r" , c , responds[2]*256 + responds[3] , responds[4]-40 , responds[5]);
+        wait(1);
+
+    }
+}