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

Quadrature Encoder Phidget

ID: ENC1000_0

Interface a quadrature encoder at speeds of up to 100,000 quadrature cycles per second to a port on your VINT Hub.

$15.00

Quantity Available: 440

Qty Price
5 $14.25
10 $13.50
25 $12.00
50 $10.50
100 $9.75
250 $9.00
500 $8.25
1000 $7.50

A quadrature encoder is the most commonly used feedback device for a DC or stepper motor. With an encoder, you can keep track of how far your motor has turned, which then allows you to control the position and velocity in your code. Whether you want to build a robot whose wheels can respond to uneven terrain or measure the speed of a bicycle, you'll need an encoder and this adapter. The ENC1000 connects to a port on a VINT Hub. See the "Comaptible Products" tab for a list of hubs.



High Compatibility

The Quadrature Encoder Phidget can read incremental encoders with line driver, open collector, or push-pull output circuits by selecting the appropriate mode in our API. For line driver and open collector, you can also choose between 2.2 kΩ or 10 kΩ resistors. Basically, if you have a 0-5V quadrature encoder, this adapter can read it. It can read at speeds of up to 100,000 quadrature cycles per second, which is faster than any motor we sell at Phidgets.

Power Saving Options

If power consumption is imporant in your project, you can turn off the encoder through a command in software when you know the attached device won't be turning. When the encoder is not being powered, this board draws a mere 20μA of current.

Product Specifications

Board Properties
Controlled By VINT
Encoder Interface
Number of Encoder Inputs 1
Count Rate Max 400000 pulses/s
Encoder Interface Resolution x4
Time Resolution 1 μs
Encoder Input Low Voltage Max 2.4 V DC
Encoder Input High Voltage Min 2.6 V DC
Sampling Interval Min 20 ms/sample
Sampling Interval Max 1 s/sample
Pull-up Resistance (Open Collector) 2.2 kΩ or 10 kΩ
Pull-down Resistance (Line Driver) 2.2 kΩ or 10 kΩ
Electrical Properties
Current Consumption Min (unconfigured) 24.6 μA
Current Consumption Max encoder current + 4.2 mA
Physical Properties
Operating Temperature Min -40 °C
Operating Temperature Max 85 °C

Software Objects

Channel NameAPIChannel
Encoder Input Encoder 0

API


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Documents

Library & Driver Downloads

Code Samples

APILanguageOS
Encoder C Multiple Download
Encoder C# Windows Download
Encoder Java Multiple Download
Encoder JavaScript Any Download
Encoder Objective-C macOS Download
Encoder Python Multiple Download
Encoder Visual Basic .NET Windows Download

Projects

Product History

Date Board Revision Device Version Comment
June 20170101Product Release

Getting Started

Welcome to the ENC1000 user guide! In order to get started, make sure you have the following hardware on hand:


Next, you will need to connect the pieces:

ENC1000 Functional.jpeg
  1. Connect the ENC1000 to the VINT Hub using the Phidget cable.
  2. Connect the encoder to the Phidget using an encoder cable.
  3. Connect the VINT Hub to your computer using a USB cable.


Now that you have everything together, let's start using the ENC1000!

Using the ENC1000

Phidget Control Panel

In order to demonstrate the functionality of the ENC1000, 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. 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 ENC1000.

First Look

After plugging the ENC1000 into your computer and opening the Phidget Control Panel, you will see something like this:

ENC1000 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.

Encoder

Double-click on the Encoder object, labelled Quadrature Encoder Phidget, in order to run the example:

ENC1000 Encoder Example.jpg


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

  • Position Change: the number of ticks (or quadrature cycles) that have occurred since the last change event.
  • Time Change: the amount of time in milliseconds that has elapsed since the last change event.
  • Position: the total position in ticks relative to where the encoder was when the window was opened.
  • Index Position: the position where the index channel was last encountered. Some encoders do not support index, check your encoder's datasheet for more information.
  • Velocity: the average velocity in rotations per second. A CPR must be specified to enable this functionality.
  • Specify a counts per revolution (CPR) value to enable velocity calculation.
  • 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.
  • Modify the IO Mode with the drop-down menu. For more information on IO Mode, see the technical section.

Technical Details

General

The ENC1000 can be used with a wide assortment of mechanical and optical encoders. The encoder should be of incremental quadrature output type, indicating that there will be two output channels (usually labeled A and B).

The maximum rate of the ENC1000 is specified at 100,000 quadrature cycles per second. In your application, this number relates directly to the number of revolutions per second you wish to measure, and the number of counts per revolution specified for your encoder. If your encoder's wheel has 1000 cycles per revolution, then the limit on measurable revolutions per second is 100 (6000rpm).

Interfacing Encoders

The ENC1000 can connect to any of the encoders we sell without any modification just by setting the EncoderIOMode property to Push-Pull . If you're trying to use your own encoder, you may need to change the IO mode to Open Collector or Line Driver mode. Have a look at the Encoder Primer for more details on what to use.

Connector

The encoder input on the ENC1000 uses a 5-pin, 0.100 inch pitch locking connector. The connectors are commonly available - refer to the Table below for manufacturer part numbers.

Manufacturer Part Number Description
Molex 50-57-9405 5 Position Cable Connector
Molex 16-02-0102 Wire Crimp Insert for Cable Connector
Molex 70543-0004 5 Position Vertical PCB Connector
Molex 70553-0004 5 Position Right-Angle PCB Connector (Gold)
Molex 70553-0039 5 Position Right-Angle PCB Connector (Tin)
Molex 15-91-2055 5 Position Right-Angle PCB Connector - Surface Mount


Note: Most of the above components can be bought at Digikey.

Calculating Velocity

When your program captures an encoder change event, it will receive two variables: positionChange (measured in 'ticks', four of which equal one quadrature count for the ENC1000) and timeChange (measured in milliseconds). You can use these values to easily compute the instantaneous velocity of the encoder. For example, our C# encoder example implements this method of velocity calculation:


void enc_change(object sender, Phidget22.Events.EncoderEncoderChangeEventArgs e) {

...

// Convert time change from milliseconds to minutes
double timeChangeMinutes = e.TimeChange / 60000.0;
// Calculate RPM based on the positionChange, timeChange, and encoder CPR (specified by the user)
double rpm = (((double)e.PositionChange / CPR) / timeChangeMinutes);

...

}


This implementation may be useful if you're graphing the RPM on a line graph, but if it's being used to display the current RPM as a single number, it won't be very helpful because when the motor changes speed or direction frequently, it'll be hard to read the velocity as a meaningful value. This method can also be prone to variations in velocity if the encoder's CPR is low and the sampling rate is high. To solve these problems, you should decide on a time interval during which you'll gather data, and take a moving velocity calculation based on that data. You can use the Queue data type to make this easy:


Queue<double> positionChangeQueue = new Queue<double>();
Queue<double> timeChangeQueue = new Queue<double>();

void enc_change(object sender, Phidget22.Events.EncoderEncoderChangeEventArgs e) {

double totalPosition = 0;
double totalTime = 0;
int n = 500; // sampling window size, duration is 500*t where t is the data interval of the ENC1000

// add the newest sample to the queue
positionChangeQueue.Enqueue(e.PositionChange);
timeChangeQueue.Enqueue(e.TimeChange);

// If we've exceeded our desired window size, remove the oldest element from the queue
if ( positionChangeQueue.Count >= n ) {
     positionChangeQueue.Dequeue();
     timeChangeQueue.Dequeue();
}

// Calculate totals for position and time
foreach( double positionChange in positionChangeQueue ) {

     totalPosition += positionChange;
}

foreach( double timeChange in timeChangeQueue ) {

     totalTime += timeChange;
}

// Convert time change from milliseconds to minutes
double timeChangeMinutes = e.TimeChange / 60000.0;
// Calculate RPM based on the positionChange, timeChange, and encoder CPR (specified by the user)
double rpm = (((double)e.PositionChange / CPR) / timeChangeMinutes);

}


Check out this project for even more information on encoder velocity.


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.

VINT Hubs

This Phidget is a smart device that must be controlled by a VINT Hub. For more information about VINT, have a look at the VINT Primer. You can use a Phidget Cable to simply and easily connect the two devices. Here's a list of all of the different VINT Hubs currently available:

Product Board
Image Part Number Price Number of VINT Ports
HUB0000_0 $30.00 6
SBC3003_0 $120.00 6

Phidget Cables

Use a Phidget cable to connect this device to the hub. 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

Encoder Cables

For an easy way to connect an encoder to the 5-pin connector on the ENC1000, you can use these handy cables.

Product Physical Properties
Image Part Number Price Cable Length Cable Gauge
3019_0 $5.00 500 mm 26 AWG

Encoders

The ENC1000 can be used with any incremental quadrature encoder. For more details on the different kinds of encoders, have a look at the Encoder Primer. All of the encoders listed below are compatible with this Phidget:

Product Encoder Properties
Image Part Number Price Output Circuit Type Encoder Resolution Encoder Speed Max
3531_0 $25.00 Push-Pull (Single-Ended) 300 CPR 1500 RPM
3532_0 $85.00 Push-Pull (Single-Ended) 360 CPR 4500 RPM

Have a look at our encoder interfaces:

Product Encoder Interface
Image Part Number Price Number of Encoder Inputs Count Rate Max
1047_1B $75.00 4 1E+06 pulses/s
1057_2 $60.00 1 2E+06 pulses/s
ENC1000_0 $15.00 1 400000 pulses/s