VCP1002 User Guide

Step 1: Setup

Welcome to the VCP1002 user guide! In order to get started, make sure you have the following hardware on hand:

• VCP1002 - (±1V) Voltage Input Phidget
• VINT Hub
• Phidget cable
• USB cable and computer
• something to use with the VCP1002 (e.g. a voltage source, a voltage output device, etc.)

Next, you will need to connect the pieces:

1. Connect the VCP1002 to the VINT Hub using the Phidget cable.
2. Connect the voltage source to the terminals of the Voltage Input Phidget (ground to the minus terminal, supply to the plus terminal).
3. Connect the VINT Hub to your computer with a USB cable.

Now that you have everything together, let's start using the VCP1002!

Phidget Control Panel

In order to demonstrate the functionality of the VCP1002, the Phidget Control Panel running on a Windows machine will be used.

The Phidget Control Panel is available for use on both macOS and Windows machines.

Windows

To open the Phidget Control Panel on Windows, find the icon in the taskbar. If it is not there, open up the start menu and search for Phidget Control Panel

macOS

To open the Phidget Control Panel on macOS, open Finder and navigate to the Phidget Control Panel in the Applications list. Double click on the icon to bring up the Phidget Control Panel.

For more information, take a look at the getting started guide for your operating system:

• Getting started with Windows
• Getting started with macOS

Linux users can follow the getting started with Linux guide and continue reading here for more information about the VCP1002.

First Look

After plugging the VCP1002 into your computer and opening the Phidget Control Panel, you will see something like this:

The Phidget Control Panel will list all connected Phidgets and associated objects, as well as the following information:

• Serial number: allows you to differentiate between similar Phidgets.
• Channel: allows you to differentiate between similar objects on a Phidget.
• Version number: corresponds to the firmware version your Phidget is running. If your Phidget is listed in red, your firmware is out of date. Update the firmware by double-clicking the entry.

The Phidget Control Panel can also be used to test your device. Double-clicking on an object will open an example.

Part 2: Using Your Phidget

About

The VCP1002 allows you to measure voltages up to ±1V. This Phidget is ideal for small voltage monitoring applications. You can manually select the voltage range (±1V down to ±10mV) in your program to maximize resolution, or use Automatic mode which constantly adjusts the range based on the last voltage measurement.

Explore Your Phidget Channels Using The Control Panel

You can use your Control Panel to explore your Phidget's channels.

1. Open your Control Panel, and you will find the 10-bit (+-1V) Voltage Input Phidget channel:

2. Double click on the channel to open an example program. This channel belongs to the Voltage Input channel class:

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Voltage Input: Measures the voltage across the VCP1002’s terminals

In your Control Panel, double click on "10-bit (+-1V) Voltage Input Phidget":

Part 3: Create your Program

• Code Sample Generator
• Setting up your Programming Environment
• Phidget Programming Basics

Part 4: Advanced Topics and Troubleshooting

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How do I know what channel, serial number, or hub port to use in my program?

Before you open a Phidget channel in your program, you can set these properties to specify which channel to open. You can find this information through the Control Panel.

1. Open the Control Panel and double-click on the red map pin icon:

2. The Addressing Information window will open. Here you will find all the information you need to address your Phidget in your program.

See the Phidget22 API for your language to determine exact syntax for each property.

Setting the Change Trigger and Data Interval

The Change Trigger is the minimum change in the sensor data needed to trigger a new data event.

The Data Interval is the time (in ms) between data events sent out from your Phidget.

The Data Rate is the reciprocal of Data Interval (measured in Hz), and setting it will set the reciprocal value for Data Interval and vice-versa.

You can modify one or both of these values to achieve different data outputs. You can learn more about these properties here.

How can I plot or record sensor data?

Note: Graphing and logging is currently only supported in the Windows version of the Phidget Control Panel.

In the Phidget Control Panel, open the channel for your device and click on the icon next to the data type that you want to plot. This will open up a new window:

If you need more complex functionality such as logging multiple sensors to the same sheet or performing calculations on the data, you'll need to write your own program. Generally this will involve addressing the correct channel, opening it, and then creating an Event Handler and adding graphing/logging code to it.

The quickest way to get started is to download some sample code for your desired programming language and then search google for logging or plotting in that language (e.g. "how to log to csv in python") and add the code to the existing change handler.

Filtering

You can perform filtering on the raw data in order to reduce noise in your graph. For more information, see the Control Panel Graphing page.

Graph Type

You can perform a transform on the incoming data to get different graph types that may provide insights into your sensor data. For more information on how to use these graph types, see the Control Panel Graphing page.

Isolation

The VCP1002 is electrically isolated. A power surge in the circuit being measured would only affect the VCP1002, so your VINT Hub or computer will remain unharmed. Having isolation also helps prevent the formation of ground loops in your system.

With isolation on the VCP1002, you can measure the voltage differential between two points of a circuit regardless of their relation to ground. The voltage differential between those points must be within the specification of the sensor.

For example, in the pictured battery charging circuit, there is sufficient complexity between the current sense resistor (Rsense) and VINT Hub that directly measuring the voltage with a non-isolated sensor could be a risky proposition. However, with VCP1002, the voltage across the resistor may be measured directly, ignoring the circuits in between.

Measuring the voltage across "Rsense" in this circuit is made easy through isolation!

Current Sense Resistors

The VCP1002 is made to measure small voltages anywhere in a circuit. As a result, the VCP1002 is ideal for use with current sense resistors to measure current. For an in-depth look at how to use current sense resistors with the VCP1002, see our article about Current Sense Resistors.