saleh jaffal / sensor

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Fork of SRF02 by Craig Evans

Files at this revision

API Documentation at this revision

Revision 3:d571cee468e9, committed 2015-05-08

Comitter:
sjaffal3
Date:
Fri May 08 15:41:19 2015 +0000
Parent:
2:284c0564fc75
Commit message:
before beep

Changed in this revision

SRF02.cpp Show annotated file Show diff for this revision Revisions of this file
SRF02.h Show annotated file Show diff for this revision Revisions of this file 
--- a/SRF02.cpp	Thu Apr 30 10:34:19 2015 +0000
+++ b/SRF02.cpp	Fri May 08 15:41:19 2015 +0000
@@ -53,8 +53,8 @@
         wait(0.1);    
     }    
 }
-/*
-int SRF02::getDistanceIN()
+
+int SRF02::getDistanceIn()
 {
     char data[2];
     
@@ -81,6 +81,34 @@
 
     // high byte is first, then low byte, so combine into 16-bit value
     return (data[0] << 8) | data[1];
-}*/
+}
 
+int SRF02::getDistanceUs()
+{
+    char data[2];
+    
+    // need to send CM command to command register
+    data[0] = CMD_REG;
+    data[1] = US_CMD;
+    int ack = i2c->write(SRF02_W_ADD,data,2);  
+    if (ack)
+        error();  // if we don't receive acknowledgement, flash error message
+        
+    // this will start the sensor ranging, the datasheet suggests a delay of at least 65 ms before reading the result
+    wait_ms(70);
+    
+    // we can now read the result - tell the sensor we want the high byte
+    char reg = RANGE_H_REG;   
+    ack = i2c->write(SRF02_W_ADD,&reg,1);  
+    if (ack)
+        error();  // if we don't receive acknowledgement, flash error message
+    
+    // if we read two bytes, the register is automatically incremented (H and L)
+    ack = i2c->read(SRF02_R_ADD,data,2); 
+    if (ack)
+        error();  // if we don't receive acknowledgement, flash error message
 
+    // high byte is first, then low byte, so combine into 16-bit value
+    return (data[0] << 8) | data[1];
+}
+

--- a/SRF02.h	Thu Apr 30 10:34:19 2015 +0000
+++ b/SRF02.h	Fri May 08 15:41:19 2015 +0000
@@ -71,6 +71,8 @@
     * 
     */
     int getDistanceCm();
+    int getDistanceIn();
+    int getDistanceUs();
 
 private:
     /** Hangs in infinite loop flashing 'blue lights of death'