Products for USB Sensing and Control
Products for USB Sensing and Control

PHIDGETS Inc.

Unit 1 - 6115 4 St SE
Calgary AB  T2H 2H9
Canada
+1 403 282-7335

PhidgetBridge 4-Input

ID: 1046_0B
Recommended for new designs: This product (or a similar replacement with a compatible form, fit and function) is estimated to be available for ten years or more.

This board is needed to measure the output from a load cell. You can connect up to four load cells or strain gauges.

$90.00

Quantity Available: 1000+

Qty Price
5 $85.50
10 $81.00
25 $72.00
50 $63.00
100 $58.50
250 $54.00
500 $49.50
1000 $45.00

Note: The 1046_0B is identical to the 1046_0, except that it comes pre-assembled in a plastic shell enclosure and you have the option of which length of USB cable you want to include.

The PhidgetBridge lets you connect up to 4 un-amplified Wheatstone bridges, such as:

  • Strain gauges
  • Compression load cells
  • Pressure sensors/Barometers
  • Piezoresistive accelerometers
  • Magnetoresistive sensors (Compasses)

The data rate and gain values can be configured in software.

Load Cells

Functional

You can connect up to four load cells to the PhidgetBridge in order to measure the amount of strain in the cell. See the product page or manual for your load cell to learn how to hook it up. We have a variety of types available to measure different types of strain: shear, compression, and tension. See the Load Cell Primer for more information.

Product Sensor Properties
Image Part Number Price Sensor Type Weight Capacity Max Creep Zero Balance Cell Repeatability Error Max Cell Non-Linearity Max Cell Hysteresis Max
3132_0 $6.00 Shear Load Cell 780 g 1.6 g/hr ± 11.7 g ± 390 mg 390 mg 390 mg
3133_0 $7.00 Shear Load Cell 5 kg 5 g/hr ± 75 g ± 2.5 g 2.5 g 2.5 g
3134_0 $7.00 Shear Load Cell 20 kg 20 g/hr ± 300 g ± 10 g 10 g 10 g
3135_0 $7.00 Shear Load Cell 50 kg 50 g/hr ± 750 g ± 25 g 25 g 25 g
3136_0 $45.00 Compression Load Cell 50 kg 20 g/hr ± 500 g ± 100 g 100 g
3137_0 $45.00 Compression Load Cell 200 kg * 40 g/hr * ± 2 kg * ± 200 g * 400 g
3138_0 $45.00 Compression/Tension Load Cell 100 kg
3139_0 $7.00 Shear Load Cell 100 g ± 50 mg 50 mg 50 mg
3140_0 $50.00 Compression/Tension Load Cell 500 kg
3141_0 $50.00 Compression Load Cell 1 Mg

Strain Gauges

Strain gauges are ideal for situations where you want to monitor the strain in a material that's already a part of your project. By attaching strain gauges in a strategic way, you can effectively turn a load-bearing member into a custom load cell. You can read strain gauges using the PhidgetBridge by connecting them as described in the Strain Gauge Primer.

Product Sensor Properties Electrical Properties
Image Part Number Price Sensor Type Strain Gauge Mount Type Resistance Value
3142_0 $12.50 Torque Half-bridge Strain Gauge Steel (per quarter-bridge) 1 kΩ
3143_0 $12.50 Torque Half-bridge Strain Gauge Aluminum (per quarter-bridge) 1 kΩ
3144_0 $15.00 Half-bridge Strain Gauge Steel (per quarter-bridge) 1 kΩ
3145_0 $15.00 Half-bridge Strain Gauge Aluminum (per quarter-bridge) 1 kΩ
3146_0 $17.50 Full-bridge Strain Gauge Steel (per quarter-bridge) 1 kΩ
3147_0 $17.50 Full-bridge Strain Gauge Aluminum (per quarter-bridge) 1 kΩ

USB Cables

Use a USB cable to connect this Phidget to your computer. We have a number of different lengths available, although the maximum length of a USB cable is 5 meters due to limitations in the timing protocol. For longer distances, we recommend that you use a Single Board Computer to control the Phidget remotely.

Product Physical Properties
Image Part Number Price Connector A Connector B Cable Length
3017_1 $3.00 USB Type A USB Mini-B 280 mm
3018_0 $4.00 USB Type A USB Mini-B 1.8 m
3020_0 $12.00 USB Type A USB Mini-B 4.5 m
3036_0 $3.50 USB Type A USB Mini-B 600 mm
3037_0 $4.00 USB Type A USB Mini-B 1.2 m


Part 1: Setup

PhidgetTemperatureSensor - Select OS

PhidgetBridge

Welcome to the 1046 user guide! In order to get started, make sure you have the following hardware on hand:

  • a 1046 PhidgetBridge
  • a USB cable and computer
  • a load cell or other sensor to connect to the 1046

Select your Operating System:

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PhidgetBridge - Windows

Step 1: Install Phidgets Library

Step 2: Connect Devices

Step 3: Verify Connection

Step 1: Install Phidgets Library

Before you begin using your Phidgets, you will need to install the Phidget Library.

1. Download the installer for your system:

● 32-bit Installer Download

● 64-bit Installer Download

If you're unsure which one you should get, press ⊞ WIN + Pause/Break:

Before installing our libraries, be sure to read our Software License.

Step 1: Install Phidgets Library

2. Open the download. If it asks you for permission, select Run

Step 1: Install Phidgets Library

3a. Select Next

Step 1: Install Phidgets Library

3b. Read the Licence Agreement. Select Next.

Step 1: Install Phidgets Library

3c. Choose Installation Location. Select Next.

Step 1: Install Phidgets Library

3d. Confirm Install

Step 1: Install Phidgets Library

3e. Wait for Installation to complete. This should only take a few moments.

Step 1: Install Phidgets Library

3f. Installation Complete. Close installation Window.

Step 2: Connect Devices

● Connect USB Cable to your computer and PhidgetBridge

● Connect a load cell or other wheatstone bridge sensor to the PhidgetBridge

Step 3: Verify Connection

1. Open the Phidgets Control Panel:

If your Control Panel does not open, look in your taskbar. Double click the Phidget Icon.

Step 3: Verify Connection

2. If connected, your Phidgets will appear in the Phidget Control Panel.

Done!

If you're able to see and interact with your devices in the Phidget Control Panel, you're done with the Setup part of this guide.

Scroll down to Part 2: Using Your Phidget for the next step.


For more help installing in Windows (e.g. manual install, using a VM, etc.), visit this page:

Windows Advanced Information

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PhidgetInterfaceKit 8/8/8 - MacOS

Step 1: Install Phidgets Library

Step 2: Connect Devices

Step 3: Verify Connection

Step 1: Install Phidgets Library

Before you begin using your Phidgets, you will need to install the Phidget Library.

1. Download the installer for your system:

● OS X 10.11+: Installer Download

● Mac OS X 10.7 - OS X 10.10: Installer Download

● Mac OS X 10.5 - OS X 10.6: Installer Download


Before installing our libraries, be sure to read our Software License.

Step 1: Install Phidgets Library

2. Open the download and double click on Phidgets.pkg

Step 1: Install Phidgets Library

3a. Select Continue

Step 1: Install Phidgets Library

3b. Read and continue. Read the License and click Agree.

Step 1: Install Phidgets Library

3c. Here, you have the option to select the installation location. Select Install to continue.

Step 1: Install Phidgets Library

3d. MacOS may ask for permission to install. Enter your username and password and Install Software.

Step 1: Install Phidgets Library

3e. Wait for Installation to complete. This should only take a few moments.

Step 1: Install Phidgets Library

3f. You may see a message that the extension has been blocked. Select Open Security Preferences.

Step 1: Install Phidgets Library

3g. Beside the message for Phidgets Inc, Click Allow.

Step 1: Install Phidgets Library

3h. Installation Complete, Click Close.

Step 1: Install Phidgets Library

3i. To delete the installer, click Move to Trash.

Step 2: Connect Devices

● Connect USB Cable to your computer and PhidgetBridge

● Connect a load cell or other wheatstone bridge sensor to the PhidgetBridge

Step 3: Verify Connection

1. Open the Phidgets Control Panel:

Step 3: Verify Connection

2. If connected, your Phidgets will appear in the Phidget Control Panel.

Done!

If you're able to see and interact with your devices in the Phidget Control Panel, you're done with the Setup part of this guide.

Scroll down to Part 2: Using Your Phidget for the next step.


For more info installing in MacOS (e.g. developer tools, driver extension, etc.), visit this page:

MacOS Advanced Information

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PhidgetBridge - Linux

Step 1: Install Phidgets Library

Step 2: Connect Devices

Step 3: Verify Connection

Step 1: Install Phidgets Library

1. First, you need to install the libusb-1.0 development libraries. For example, in Debian based distributions:

apt-get install libusb-1.0-0-dev


You’ll also need a C compiler and builder, if you don’t already have one installed.

apt-get install gcc
apt-get install make

Step 1: Install Phidgets Library

2. Next, download and unpack the Phidgets library:

libphidget22

Step 1: Install Phidgets Library

3. Use the following commands in the location you unpacked to install the library:

./configure
make
sudo make install

Step 1: Install Phidgets Library

4. (Optional) You can also download and unpack the following optional packages:

phidget22networkserver - Phidget Network Server, which enables the use of Phidgets over your network

phidget22admin - Admin tool to track who is connected to your Phidgets when using the network server

libphidget22extra - Required for phidget22networkserver and phidget22admin

libphidget22java - The Java libraries for Phidget22


For installation instructions for these packages, see the README file included with each one.

Step 2: Connect Devices

● Connect USB Cable to your computer and PhidgetBridge

● Connect a load cell or other wheatstone bridge sensor to the PhidgetBridge

Step 3: Verify Connection

1. The easiest way to verify that your libraries are working properly is to compile and run an example program. Download and unpack this C example that will detect any Phidget:

HelloWorld C Example

Step 3: Verify Connection

2. Next, open the terminal in the location where you unpacked the example. Compile and run using:

gcc HelloWorld.c -o HelloWorld -lphidget22
sudo ./HelloWorld

ou should receive a “Hello” line for each Phidget channel that is discovered:

I don’t see any Phidgets show up in the HelloWorld example

You need to run it with sudo in order to be able to access USB devices. In order to use Phidgets without sudo, you need to set your udev rules. See the Advanced Information page on the final slide of this guide for details.

Done!

If you're able to see your devices in the Hello World example, you're done with the Setup part of this guide.

Scroll down to Part 2: Using Your Phidget for the next step.


For more info installing in Linux (e.g. Udev rules, old versions, etc.), visit this page:

Linux Advanced Information

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Part 2: Using Your Phidget

About

The PhidgetBridge reads up to four load cells, strain gauges or Wheatstone Bridge-based sensors. The Phidget reports results as a voltage ratio. To convert from voltage ratio to a quantity like weight or force, see the Calibration Guide in the Advanced Topics section.

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 following channels:

1046 Panel.jpg

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

Voltage Ratio Input (Bridge Input): Read data from a load cell

In your Control Panel, double click on "Bridge Input":

1046-VoltageRatio.jpg

Part 3: Create your Program

1. Setting up your Programming Environment

2. Phidget Programming Basics

Part 4: Advanced Topics and Troubleshooting

How can I plot or record sensor data?

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

Plot2.jpg

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.

Choosing a Gain Value

We report the measured voltage in a ratiometric unit known as V/V. This is how the maximum range of sensors that use strain gauges is usually specified. V/V is the output value in V of the measured sensor, scaled for a 1V sensor supply voltage. This value will correspond to the physical quantity that the sensor is measuring, regardless of the actual voltage supplied to the sensor.


Gain Resolution Range
1 119 nV/V ± 1000 mV/V
8 14.9 nV/V ± 125 mV/V
16 7.45 nV/V ± 62.5 mV/V
32 3.72 nV/V ± 31.25 mV/V
64 1.86 nV/V ± 15.625 mV/V
128 0.93 nV/V ± 7.8125 mV/V


When choosing the Gain setting, it's best to use the highest gain possible that can still measure the full range of your sensor. For an individual unit, you can apply the maximum stimulus to the sensor, and ensure the voltage ratio reported is well within the range for the gain setting you have chosen. If many units are being deployed, it’s best to consult the data sheet for the strain gauge and look for maximum offset.


Some wheatstone bridges, most often those produced from silicon and used in pressure sensors, will have a very wide offset, and large manufacturing variation in the offset. This will restrict the gain to lower settings, particularly if the application must support a number of deployed systems with the expected variation. Fortunately, the very high precision electronics used in the 1046 means that in many application, higher gain is not necessary to get adequate accuracy and resolution.

Connecting Your Strain Gauge or Load Cell

Load cells are pressure sensors that can be used with the 1046. For more information, see our Load Cell Primer.


If no documentation is available for your strain gauge, it’s possible to use a multimeter to determine how to connect it, provided there are no electronics in the sensor. First, measure resistance between the 4 wires. There are 6 combinations - two combinations will have a resistance 20-40% higher than the other four. Choose one of these high-resistance combinations, and wire it into 5V and G on the 1046. Connect the other two wires into +/-. Apply a load, if the V/V responds in the opposite way to your expectations, flip the +/- wires.

Measurement Considerations

The 1046 is designed to measure voltages as a ratio of the supply voltage - it’s not practical to make measurements of absolute voltages with this product.


For maximum accuracy, all wires from the 1046 to the sensor should be the same length and thickness. Changes in temperature will change the resistance of the wires - if they are all the same, the errors will cancel out.


Each bridge input can be powered down, reducing power consumption with 1046 sensors, and useful for reducing heating of sensors, which can introduce errors.

The number I’m getting back from the 1046 is really small

Load cells output a small voltage proportional to the amount of strain they are currently experiencing. The rated output for most load cells at full load is in the order of millivolts, so when you’re only straining the load cell at a fraction of its full load, you will get very small values. In order to convert to meaningful units like grams or newtons, you need to calibrate the load cell.

Calibration

We have observed a 1.5% difference between a 1x gain and an 8x gain. This may require that each system (1046 and sensors) be calibrated as a whole. For maximum accuracy, decide on, and keep with a chosen gain before calibrating the system.

Expensive sensors will ship with a certificate of calibration specifying, often in mv/V, how the sensor responds to stimulus. Less expensive will have to be calibrated

For an in-depth guide on calibration, see Calibrating Analog Sensors.

Measuring RTDs

Measuring Resistive Thermal Devices (RTD)

Using a Wheatstone Bridge

This diagram shows how to connect the RTD to a Wheatstone bridge, and then to a PhidgetBridge 4-Input.

A Wheatstone bridge is the classic method of measuring unknown resistances, and requires three resistors of known values. It uses the current in each leg of the bridge to create a voltage differential between both voltage dividers. Using the voltage differential and the three known resistors, the resistance of the fourth resistor can be determined.

To determine the resistance of the RTD, the following formula can be used:



Where is the Bridge Value given by the PhidgetBridge (in mV/V) , and , and are the resistances of the known resistors.


Using a Voltage Divider

The alternate method requires only two resistors. This reduces the amount of error that can be introduced into the system due to resistor tolerances. A voltage is applied to the two resistors and the RTD in series. The voltage drop across the RTD is measured. Using the voltage drop and the values of the two resistors, the resistance of the RTD can be determined.

This diagram illustrates how to connect the RTD to the PhidgetBridge with a voltage divider cirtuit.

To determine the resistance of the RTD, the following formula can be used:



Where is the Bridge Value given by the PhidgetBridge (in mV/V) , and and are the resistances of the known resistors.

Getting Higher Accuracy

In order to get the highest accuracy from the RTD, consider the following:

  • Use resistors with a high degree of tolerance. There will be less variability in the manufacturing of 0.1% resistors when compared to 1% resistors.
  • Measure the known resistors with an ohmmeter. By obtaining the most accurate measurements for the known resistances, the formula will result in a more accurate measurement of the RTD.
  • Use a moving average when obtaining the Bridge Value to reduce the amount of noise in the measured signal.
  • Estimate or Measure the resistance of the +5V and GND wires between the RTD and the 1046 PhidgetBridge. Add this resistance to the two resistors.
  • Turn off the power to the RTD (by disabling the channel on the PhidgetBridge) to reduce self-heating of the RTD.
  • By using higher resistor values (> 1 Kilo ohm), there will be less self-heating of the RTD, but the resolution of the measurement will be reduced somewhat. We recommend 1 Kilo Ohm resistors as a reasonable trade off.
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. You can modify one or both of these values to achieve different data outputs. You can learn more about these two properties here.

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:

The locate Phidget button is found in the device information box

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

All the information you need to address your Phidget


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

Product Specifications

Board
Controlled By USB (Mini-USB)
API Object Name Bridge
Number of Bridge Inputs 4
Bridge Data Rate Min * 8 ms
Bridge Data Rate Max 1000 ms
Bridge Input Current Max ± 3 nA
Differential Voltage Resolution 24 bit
Electrical Properties
USB Voltage Min 4.5 V DC
USB Voltage Max 5.3 V DC
USB Speed Full Speed
Current Consumption Min 35 mA
Current Consumption Max 500 mA
Available External Current 465 mA
Input Voltage Limit Min Ground + 0.25V DC
Input Voltage Limit Max 5V Supply - 0.25V DC
Physical Properties
Recommended Wire Size 16 - 26 AWG
Operating Temperature Min 0 °C
Operating Temperature Max 70 °C
Customs Information
Canadian HS Export Code 8471.80.00
American HTS Import Code 8471.80.40.00
Country of Origin CN (China)
*The minimum data rate is 8ms though the board has a maximum sample rate of 122 samples a second (slightly less than the 125 an 8ms rate would have you believe).

Documents

Product History

Date Board Revision Device Version Packaging Revision Comment
May 20110100Product Release
May 20110101getLabelString fixed for labels longer than 7 characters
February 20140102Various fixes: usb stack, gain switching, bad values after enable
January 20180102BAdded plastic shell enclosure, removed USB cable

Software Objects

Channel NameAPIChannel
Bridge Input VoltageRatioInput 0 - 3

API


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Code Samples



Example Options


Downloads

				Make your selections to display sample code.
					

Code Samples

Language:

APIDetailLanguageOS
VoltageRatioInput Visual Studio GUI C# Windows Download
VoltageRatioInput Load Cell Calibrator C# Windows Download
VoltageRatioInput Java Android Download
VoltageRatioInput JavaScript Browser Download
VoltageRatioInput Objective-C macOS Download
VoltageRatioInput Swift macOS Download
VoltageRatioInput Swift iOS Download
VoltageRatioInput Visual Basic .NET Windows Download
VoltageRatioInput Max/MSP Multiple Download

Here are our Bridge Interfaces:

Product Board
Image Part Number Price Controlled By Number of Bridge Inputs
1046_0B $90.00 USB (Mini-USB) 4
DAQ1500_0 $30.00 VINT 2