Manual
Copyright © Dr Robot Inc. 2008  
10
Return Value  Distance to Object 
<=585  80 cm or longer 
585 to 3446  80 to 8 cm 
>=3446  0 to 8 cm 
Remarks: 
The relationship between the return data and the distance is not linear. Please refer to the 
sensor’s datasheet for distance-voltage curve. The data returned is the raw data of the 
analog to digital converter. The output voltage of the sensor can be calculated from the 
following equation: 
Sensor output voltage = (ival) * 3.0 / 4095 (V) 
(e.g. Sharp GP2Y0A21YK 
“http://sharp-world.com/products/device/lineup/data/pdf/datasheet/gp2y0a_d_e.pdf”) 
III.1.3.  Human Sensors 
25  short GetSensorHumanAlarm1 (); 
26  short GetSensorHumanAlarm2 (); 
Description: 
GetSensorHumanAlarm returns the current human alarm data from DHM5150 Human 
Motion Sensor Module. Please refer to the DHM5150 hardware manual for detailed 
information. 
Syntax:  ival = GetSensorHumanAlarm1();    //1
st
 human alarm 
    ival = GetSensorHumanAlarm2 ();  // 2
nd
 human alarm 
Parameter:    void 
Return value:    short  ival; 
Return data interpretation: 
The return data is the raw value of the analog to digital converter indicating the amplified (x 
5 times) output voltage of the sensor device. The data range is between 0 and 4095. When 
there is no human present, the module output voltage is about 1.5 V and return value is 
about 2047. 
Remarks: 
To detect human presence, the application should compare the difference of two samples 
(to detect the change from “absence” to “presence”), and also compare the sample data to a 
user defined threshold (to determine whether to report an alarm or not). The threshold 
determines the sensitivity of sensor. The higher the threshold is the lower the sensitivity 
will be. 










