Diff: SRF02.cpp

Revision:

2:bb52fa779a57

Parent:

0:b729d2ce03bd

--- a/SRF02.cpp	Sun Mar 08 14:21:40 2015 +0000
+++ b/SRF02.cpp	Thu May 05 11:48:40 2016 +0000
@@ -43,7 +43,35 @@
     // high byte is first, then low byte, so combine into 16-bit value
     return (data[0] << 8) | data[1];
 }
-
+int SRF02::getDistanceIn()
+{
+    char data[2];
+    
+    // need to send CM command to command register
+    data[0] = CMD_REG;
+    data[1] = INCH_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];
+}
+ 
 void SRF02::error()
 {
     while(1) {