(((MiWSN)))
Mi Wireless Sensor Network
Self-Monitoring Wireless Sensor Network Solutions

Application Notes

 

Application Note - Monitoring Room Temperature
The sensor is configured with a “Sensor Name”, “Report Period”, “Temp High Alarm”, and “Temp Low Alarm”. The sensor is attached to a surface in the area that the air temperature is going to be monitored, using the double-sided adhesive tape provided.

 

Application Note - Monitoring Door Movement
The sensor is configured with a “Sensor Name” and the “Motion Alarm” field is set to “Yes”. The “Motion Threshold” field should be set to a value between 1 and 20. A value of 1 will make the sensor very sensitive to door motion, and will even alarm if there is a knock on the door. The user may experiment with different “Motion Threshold” field values to find one that best suits their application. The sensor is attached to the back of the door to be monitored, using the double-sided adhesive tape provided.

 

Application Note - Monitoring Object Shock
The sensor is configured with a “Sensor Name” and the “Motion Alarm” field is set to “Yes”. The “Motion Threshold” field should be set to a value above 20. The user may experiment with different “Motion Threshold” values to find one that best suits their application. The sensor is attached to the back of the object to be monitored, using the double-sided adhesive tape provided.

 

Application Note - Monitoring Sump Pit
The sensor is configured with a “Sensor Name” and set port function to “Alarm Close/Wet”.  One end of the sensing wire is attached to the sensor and the other end is placed in a location where the ends will get wet when the water level rises too high. The sensor should be placed outside the well so that it will not get wet. The sensing wires are attached to the well sides using the double-sided adhesive tape provided.

 

Application Note - Monitoring Water Leakage
The sensor is configured with a “Sensor Name” and set port function to “Alarm Close/Wet”. One end of the sensing wire is attached to the sensor and the other end is placed in a location where the ends will get wet when water leaks and accumulates. The sensor should be placed in a location where it would not get wet. The sensing wires are held in place using the double-sided adhesive tape provided.

 

Application Note - Monitoring Holding Tank for Low Level
The sensor is configured with a “Sensor Name” and set port function to “Alarm Open/Dry”. One end of the sensing wire is attached to the sensor and the other end is placed in the liquid to be monitored. When the liquid is no longer in contact with the ends of the sensing wire, an alarm will be sent. The sensor should be placed in a location where it would not get wet. The sensing wires are held in place using the double-sided adhesive tape provided.

 

Application Note - Monitoring Door Open or Closed
The sensor is configured with a “Sensor Name” and set port function to “Alarm Close/Wet” or “Alarm Open/Dry” depending when you wish to get the alarm condition. One end of the sensing wire is attached to the sensor and the other ends are attached to a user supplied dry contact magnetic reed switch or a switch. These types of switches are readily available from your local hardware or electronics store. The sensing wires and sensor are held in place using the double-sided adhesive tape provided.

 

Application Note - Monitoring Light Levels
The sensor is configured with a “Sensor Name” and set port function to “Light (dlx)”. A PDV-P9203 resistive light sensor element is inserted into the sensor port. Light levels are reported in tenths of a LUX, with a range of 0 (being the darkest) and 6000 (being bright sun light). You can set alarm conditions by setting the “Port High Alarm” and “Port Low Alarm” fields. Leaving these fields black will disable the alarm condition.


Application Note - Monitoring Humidity Levels
The sensor is configured with a “Sensor Name” and set port function to “Humidity (RH)”. An HCH-1000-002 capacitive humidity sensor element is inserted into the sensor port. Relative humidity levels are reported between 0 (dry) and 100 (wet). You can set alarm conditions by setting the “Port High Alarm” and “Port Low Alarm” fields. Leaving these fields black will disable the alarm condition. Once a sensor is configured it may need to be calibrated. Calibration is done by placing the sensor in a saturated sodium salt chamber for 15 minutes and then pressing and holding the sensor test button for 10 seconds. The RH humidity reading should now be 75%. A simple saturated sodium salt chamber can be made by mixing 6 tablespoons of salt with 12 tablespoons of water in a small bowel and placing it in a sealed baggie with the sensor.


Application Note - Monitoring AC Voltage
The sensor is configured with a “Sensor Name” and set port function to “mVAC 0.3V Max”. An AC voltage between 0 and 300mVAC is applied to the port bins and RMS voltage is reported in milli-volts. You can set alarm conditions by setting the “Port High Alarm” and “Port Low Alarm” fields. Leaving these fields black will disable the alarm condition. A resistor voltage divider on the input can be used to scale higher voltages to within the range accepted by the sensor.


Application Note - Monitoring DC Voltage
The sensor is configured with a “Sensor Name” and set port function to “mVDC 1.0V Max”. A DC voltage between 0 and 1000mVDC is applied to the port bins and voltage is reported in milli-volts. The port input pin second from the edge is ground. You can set alarm conditions by setting the “Port High Alarm” and “Port Low Alarm” fields. Leaving these fields black will disable the alarm condition. A resistor voltage divider on the input can be used to scale higher voltages to within the range accepted by the sensor.


Application Note - Monitoring Capacitance
The sensor is configured with a “Sensor Name” and set port function to “CapSen (cs)”. The sensor will measure the capacitance between the two wires connected to the port input pins and return a relative count number. The port input pin second from the edge is ground. You can set alarm conditions by setting the “Port High Alarm” and “Port Low Alarm” fields. Leaving these fields black will disable the alarm condition. Connecting pins to small metal surfaces separated by an insulator can make a touch panel.


Application Note - Monitoring Amp Hours and Power usage
The sensor is configured with a “Sensor Name” and set port function to “mVh 0.3V Max”. The sensor will integrate and accumulate milli-volt hours for the AC signal applied to the port pins. You can set alarm conditions by setting the “Port High Alarm” and “Port Low Alarm” fields. Leaving these fields black will disable the alarm condition. When a current transformer with a load resistor is connected to the port pins, current over time can be monitored. A typical Current Transformer is the Mi-Current-1 supplied by MiWSN. This transformer has a rating of 100A=333mVAC. One can calculate Amp Hours with the Mi-Current-1 using Ah=mVh*0.3. One can calculate Killowatt hours (like that of you home power meter) with the Mi-Current-1 using KWH=mVh*0.3*120/1000. Note the 120 is an approximation of your line voltage.

Application Note - Optimum Mi-Sensor-1 Placement
The sensor’s internal antenna is partially directional. This means that it will perform better when oriented in the direction of the gateway. Maximum sensor performance will be obtained when the sensor sensing port is at the bottom and the large flat surface is facing the gateway.

 

Application Note - Optimum Mi-Gateway-1 Placement
The gateway’s internal antenna is partially directional. This means that it will perform better when oriented in the direction of the sensor. Maximum gateway performance will be obtained when the gateway LAN and power cable are at the bottom and the large flat surface is facing the sensor.