Template:PT3 MAX MAC

Language - Max/MSP

MacOS with Max/MSP

Welcome to using Phidgets with Max/MSP! By using Max/MSP, you will have access to the complete Phidget22 API, including events.

Phidget22 supports Max/MSP versions 6 and up.

Requirements

First, make sure you have the following installed:

● Phidgets Drivers for MacOS (see Part 1 of this user guide)

● Max/MSP

Use Our Examples

Next, download and unpack the Phidgets Max/MSP library:

● Phidget Max/MSP library

Use Our Examples

After unpacking the download, navigate to the externals folder and copy it to your clipboard:

Use Our Examples

The folder you copied needs to be placed in a specific location for Max/MSP to reference it. Open Max/MSP and navigate to Options -> File Preferences.

You will see something similar to this:

Use Our Examples

The folder that you copied earlier needs to be placed in any of the locations listed in File Preferences. Navigate to one of the locations and paste the folder:

Use Our Examples

The Phidget Max/MSP library is now being referenced. Next, navigate to the examples folder located within the Phidget22MaxMSP folder you previously unpacked:

Use Our Examples

From here, select an example that will work with your Phidget and open it in Max/MSP. You can run the example by simply pressing the start button:

The example is now running. Play around with the device and experiment with some of the functionality. When you are ready, the next step is configuring your project and writing your own code!

Write Code

You should now have working examples and a project that is configured. This teaching section will help you understand how the examples were written so you can start writing your own code.

Remember: your main reference for writing Max/MSP code will be:

● The Phidget22 API Manual

● The Max/MSP examples

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First, let's explain how to operate the examples. We will take a look at the PhidgetVoltageInput example:

For this particular example, the Max object is called PhidgetVoltageInput. Objects/message boxes are connected to the inputs and outputs of this object. Input objects will either cause a property of the device to change or request for a property to be retrieved. Output objects return the retrieved information.

All supported functions for Max/MSP can be found in the Phidget22 API.

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Try it for yourself! Click on the getDeviceSerialNumber message box to request the Phidget to retrieve the serial number of the device. You should see the a message in the Max window denoting the serial number of your device. All devices support the getDeviceSerialNumber message, making it an easy way to determine if the Phidget libraries are correctly set up, and whether the Max/MSP application is connected to your device.

If your example contains a get[DataType] message box (e.g. getVoltage), click on it to cause the associated data to be output with a relevant prefix. [DataType] can be data member the object has. A list of available messages and their associated outputs is outlined in the Phidget22 API for your device.

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If your example contains the start message box, you can continuously poll for events. Just press the start message box to start sampling. When an event occurs on a Phidget (i.e. when a sensor detects a change in the measured data), associated data will be output with related prefixes. Press the stop message box to stop sampling.

For the PhidgetDigitalOutput example, there are setDutyCycle and setState message boxes. Changing the numbers will cause the digital output to change. Your example may contain device specific message boxes to click on. Click them to see what they do!

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Your best resource to program in MaxMSP will be our examples. If you aren't familiar with concepts in Phidget programming, you may find our Phidget Programming Basics page helpful. It provides a very generic overview of what traditional languages follow when using Phidgets. For Max users, conceptual details about particular actions (e.g. opening a Phidget) are explained there.

Keep in mind when reading these general resources that the Max/MSP libraries may not implement the full Phidgets API - some function calls and Phidget classes may not be supported.

In general, Phidget objects can be placed inside the patcher, and functions can be called on them using appropriately connected messages. We'll go over a basic setup next.

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Step One: Initialize and Open

Initializing and opening the device is be done by placing a new object. Other objects handle different Phidgets - a Spatial, a Light Sensor, a Motor Controller, etc. Only the name of the object changes. You can find the name for the object in the device's .maxhelp file (e.g. VoltageInput.maxhelp). If you are unsure what the software object for your device is, go to the API tab on its product page on our website.

In the case of a Voltage Input, we name it PhidgetVoltageInput:

Important: a local connection will reserve the device until closed. This prevents any other instances from retrieving data from the Phidget, including other programs. Every Phidget object in Max will automatically try to connect to and reserve a Phidget for itself. As long as a MaxMSP Phidget object is running, it will continuously try to connect to a Phidget, even trying to reconnect if it gets disconnected.

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Specifying a Phidget

When the instance is created as with the Voltage Input above, normally it will make a connection to the first device of its type it can find. The Phidget object can also be declared with a number of specifiers to open a specific Phidget instead.

Specifiers can be added to the object in the format: PhidgetExternal {Specifiers}. These will be written in the form: specifier=value

The full list of specifiers that can be used to identify a Phidget in Max/MSP are as follows:

• serialnumber - The serial number of the device
• channel - The channel of the device to open
• hubport - The hub port the device is plugged into (where applicable)
• ishubport - Specifies whether this channel should be opened on a hub port directly, or on a VINT device attached to a hub port.
• remote - Forces connection to a remote device over a network, ignoring devices on the local machine
• local - Forces connection to a device plugged into the local machine, ignoring network devices

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Specifying a Phidget

For instance, to open a VoltageInput with serial number 349428, you would use:

Some other examples:

Open a Digital Input:

PhidgetDigitalInput

Open channel 1 of a Digital Input Phidget connected to port 2 of a hub with serial number 35569

PhidgetDigitalInput serialnumber=35569 channel=1 hubport=2

Open open hub port 2 as a DigitalInput for a hub with serial number 35569

PhidgetDigitalInput serialnumber=35569 hubport=2 ishubport=1

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Using a Phidget Over a Network

To use the Network Server, first the Phidget needs to be plugged in to a computer that has the Network Server turned on within your local network. (For information on how to do this, see the Phidget Network Server page in the section on how to use the Network Server for your operating system).

Next, in your patch you need a PhidgetNet object. To automatically find local networks, send it a message saying enableServerDiscovery.

Then, to connect a Phidget over the network, change the object text to specify it is to connect to a Phidget on a remote server, as per the following example.

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Step Two: Wait for Attachment (plugging in) of the Phidget

Although this is a required step in many of our other languages (and therefore you may be expecting this if coming from another Phidget language), in MaxMSP you do not have to add a specific waitForAttachment block.

Keep in mind, however, that if your Phidget is not responding within your MaxMSP program, it may simply not be plugged in! Send a getAttached message to a Phidget object at any time to see if it's attached.

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Step Three: Do Things with the Phidget

Phidget data is accessed either by one-time polling or at a fixed rate via on-board timers for some devices.

Getting or setting values directly via polling on the Phidget is done through messages linked to the inlet. The object’s inlet can be wired to send commands to the device, and the outlet used to retrieve the results. You can set values on the Phidget by using the set messages, and some properties can be read with get messages:

To sample at a fixed rate, use the start and stop messages to start and stop the data flow, respectively.

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Step Three: Do Things with the Phidget

Outlet data is always given a prefix to allow for routing. For instance, the digital input state state change event data is given the prefix stateChange, and the voltage input voltage change event similarly use voltageChange. The specific prefixes for each set of outlet data is listed on the API page for that class.

The rightmost outlet on the Phidget object outputs error event data. This will send information on error events such as saturation events. To see which error events may apply to your device, check its API page.

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Step Four: Close and Delete

Although this is a required step in many of our other languages (and therefore you may be expecting this if coming from another Phidget language), in MaxMSP you do not have to add a specific close and delete block.

Special Case: Multiple Phidgets

Multiple Phidgets of the same type can easily be used inside a single program, it only requires another Phidget object placed. If two of the same type of Phidget object are placed, the serial number and channel arguments should always be specified (as well as hub port, if applicable) to ensure that the correct Phidget gets associated with the correct object.

What's Next?

Now that you've set up Phidgets in your programming environment, you should read our guide on Phidget Programming Basics to learn the fundamentals of programming with Phidgets.

Continue reading below for advanced information and troubleshooting for your device.

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