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

Voltage Divider

ID: 1121_0

This adapter lets you interface with all sorts of non-Phidgets resistance sensors, just dial in the resistance you want.

$7.00

Quantity Available: 1000+

Qty Price
5 $6.65
10 $6.30
25 $5.60
50 $4.90
100 $4.55

The 1121 provides an interface to non-Phidgets resistance sensors such as: Force-Sensing Resistors (FSR), light sensors, thermistors (heat sensors), and bend sensors.

The Voltage Divider eliminates the need to connect a resistor to an analog input by putting a high precision potentiometer on the board to allow the adjustment of the 'fixed' resistor.

The interface to the variable resistance sensor is a convenient terminal block.


Comes packaged with

Product Specifications

Sensor Properties
Sensor Type Resistance
Controlled By VoltageRatio Input
Sensor Output Type Ratiometric
Resistance Min 1 kΩ
Resistance Max 21 kΩ
Optimal Measurement Resistance Min (@ 1kΩ) 100 Ω
Optimal Measurement Resistance Max (@ 1kΩ) 10 kΩ
Optimal Measurement Resistance Min (@ 21kΩ) 2 kΩ
Optimal Measurement Resistance Max (@ 21kΩ) 200 kΩ
Electrical Properties
Current Consumption Max 5 mA
Supply Voltage Min 3 V DC
Supply Voltage Max 5.3 V DC
Physical Properties
Recommended Wire Size 12 - 24 AWG
Operating Temperature Min -40 °C
Operating Temperature Max 105 °C

Documents

Projects

Product History

Date Board Revision Device Version Comment
August 2007 0 N/A Product Release

Getting Started

Welcome to the 1121 user guide! In order to get started, make sure you have the following hardware on hand:


Next, you will need to connect the pieces:

1121 0 Connecting The Hardware.jpg
  1. Connect the 1121 to the 1018 with the Phidget cable.
  2. Connect a variable resistance sensor to the terminal block on the 1121. Polarity doesn't matter.
  3. Connect the 1018 to your computer with the USB cable.


Now that you have everything together, let's start using the 1121!

Using the 1121

Phidget Control Panel

In order to demonstrate the functionality of the 1121, we will connect it to the 1018, and then run an example using the Phidget Control Panel on a Windows machine.


The Phidget Control Panel is available for use on both macOS and Windows machines. If you would like to follow along, first take a look at the getting started guide for your operating system:


Linux users can follow the getting started with Linux guide and continue reading here for more information about the 1121.

First Look

After plugging in the 1121 into the 1018, and the 1018 into your computer, open the Phidget Control Panel. You will see something like this:

1018 Panel.jpg


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.

Voltage Ratio Input

Double-click on a Voltage Ratio Input object in order to run the example:

1018 Sensors VoltageRatioInput.png


General information about the selected object will be displayed at the top of the window. You can also experiment with the following functionality:

  • Modify the change trigger and/or data interval value by dragging the sliders. For more information on these settings, see the data interval/change trigger page.
  • Select the 1121 from the Sensor Type drop-down menu. The Sensor Value will now return a value between 0 and 1.


Technical Details

Configuring the Voltage Divider

Why is adjusting the resistance important? The Voltage Input can measure a voltage between 0V and 5V. When using variable resistance devices a voltage divider is commonly used to measure the changing resistance. The two resistors in the divider form a voltage, based on the ratio between them. This voltage is then measured by the Voltage Input. To optimize the voltage divider to meet your needs, you have to adjust the fixed resistance to match the characteristics of your chosen sensor. To adjust the resistance on the 1121, simply turn the screw on the potentiometer clockwise to decrease the resistance and counterclockwise to increase it. You'll see a change in resistance of about 900Ω to 1000Ω per revolution. First, adjust the resistance for no stimuli on your sensor and then apply the maximum possible stimuli and make sure that sensor's voltage stays within a range that gives you acceptable resolution. At the extremes (less than 0.25V or greater than 4.75V), a very large change in stimuli (and therefore change in the resistance) produces only a small change in voltage. Keep adjusting until you get a range you are happy with.


1121 0 Schematic.jpg

Non-Phidgets Sensors

Type Website Search Term Example
Light Sensor Digikey photocell PDV-P9003-1
Force Sensor Digikey force sensor IESP-12
Force Sensor Trossen Robotics Force Sensing FSRs n/a
Thermistor Digikey Thermistor Radial Choose a thermistor with a resistance in the range 10K ohms.

Phidget Cable

Analoginput.jpg

The Phidget Cable is 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.

What to do Next

  • Software Overview - Find your preferred programming language here to learn how to write your own code with Phidgets!
  • General Phidget Programming - Read this general guide to the various aspects of programming with Phidgets. Learn how to log data into a spreadsheet, use Phidgets over the network, and much more.
  • Phidget22 API - The API is a universal library of all functions and definitions for programming with Phidgets. Just select your language and device and it'll give you a complete list of all properties, methods, events, and enumerations that are at your disposal.

Interlink Force-Sensitive Resistors

This adapter can be used to interface one Interlink FSR. Here's a complete list of all the different varieties we sell:

Product Sensor Properties Physical Properties
Image Part Number Price Force Min Force Max Sensing Area
3103_0 $6.50 1 N 20 N 19.6 mm²
3104_0 $7.50 1 N 20 N 126.7 mm²
3105_0 $10.00 1 N 20 N 14.5 cm²

Interface Boards and Hubs

This adapter can be read by any Phidget with an Analog Input or VINT Hub port. It will connect to either one using the included Phidget cable. VINT Hub ports can behave just like Analog Inputs, but have the added flexibility of being able to be used as digital inputs, digital outputs, or ports to communicate with VINT devices. For more information about VINT, see the VINT Primer.

Product Voltage Inputs
Image Part Number Price Number of Voltage Inputs Voltage Input Resolution
1010_0 $80.00 8 10 bit
1011_0 $50.00 2 10 bit
1018_2 $80.00 8 10 bit
1019_1 $115.00 8 10 bit
1203_2 $125.00 8 10 bit
DAQ1000_0 $20.00 8 12 bit
HUB0000_0 $30.00 6 (Shared) * 16 bit
SBC3003_0 $120.00 6 (Shared) * 16 bit

Phidget Cables

This adapter comes with its own Phidget cable to connect it to an InterfaceKit or Hub, but if you need extras we have a full list down below. You can solder multiple cables together in order to make even longer Phidget cables, but you should be aware of the effects of having long wires in your system.

Product Physical Properties
Image Part Number Price Cable Length
3002_0 $2.00 600 mm
3003_0 $1.50 100 mm
3004_0 $3.00 3.5 m
3034_0 $1.50 150 mm
3038_0 $2.25 1.2 m
3039_0 $2.75 1.8 m

Here are all of the boards that can divide voltage down:

Product Sensor Properties
Image Part Number Price Resistance Min Resistance Max
1121_0 $7.00 1 kΩ 21 kΩ
1134_0 $15.00 172 Ω 1 MΩ