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Line 1: − [[Image:Measure-icon.svg]]+ − ==About==+ − This Activity draws a picture of the sound heard by the internal microphone or of the signal present on the microphone socket. More specifically it draws a graph of this input versus time, the input is on the vertical axis and time is on the horizontal axis. That is, the laptop functions like a machine called an oscilloscope. − As well as graphing signal as a function of time, Measure can also graph as a function of frequency.+ − − The XO-1 laptop is only capable of mono input, the XO-1.5 and XO-1.75 are capable of stereo input on their microphone socket and can graph two signals at once. − − '''Note:''' As of Measure Version 37, older versions of Sugar, e.g. 0.84, are no longer supported. − − [[File:Measure tut 1 24.jpg|center|300px]] − − ===Where to get Measure=== − − http://activities.sugarlabs.org/en-US/sugar/addon/4197/ − − ==Using== − [[image:Measure-screen.JPG|600px|center]] − − ;1. Select secondary toolbar: Allows the Activity's Journal entry to be renamed − − ;2. Select secondary toolbar: Measurement settings − − ;3. Select secondary toolbar: Tuning settings − − ;4. Time base/frequency: Plots the signal vs. time or plots amplitude vs. frequency − − ;5. The time scale: Used to scale the plot − − ;6. Freeze the display: Pause the program − − ;7. Capture sample now: Saves an image of the wave in the Sugar Journal − − ;8. Stop: Exits the Activity − − ;9. Mute: Mute/unmute channel − − ;10. Invert: invert the display − − ;11. Amplitude adjustment: Use these sliders to control the sensitivity − − ;12. Caption: A summary of current settings that are selected − − ===Sensor toolbar=== − [[File:Measure2ndtoolbar.JPG|600px|center]] − − − − ;13. Sound: Use this setting with the internal microphone, external microphone and external AC signals − − ;14. Resistance sensor: Use with external resistive type transducers − − ;15. Voltage sensor: Use with external sensors which generate a voltage − − ;16. Sample interval: A log file 'Measure Log' is saved to the journal, it contains one sample per interval − − ;17. Starts/stops saving a log file: 'Measure Log' with measured values as readable text − − ;18. Trigger: Synchronise the sample period to the waveform so that the sample will start on a rising edge or falling edge − − ''There is no 19.'' − − '''Note:''' Whenever you switch sensing modes, Measure switches to time-base plotting. − − ===Tuning toolbar=== − − − The tuning toolbar - frequency settings − − '''Hint:''' Adjust the time scale (#5) to increase the spacing between the tuning lines. − − ;20. Instrument: Select instrument to tune. − − ;21. Note entry: Select a note for tuning. (When an Instrument is selected, the notes are restricted to the open notes of that instrument; when no instrument is selected, any of the 88 notes on a piano can be selected.) − − ;22. Frequency entry: The frequency of the target note is displayed. (The user can also enter a frequency to target.) − − ;23. Show/hide tuning mark: A tuning mark displays the target note on the plot. − − ;24. Show/hide harmonics: Harmonic lines are integer multiples of the target frequency. − − ;25. Play a note: Plays a five-second sample of the target note. (Sampling is disabled while the note is playing.) − − ;26. Measured note: An estimate of the note being played is displayed. If the note is slightly flat or sharp, relative to the target, it is displayed in color (red == very flat or sharp; yellow == somewhat flat or sharp). − − '''Note:''' Whenever you switch to a tuning mode, Measure switches to frequency-base plotting. − − ====Measuring A5 (880 HZ)==== − [[Image:Measure-tuning.JPG|600px|center]] − − ====Guitar tuning lines==== − [[Image:Measure-guitar.png|600px|center]] − − ==Applying== − Let the children experiment with the internal microphone, try singing, whistling, musical instruments, the Tam Tam musical Activity. The Turtle Blocks Activity can generate an audio tone. − − The children should learn through guided discovery that: − * sound is a pressure wave − * the pitch of the sound is determined by the frequency or cycles per second (Hz) − * the loudness of a sound is determined by the amplitude − * sounds contain multiple frequency components or harmonics − * the more pure sounds have less harmonics − − Sameer has a [http://www.youtube.com/watch?v=6nqDsYf_I7M&feature=youtu.be video] of using Measure to analyze dual-tone singing from Tuva. − − ==Sharing== − This Activity does not currently support sharing. However, it is useful to use one XO for measuring and another for generating sounds. − − ==Extending== − Measure is able to take input from a wide range of external sensors including switches, photocells, temperature sensors, inductive loops, hall effect sensors, soil probes and many more. − − Care should be taken not to exceed the allowable input voltage: − * XO-1 -0.5V to 5V − * XO-1.5 -6V to +9V − * XO-1.75 -6V to +9V − − It is a good idea, particularly on the XO-1, to put a resistor of 680 ohms in the phono plug, this increases the allowable input voltage range. − − [[image:Audio 680 ohm.jpg|center|300px]] − − ===Plotting=== − You can use save data from measure to the Sugar Journal using the Capture feature described above ([[Activities/Measure#Using|16]]). These data can then be imported into [[Activities/SimpleGraph#Graphing_Measure_data|SimpleGraph]], where they are displayed. − − [[File:SimpleGraph8.png|center|300px]] − − ===More ideas=== − You can find ideas for fun science experiments at [[Activities/TurtleArt/Using_Turtle_Art_Sensors]] and http://wiki.laptop.org/go/Measure − − ===Building sensors=== − There are detailed instructions for building sensors at http://wiki.laptop.org/go/Measure#How_to_build_low_cost_sensors − − ===Adding instruments=== − You can add new instruments to tune by modifying the instrument dictionary in config.py. − − INSTRUMENT_DICT = { − _('Guitar'): [82.4069, 110, 146.832, 195.998, 246.942, 329.628], − _('Violin'): [195.998, 293.665, 440, 659.255], − _('Viola'): [130.813, 195.998, 293.665, 440], − _('Cello'): [65.4064, 97.9989, 146.832, 220], − _('Bass'): [41.2034, 55, 73.4162, 97.9989], − _('Charango'): [329.63, 392, 440, 523.25, 659.26], − _('Ukulele'): [261.626, 329.628, 391.995, 440], − _('Sitar'): [174.614, 130.813, 195.998, 65.4064, 391.995, 261.626, 523.251], − _('Mandolin'): [195.998, 293.665, 440, 659.255], − _('Recorder'): [391.995] − } − − == Reporting problems == − Make comments/suggestions on the [[Talk:Activities/Measure]] page. − − Please file bugs at [https://bugs.sugarlabs.org/newticket?component=Measure]. − − To list all open tickets of Measure, see [https://bugs.sugarlabs.org/query?status=accepted&status=assigned&status=new&status=reopened&component=Measure]. − − [[Category:Activities]]
Migrate to GitHub
== Measure ==
Read at https://help.sugarlabs.org/measure.html
The source file has been moved to [https://github.com/godiard/help-activity/blob/master/source/measure.rst GitHub]
The sensor toolbar - measurement settings
[[File:Measure3rdtoolbar.JPG|600px|center]]