1128 User Guide

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Getting Started

Checking the Contents

You should have received: A sonar sensor A sensor cable		In order to test your new Phidget you will also need: A PhidgetInterfaceKit 8/8/8 or a PhidgetTextLCD A USB cable A soldering iron and solder A piece of wire (optional)

Soldering the Sensor Cable

Solder one end of the sensor cable to the Sonar Sensor. The black wire is soldered to GND, the red wire to +5 and the white wire to AN. Optionally a fourth wire can be soldered to RX in order to turn the sensor on and off from your computer.

Connecting the Pieces

Connect the Sonar Sensor to the Analog Input 7 on the PhidgetInterfaceKit 8/8/8 using the sensor cable. If you are using the 4th wire connect it to a digital output port. Connect the PhidgetInterfaceKit to your PC using the USB cable.

Testing Using Windows 2000 / XP / Vista / 7

Make sure you have the current version of the Phidget library installed on your PC. If you don't, follow these steps:

1. Go to the Quick Downloads section on the Windows page
2. Download and run the Phidget21 Installer (32-bit, or 64-bit, depending on your system)
3. You should see the icon on the right hand corner of the Task Bar.

Running Phidgets Sample Program

Double clicking on the icon loads the Phidget Control Panel; we will use this program to ensure that your new Phidget works properly.

The source code for the InterfaceKit-full sample program can be found in the quick downloads section on the C# Language Page. If you'd like to see examples in other languages, you can visit our Languages page.

Updating Device Firmware

If an entry in this list is red, it means the firmware for that device is out of date. Double click on the entry to be given the option of updating the firmware. If you choose not to update the firmware, you can still run the example for that device after refusing.

Double Click on the icon to activate the Phidget Control Panel and make sure that the Phidget InterfaceKit 8/8/8 is properly attached to your PC.

If you are using a 3-wire connection 1. Double Click on Phidget InterfaceKit 8/8/8 in the Phidget Control Panel to bring up InterfaceKit-full and check that the box labelled Attached contains the word True. 2. Make sure that the Ratiometric box is Ticked. 3. Move the Sonar Sensor around and point at different objects. The distance is given in the Analog In box. 4. You can adjust the input sensitivity by moving the slider pointer. 5. Click on the Sensors button to bring up the Advanced Sensor Form.
If you are using a 4-wire connection Double Click on Phidget InterfaceKit 8/8/8 in the Phidget Control Panel to bring up InterfaceKit-full and check that the box labelled Attached contains the word True. Make sure that the Ratiometric box is Ticked. Activate the Sonar Sensor, by clicking in the Digital Out box. A tick mark will appear and the Sonar Sensor is on. To turn the sensor off, click on the Digital box again. The tick mark disappears and the sensor is off. The bottom row shows the status of the request, while the top row displays the status of the digital output as reported by the 1128. Move the Sonar Sensor around and point at different objects. The distance is given in the Analog In box. You can adjust the input sensitivity by moving the slider pointer. Click on the Sensors button to bring up the Advanced Sensor Form.
In the Sensor 7 box, select the 1116 - Sonar Sensor from the drop down menu. The distance of the object from the sensor is shown here. Formula used to convert the analog input SensorValue into distance.

Testing Using Mac OS X

1. Go to the Quick Downloads section on the Mac OS X page
2. Download and run the Phidget OS X Installer
3. Click on System Preferences >> Phidgets (under Other) to activate the Preference Pane
4. Make sure that the is properly attached.
5. Double Click on in the Phidget Preference Pane to bring up the Sample program. This program will function in a similar way as the Windows version.

Using Linux

For a step-by-step guide on getting Phidgets running on Linux, check the Linux page.

Using Windows Mobile / CE 5.0 / CE 6.0

For a step-by-step guide on getting Phidgets running on Windows CE, check the Windows CE page.

Technical Details

The Sonar Sensor is manufactured by Maxbotix.com. We have added a sensor cable and instructions on soldering the cable to the sensor. The Sonar Sensor is Ratiometric. Make sure that the ratiometric property is set to TRUE when programming the sensor. Each time after the LV-MaxSonar®-EZ1™ is powered up, it will calibrate during its first read cycle. The sensor uses this stored information to range a close object. It is important that objects not be close to the sensor during this calibration cycle. The best sensitivity is obtained when it is clear for fourteen inches, but good results are common when clear for at least seven inches. If an object is too close during the calibration cycle, the sensor may then ignore objects at that distance. The LV-MaxSonar®-EZ1™ does not use the calibration data to temperature compensate for range, but instead to compensate for the sensor ringdown pattern. If the temperature, humidity, or applied voltage changes during operation, the sensor may require recalibration to reacquire the ringdown pattern. Unless recalibrated, if the temperature increases, the sensor is more likely to have false close readings. If the temperature decreases, the sensor is more likely to have reduced upclose sensitivity. To recalibrate the LV-MaxSonar®-EZ1™, cycle power. For more complete specifications on the MaxSonar-EZ1, please visit www.maxbotix.com

Interference

Since the beam width is fairly large and sound tends to reflect more than light, sonar sensors will interfere with one another if more than one is active in a sensor array. To avoid interference we recommend that you poll each sensor individually and only activate the specific sensor you are polling. That way you can activate one sensor, read the distance, and then deactivate it before moving to the next sensor. This will give you clean results. Perhaps the easiest way to achieve this is to take the power line from the sensor and connect it to a digital output of your InterfaceKit instead of the normal analog input power pin. This will allow you to toggle the power to the device and turn it on or off at will.

Formulas

The formula to translate SensorValue to Distance is:

${\text{Distance (cm)}}={\text{SensorValue}}\times 1.296$

Other Interfacing Alternatives

If you want maximum accuracy, you can use the RawSensorValue property from the PhidgetInterfaceKit. To adjust a formula, substitute (SensorValue) with (RawSensorValue / 4.095) If the sensor is being interfaced to your own Analog to Digital Converter and not a Phidget device, our formulas can be modified by replacing (SensorValue) with (Vin * 200). It is important to consider the voltage reference and input voltage range of your ADC for full accuracy and range.

Each Analog Input uses a 3-pin, 0.100 inch pitch locking connector. Pictured here is a plug with the connections labelled. The connectors are commonly available - refer to the Analog Input Primer for manufacturer part numbers.

API

Phidget analog sensors do not have their own API- they simply output a voltage that is converted to a digital value and accessed through the "Sensor" properties and events on the PhidgetInterfaceKit API. It is not possible to programmatically identify which sensor is attached to the Analog Input. To an InterfaceKit, every sensor looks the same. Your application will need to apply formulas from this manual to the SensorValue (an integer that ranges from 0 to 1000) to convert it into the units of the quantity being measured. For example, this is how you would use a temperature sensor in a C# program:

 // set up the interfacekit object
InterfaceKit IFK = new InterfaceKit();

// link the new interfacekit object to the connected board
IFK.open("localhost", 5001);

// Get sensorvalue from analog input zero
int sensorvalue = IFK.sensors[0].Value;

// Convert sensorvalue into temperature in degrees Celsius
double roomtemp = Math.Round(((sensorvalue * 0.22222) - 61.11), 1);

See the PhidgetInterfaceKit User Guide for more information on the API and a description of our architecture.

For more code samples, find your preferred language on the Languages page.

Product History

Date	Board Revision	Device Version	Comment
February 2008	N/A	N/A	Product Release