JOHNS HOPKINS UNIVERSITY, PHYSICS AND ASTRONOMYBASIC PHYSICS LABORATORIES (AS.173.XXX)

Physics Toolbox User Guide

1 INTRODUCTION

The Physics Toolbox is an app that can be used to record experimental data using the sensors on yoursmartphone.

2 INSTALLATION

Several apps exist for collecting data from these packaged sensors. The one that we will use in this lab is“The Physics Toolbox Sensor Suite”.

Download the free app that is appropriate to your device using the links below:

iOS Devices: Physics Toolbox Sensor Suite

Android: Physics Toolbox Sensor Suite

The app is not available for Windows phones.

3 MAKING MEASUREMENTS

3.1 USING THE PHYSICS TOOLBOX – IOS

These instructions describe how to use the Physics Analysis Toolbox on an iOS device. For instructionson how to use the app with an Android device skip to Section 3.2.

Data is recorded with the Physics Toolbox App using the following steps:

• Step 1: Open the Physics Toolbox App

• Step 2: Select the g-Force Setting

• Step 3: Record Data

• Step 4: Stop Data Collection

• Step 5: Share the Data

Detailed instructions for each step follow:

Revised: Thursday 10th October, 2019 14:21 ©2014 J. Reid Mumford

3.1.1 STEP 1: OPEN THE PHYSICS TOOLBOX APP

Open that Physics Toolbox Sensor Suite app by clicking on the icon shown in Figure 3.1.

Figure 3.1: The Physics Toolbox Sensor Suite icon on iOS.

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3.1.2 STEP 2: SELECT THE G-FORCE SETTING

The iOS version of the Physics Toolbox has several sensors available. Select the “g-Force Meter” (seeFigure 3.2).

Figure 3.2: The Physics Toolbox Sensor Suite home screen on iOS.

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3.1.3 STEP 3: RECORD DATA

When you are ready to collect data, press the record button (circle with “+” – see Figure 3.3). The phonewill begin to record data from the accelerometer.

The pause button freezes the real-time plot of the acceleration data. In general, the pause button will notbe used as are interested in looking at the acceleration data that is stored in the .csv file.

Figure 3.3: Ready to collect g-Force Meter data with the Physics Toolbox on iOS.

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Figure 3.4: When recording data, the record button becomes a “stop” icon.

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3.1.4 STEP 4: STOP DATA COLLECTION

When the data collection is stopped with the stop button (see Figure 3.4), Physics Toolbox will immedi-ately prompt you for what to do with the data file (see Figure 3.5). The Physics Toolbox creates a comma-separated file (.csv) that will contain all of the collected sensor data. The file is called “sensor.csv”. Whensubsequent data is collected and stored on your iOS device, the files will be named “sensor-1.csv”, “-2”,etc. It is important to keep good records, or rename the files, so that you can keep track of your data.

Figure 3.5: When data collection is stopped, a file named “sensor.csv” is created. The appthen prompts you for a method of saving the data file.

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3.1.5 STEP 5: SHARE THE DATA

At this point, the data file has been created and can be shared in several different ways. The three simplestoptions for getting the .csv file off of your device are likely to either:

1. share the file using Apple’s Airdrop.

2. save the file to your Google Drive if you have a Google drive account.

3. e-mail the file to yourself.

4. save the file to Files and then access using iCloud.

See Figure 3.5. Depending on the software that is installed on your device there may be different optionsavailable to you.

Note: it is a good idea to give your e-mail subject or file directory a descriptive name so that you’llbe able to identify the data later. For example, you might choose a name like: “Phone Drop Trial 2MM-DD-YYYY”.

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3.2 USING THE PHYSICS TOOLBOX – ANDROID

Data is recorded with the Physics Toolbox App using the following steps:

• Step 1: Open The Physics Toolbox App

• Step 2: Configure CSV Timestamp

• Step 3: Select the Sensors

• Step 4: Record Data

• Step 5: Stop Data Collection

• Step 6: Share the Data

Detailed instructions for each step follow:

3.2.1 STEP 1: OPEN THE PHYSICS TOOLBOX APP

Open that Physics Toolbox Sensor Suite app by clicking on the icon shown in Figure 3.6.

Figure 3.6: The Physics Toolbox Sensor Suite icon on Android.

3.2.2 STEP 2: CONFIGURE CSV TIMESTAMP

Configure the way that the Physics Toolbox will record data by clicking on the gear icon on the upperright. It is generally most convenient if the .csv file is recorded with the time counting up from 0 secondswhen the record button is pushed. Enable this functionality by configuring the CSV Timestamp Formatso that the Elapsed time option is checked (see Figure 3.7).

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Figure 3.7: When Elapsed time: Start from 0 timestamp on CSV file is checked the Physics Tool-box will record the data from t = 0 when the record button is pushed.

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3.2.3 STEP 3: SELECT THE SENSORS

Depending on the device there may be several sensors available. The list of sensors is accessed throughthe menu on the top-left of the screen (see Figure 3.8). An example of some of the sensor options is shownin Figure 3.9.

For this activity the “g-Force Meter” setting will be adequate. Note that the g-Force Meter expresses theacceleration in terms of g . An acceleration of 1 will be measured when the device is at rest. In free-fall,the acceleration is zero. The Physics Toolbox shows the acceleration in each axis as well as the magnitudeof the acceleration vector.

Figure 3.8: The home screen on Android. The app immediately displays sensor readingswhen it is opened.

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Figure 3.9: Different sensors can be selected using the Menu in the upper left corner. Theg-Force meter is what will be used in this activity.

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3.2.4 STEP 4: RECORD DATA

When you are ready to collect data, press the red record button (see Figure 3.8). The phone will begin torecord data. Note that when data is recording, the record button will change to a stop button (see Figure3.10). Additionally, the phone should remain on, with the screen active, while acquiring data.

Figure 3.10: When recording data, the record button becomes a stop button.

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3.2.5 STEP 5: STOP DATA COLLECTION

When the data collection is stopped with the stop button, Physics Toolbox will immediately prompt youfor a file name. The Physics Toolbox will create a comma-separated file (.csv) that will contain all of thesensor data that was collected. Enter a file name at the prompt. Note that the .csv extension will beincluded automatically. See Figure 3.11.

Note: it is a good idea to give your file a descriptive file name so that you’ll be able to identify the datalater. In Figure 3.11, a poorly named, non-descriptive file name is shown. Better to use something like:“Phone Drop Trial 2 09-28-2016”, that is more descriptive.

Figure 3.11: When data collection is stopped, a .csv file is created. Here the file name ischosen.

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3.2.6 STEP 6: SHARE THE DATA

At this point, the file has been created and can be shared in several different ways. The two simplestoptions for getting the .csv file off of your device are likely to either:

1. save the file to your Google Drive if you have a Google drive account.

2. e-mail the file to yourself.

See Figure 3.12. Depending on the software that is installed on your device there may be different optionsavailable to you.

Figure 3.12: The simplest options for getting the .csv file off of your device is to either tosave it to a Google Drive account or e-mail the file to yourself.

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