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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.+ − − − − '''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]] − − ==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. The selected input type - Sound (AC voltage), resistance or DC voltage − − 5. The time scale − − 6. Freeze the display − − 7. Capture sample now - saves an image of the wave in the Journal − − 8. Stop - exits the Activity − − 9. Mute - mute/unmute channel − − 10. Invert - invert the display − − 11. Use these sliders to control the sensitivity − − 12. The settings that are selected − − − − − The sensor toolbar - measurement settings − − 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. Time base/frequency - graphs the signal vs. time or graphs amplitude vs. frequency − − 17. Sample interval - a text file 'Measure Log' is saved to the journal, it contains one sample per interval − − 18. Starts/stops saving a text file 'Measure Log' with measured values as readable text − − 19. Trigger - synchronise the sample period to the waveform so that the sample will start on a rising edge or falling edge − − − [[File:Measure3rdtoolbar.JPG|600px|center]] − − 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 − − 22. Frequency entry - enter a frequency to mark − − 23. Show/hide tuning mark − − 24. Show/hide harmonics − − 25. Play a note − − 26. Measured note − − [[image:Measure-tuning.JPG|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 − − ==Sharing== − This Activity does not currently support sharing. − − ==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 http://wiki.sugarlabs.org/go/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. − − [[Category: Activity]]
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 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.
[[File:Measure2ndtoolbar.JPG|600px|center]]