AccelerometerSensor
Non-visible component that can detect shaking and measure acceleration approximately in three dimensions using SI units (m/s2). The components are:
- xAccel: 0 when the phone is at rest on a flat surface, positive when the phone is tilted to the right (i.e., its left side is raised), and negative when the phone is tilted to the left (i.e., its right size is raised).
- yAccel: 0 when the phone is at rest on a flat surface, positive when its bottom is raised, and negative when its top is raised.
- zAccel: Equal to -9.8 (earth's gravity in meters per second per second when the device is at rest parallel to the ground with the display facing up, 0 when perpindicular to the ground, and +9.8 when facing down. The value can also be affected by accelerating it with or against gravity.
Properties
AvailableEnabledMinimumInterval- The minimum interval, in milliseconds, between phone shakes
Sensitivity- A number that encodes how sensitive the accelerometer is. The choices are: 1 = weak, 2 = moderate, 3 = strong.
XAccelYAccelZAccel
Events
AccelerationChanged(number xAccel, number yAccel, number zAccel)- Indicates the acceleration changed in the X, Y, and/or Z dimensions.
Shaking()- Indicates the device started being shaken or continues to be shaken.
Methods
noneBarcodeScanner
Component for using the Barcode Scanner to read a barcode
Properties
Result- Text result of the previous scan.
UseExternalScanner- If true App Inventor will look for and use an external scanning program such as "Bar Code Scanner."
Events
AfterScan(text result)- Indicates that the scanner has read a (text) result and provides the result
Methods
DoScan()- Begins a barcode scan, using the camera. When the scan is complete, the AfterScan event will be raised.
Clock
Non-visible component that provides the instant in time using the internal clock on the phone.It can fire a timer at regularly set intervals and perform time calculations, manipulations, and conversions.
Methods to convert an instant to text are also available. Acceptable patterns are empty string, MM/DD/YYYY HH:mm:ss a, or MMM d, yyyy HH:mm. The empty string will provide the default format, which is "MMM d, yyyy HH:mm:ss a" for FormatDateTime, "MMM d, yyyy" for FormatDate. To see all possible format, please see here.
Date and Time are formatted with InstantInTime and Duration.
- Instant : consists of Year, Month, DayOfMonth, Hour, Minute, and Second. An instant can be created by using MakeInstant method.
- Duration : time in milliseconds elapsed between instants. Duration can be obtained by Duration method.
Properties
TimerAlwaysFires- Will fire even when application is not showing on the screen if true
TimerEnabled- Fires timer if true
TimerInterval- Interval between timer events in ms
Events
Timer()- Timer has gone off.
Methods
InstantInTime AddDays(InstantInTime instant, number days)- Returns an instant in time some days after the argument
InstantInTime AddDuration(InstantInTime instant, Duration duration)- Returns an instant in time some time after the argument. Duration can be obtained from Clock.Duration()
InstantInTime AddHours(InstantInTime instant, number hours)- Returns an instant in time some hours after the argument
InstantInTime AddMinutes(InstantInTime instant, number minutes)- Returns an instant in time some minutes after the argument
InstantInTime AddMonths(InstantInTime instant, number months)- Returns an instant in time some months after the argument
InstantInTime AddSeconds(InstantInTime instant, number seconds)- Returns an instant in time some seconds after the argument
InstantInTime AddWeeks(InstantInTime instant, number weeks)- Returns an instant in time some weeks after the argument
InstantInTime AddYears(InstantInTime instant, number years)- Returns an instant in time some years after the argument
number DayOfMonth(InstantInTime instant)- Returns the day of the month(1-31) from the instant
Duration Duration(InstantInTime start, InstantInTime end)- Returns duration, which is milliseconds elapsed between instants
number DurationToSeconds(Duration duration)- Converts the duration to the number of seconds.
number DurationToMinutes(Duration duration)- Converts the duration to the number of minutes.
number DurationToHours(Duration duration)- Converts the duration to the number of hours.
number DurationToDays(Duration duration)- Converts the duration to the number of days.
number DurationToWeeks(Duration duration)- Converts the duration to the number of weeks.
text FormatDate(InstantInTime instant, text pattern)- Returns text representing the date of an instant in the specified pattern
text FormatDateTime(InstantInTime instant, text pattern)- Returns text representing the date and time of an instant in the specified pattern
text FormatTime(InstantInTime instant)- Return text representing the time of an instant
number GetMillis(InstantInTime instant)- Returns the instant in time measured as milliseconds since 1970.
number Hour(InstantInTime instant)- Returns the hour of the day(0-23) from the instant
InstantInTime MakeInstant(text from)- Returns an instant specified by MM/DD/YYYY hh:mm:ss or MM/DD/YYYY or hh:mm. An example text input is "06/22/2015 12:18"
InstantInTime MakeInstantFromMillis(number millis)- Returns an instant in time specified by the milliseconds since 1970.
number Minute(InstantInTime instant)- Returns the minute of the hour (0-59) from the instant
number Month(InstantInTime instant)- Returns the month of the year (1-12) from the instant
text MonthName(InstantInTime instant)- Returns the name of the month from the instant E.g. January, February, March...
InstantInTime Now()- Returns an instant of the current time read from phone's clock
number Second(InstantInTime instant)- Returns the second of the minute (0-59) from the instant
number SystemTime()- Returns the phone's internal time
number Weekday(InstantInTime instant)- Returns the day of the week represented as a number from 1 (Sunday) to 7 (Saturday)
text WeekdayName(InstantInTime instant)- Returns the name of the day of the week from the instant
number Year(InstantInTime instant)- Returns the year from the instant
GyroscopeSensor
Non-visible component that can measure angular velocity in three dimensions in units of degrees per second.
In order to function, the component must have its
Enabled property set to True, and the device must have a gyroscope sensor.Properties
Available- Indicates whether a gyroscope sensor is available.
Enabled- If enabled, then sensor events will be generated and
XAngularVelocity,YAngularVelocity, andZAngularVelocityproperties will have meaningful values. XAngularVelocity- The angular velocity around the X axis, in degrees per second.
YAngularVelocity- The angular velocity around the Y axis, in degrees per second.
ZAngularVelocity- The angular velocity around the Z axis, in degrees per second.
Events
GyroscopeChanged(number xAngularVelocity, number yAngularVelocity, number zAngularVelocity, number timestamp)- Indicates that the gyroscope sensor data has changed. The
timestampparameter is the time in nanoseconds at which the event occurred.
Methods
noneLocationSensor
Non-visible component providing location information, including longitude, latitude, altitude (if supported by the device), and address. This can also perform "geocoding", converting a given address (not necessarily the current one) to a latitude (with the
LatitudeFromAddress method) and a longitude (with theLongitudeFromAddress method).
In order to function, the component must have its
Location information might not be immediately available when an app starts. You'll have to wait a short time for a location provider to be found and used, or wait for the OnLocationChanged eventEnabled property set to True, and the device must have location sensing enabled through wireless networks or GPS satellites (if outdoors).Properties
AccuracyAltitudeAvailableProvidersCurrentAddressDistanceInterval- Determines the minimum distance interval, in meters, that the sensor will try to use for sending out location updates. For example, if this is set to 5, then the sensor will fire a LocationChanged event only after 5 meters have been traversed. However, the sensor does not guarantee that an update will be received at exactly the distance interval. It may take more than 5 meters to fire an event, for instance.
EnabledHasAccuracyHasAltitudeHasLongitudeLatitudeLatitudeLongitudeProviderLockedProviderNameTimeInterval- Determines the minimum time interval, in milliseconds, that the sensor will try to use for sending out location updates. However, location updates will only be received when the location of the phone actually changes, and use of the specified time interval is not guaranteed. For example, if 1000 is used as the time interval, location updates will never be fired sooner than 1000ms, but they may be fired anytime after.
Events
LocationChanged(number latitude, number longitude, number altitude)- Indicates that a new location has been detected.
StatusChanged(text provider, text status)- Indicates that the status of the location provider service has changed, such as when a provider is lost or a new provider starts being used.
Methods
number LatitudeFromAddress(text locationName)- Derives latitude of given address
number LongitudeFromAddress(text locationName)- Derives longitude of given address
NearField
Non-visible component to provide NFC capabilities. For now this component supports the reading and writing of text tags only (if supported by the device)
In order to read and write text tags, the component must have its
ReadMode property set to True or False respectively.
Note: This component will only work on Screen1 of any App Inventor app.
Properties
LastMessageReadModeTextToWriteWriteType
Events
TagRead(text message)- Indicates that a new tag has been detected. Currently this is only a plain text tag, as specified in the manifest. See Compiler.java.
TagWritten()- Event for TagWritten
Methods
noneOrientationSensor
Use an orientation sensor component to determine the phone's spatial orientation.
An orientation sensor is a non-visible component that reports the following three values, in degrees:
- Roll : 0 degree when the device is level, increasing to 90 degrees as the device is tilted up onto its left side, and decreasing to −90 degrees when the device is tilted up onto its right side.
- Pitch : 0 degree when the device is level, increasing to 90 degrees as the device is tilted so its top is pointing down, then decreasing to 0 degree as it gets turned over. Similarly, as the device is tilted so its bottom points down, pitch decreases to −90 degrees, then increases to 0 degree as it gets turned all the way over.
- Azimuth : 0 degree when the top of the device is pointing north, 90 degrees when it is pointing east, 180 degrees when it is pointing south, 270 degrees when it is pointing west, etc.
Properties
Available- Indicates whether the orientation sensor is present on the Android device.
Enabled- If set, the orientation sensor is enabled.
Azimuth- Returns the azimuth angle of the device.
Pitch- Returns the pitch angle of the device.
Roll- Returns the roll angle of the device.
Magnitude- Returns a number between 0 and 1 that indicates how much the device is tilted. It gives the magnitude of the force that would be felt by a ball rolling on the surface of the device.
Angle- Returns an angle that tells the direction in which the device is tiled. That is, it tells the direction of the force that would be felt by a ball rolling on the surface of the device.
Events
OrientationChanged(number azimuth, number pitch, number roll)- Called when the orientation has changed.
ProximitySensor
A sensor component that can measure the proximity of an object (in cm) relative to the view screen of a device. This sensor is typically used to determine whether a handset is being held up to a persons ear; i.e. lets you determine how far away an object is from a device. Many devices return the absolute distance, in cm, but some return only near and far values. In this case, the sensor usually reports its maximum range value in the far state and a lesser value in the near state. It reports the following value:
- Distance: The distance from the object to the device
Properties
Available- Reports whether or not the device has a proximity sensor
Enabled- If enabled, then device will listen for changes in proximity
KeepRunningWhenOnPause- If set to true, it will keep sensing for proximity changes even when the app is not visible
Distance- Returns the distance from the object to the device
MaximumRange- Reports the Maximum Range of the device's ProximitySensor.
Events
ProximityChanged(number distance)- Called when distance (in cm) of the object to the device changes.
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