Mozart's Right Hand - Revision history

Mat Kotowsky: /* Component Data Sheets */

2009-03-27T19:31:12Z

Component Data Sheets

Mat Kotowsky: /* Left Side */

2009-03-20T06:45:13Z

Left Side

Mat Kotowsky: /* Function Generator */

2009-03-20T06:44:25Z

Function Generator

Mat Kotowsky: /* Play Enable */

2009-03-20T06:42:43Z

Play Enable

Mat Kotowsky: /* Left Side */

2009-03-20T03:22:31Z

Left Side

Mat Kotowsky: /* LCD */

2009-03-20T03:21:05Z

LCD

Mat Kotowsky: /* Effect of Centripetal Acceleration */

2009-03-20T03:15:07Z

Effect of Centripetal Acceleration

Mat Kotowsky at 02:59, 20 March 2009

2009-03-20T02:59:11Z

Mat Kotowsky: /* Creating the Signal */

2009-03-20T02:48:21Z

Creating the Signal

Mat Kotowsky: /* Further Reading and References */

2009-03-20T02:44:57Z

@@ Line 316: / Line 316: @@
 ==Component Data Sheets==
-*[[http://www.analog.com/en/mems-and-sensors/imems-accelerometers/adxl320/products/product.html AD9833 data sheet]
+*[http://www.analog.com/en/mems-and-sensors/imems-accelerometers/adxl320/products/product.html AD9833 data sheet]
 *[http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en010297 Microchip PIC18F4520]
 *[http://www.datasheetcatalog.com/datasheets_pdf/T/D/A/2/TDA2040H.shtml TDA-2040 20-watt amplifier]

@@ Line 94: / Line 94: @@
 ===Left Side===
-[[Image:mrh_box_left.JPG|left|thumb|200px|Left side of the desktop box]][[Image:mrh_box_plate.JPG|right|thumb|200px|Power supply reinforcement plate]]
+[[Image:mrh_box_left.JPG|left|thumb|200px|Left side of the desktop box]]
+[[Image:mrh_box_plate.JPG|right|thumb|200px|Power connector reinforcement plate]]
 On the left side of the box is a 5-pin circular DIN power connector that mates with the desktop power supply.  Because a significant amount of force is required to mate the power connector with the power supply, the connector is secured to the enclosure with a custom-machined metal plate.  Also on the left side of the box is the 10-pin rectangular plug that accepts the ribbon cable from the glove.  This header is keyed so that the ribbon cable cannot be inserted backwards.  It is secured to the enclosure with epoxy.

@@ Line 63: / Line 63: @@
 ===Function Generator===
 [[Image:mrh_function_generator.JPG|center|thumb|200px|[http://www.analog.com/en/rfif-components/direct-digital-synthesis-dds/ad9833/products/product.html AD9833] programmable function generator with carrier board custom-designed in [http://lims.mech.northwestern.edu/ Northwestern University's LIMS lab]|right]]
-The [http://www.analog.com/en/rfif-components/direct-digital-synthesis-dds/ad9833/products/product.html AD9833] function generator is a small chip that can generate square waves, sine waves, and triangle waves of varying frequencies.  It communicates using a 16-bit version of [http://en.wikipedia.org/wiki/Serial_Peripheral_Interface_Bus SPI].  Our code is a re-use of the code from the [[Guitar_Tunning_Project#Programmable_Function_generator_.28Using_AD9833.29| Guitar Tuning Project]].  Mozart's Right Hand uses a sine wave to drive its speaker.  When the AD9833 is configured to produce a sine wave output, instead of oscillating about zero, the sine wave oscillates around 0.3 volts with an amplitude of 0.3 volts.  The [http://lims.mech.northwestern.edu/ LIMS]-designed AD9833 carrier board uses an [http://www.national.com/mpf/LM/LM6132.html LM6132] operational amplifier to line-shift and amplify the signal such that it oscillates about 0 volts with an amplitude of 2 volts.  This signal is not strong enough to generate a suitable tone, so it is passed through another amplifier, as described below, before going to the speaker.
+The [http://www.analog.com/en/rfif-components/direct-digital-synthesis-dds/ad9833/products/product.html AD9833] function generator is a small chip that can generate square waves, sine waves, and triangle waves of varying frequencies.  It communicates using a 16-bit version of [http://en.wikipedia.org/wiki/Serial_Peripheral_Interface_Bus SPI].  The code to operate the function generator is a re-use of the code from the [[Guitar_Tunning_Project#Programmable_Function_generator_.28Using_AD9833.29| Guitar Tuning Project]].  Mozart's Right Hand uses a sine wave to drive its speaker.  When the AD9833 is configured to produce a sine wave output, instead of oscillating about zero, the sine wave oscillates around 0.3 volts with an amplitude of 0.3 volts.  The [http://lims.mech.northwestern.edu/ LIMS]-designed AD9833 carrier board uses an [http://www.national.com/mpf/LM/LM6132.html LM6132] operational amplifier to line-shift and amplify the signal such that it oscillates about 0 volts with an amplitude of 2 volts.  This signal is not strong enough to generate a suitable tone, so it is passed through another amplifier, as described below, before going to the speaker.
 The LIMS carrier board also includes various components that provide for signal conditioning, power regulation, and reverse- and short-current protection.

@@ Line 51: / Line 51: @@
 ===Play Enable===
 [[Image:mrh_glove_contacts.JPG|center|thumb|200px|Play enable contacts on glove|right]]
-The Play Enable functionality is implemented with two thin strips of aluminum that are shaped into a semicircle and attached to the thumb and index fingertips of the glove with double-stick tape.  Sections of hookup wire are soldered to the contacts and then run through the fingers of the glove to the accelerometer where one is attached to ground and the other runs through the ribbon cable to be connected to a digital input pin on the microcontroller.
+The Play Enable functionality is implemented with two thin strips of aluminum that are shaped into semicircles and attached to the thumb and index fingertips of the glove with double-stick tape. Sections of hookup wire are soldered to these fingertip contacts and run through the fingers of the glove to the accelerometer. There, one fingertip contact is attached to ground and the other runs through the ribbon cable to be connected to a digital input pin on the microcontroller.
 <br clear=all>

@@ Line 95: / Line 95: @@
 ===Left Side===
 [[Image:mrh_box_left.JPG|left|thumb|200px|Left side of the desktop box]][[Image:mrh_box_plate.JPG|right|thumb|200px|Power supply reinforcement plate]]
-On the left side of the box are a 5-pin circular DIN power connector that mates with the desktop power supply.  Because a significant amount of force is required to mate the power connector with the power supply, the connector is secured to the enclosure with a custom-machined metal plate.  Also on the left side of the box is the 10-pin rectangular plug that accepts the ribbon cable from the glove.  This header is keyed so that the ribbon cable cannot be inserted backwards.  It is secured to the enclosure with epoxy.
+On the left side of the box is a 5-pin circular DIN power connector that mates with the desktop power supply.  Because a significant amount of force is required to mate the power connector with the power supply, the connector is secured to the enclosure with a custom-machined metal plate.  Also on the left side of the box is the 10-pin rectangular plug that accepts the ribbon cable from the glove.  This header is keyed so that the ribbon cable cannot be inserted backwards.  It is secured to the enclosure with epoxy.
 <br clear=all>

@@ Line 79: / Line 79: @@
 ===LCD===
 [[Image:mrh_lcd.JPG|right|thumb|300px|The LCD|right]]
-Mozart's Right Hand makes use of a 16 by 2 character LCD with a blue backlight.  This LCD is HD44780 compatible, as described in [[C_Example:_Parallel_Interfacing_with_LCDs|LCD interfacing]] article on the Mechatronics Wiki.  During operation of Mozart's Right Hand, the LCD will, at all times, display the note that corresponds to the current orientation of the glove.  If the finger contacts are not touched together, the LCD will also display "Muted" to indicate that no sound should be coming out of the speaker.  When the finger contacts are touched together, the word "Muted" disappears and the speaker will play the note indicated.
+Mozart's Right Hand makes use of a 16 by 2 character LCD with a blue backlight.  This LCD is HD44780 compatible, as described in the [[C_Example:_Parallel_Interfacing_with_LCDs|LCD interfacing]] article on the Mechatronics Wiki.  During operation of Mozart's Right Hand, the LCD will, at all times, display the note that corresponds to the current orientation of the glove.  If the finger contacts are not touched together, the LCD will also display "Muted" to indicate that no sound should be coming out of the speaker.  When the finger contacts are touched together, the word "Muted" disappears and the speaker will play the note indicated.
 <br clear=all>

@@ Line 29: / Line 29: @@
 During typical use, the user's hand remains stationary and the only effect on the pitch is the glove's orientation with respect to gravity.  It is possible, however, that the user will want to play a note while simultaneously moving his hand.  The speaker will play different tones as the user moves his hand through the different orientations.  During this type of playing, the acceleration measured by the accelerometer is not only due to gravity but due to the effect of [http://en.wikipedia.org/wiki/Centripetal_force centripetal force] caused by the hands rotation about the user's wrist, elbow, or shoulder.  If one assumes that such motion is uniform and circular about its center, then the acceleration measured during motion is a superposition of the acceleration due to gravity and the acceleration toward the center of rotation: [[Image:mrh_aequalsv2overr.jpg]].
-The average length of a human hand is approximate 180mm (from [http://en.wikipedia.org/wiki/Hand http://en.wikipedia.org/wiki/Hand]), so the distance between the accelerometer and the wrist is about half of that: 90mm.  If the fastest a user moved his hand from straight down to straight up is one second, its total distance traveled would be one half of the circumference of a circle with a radius of 90mm: approximately 280mm, for a velocity of about 280mm per second.  Therefore, the acceleration towards the wrist would be approximately 0.9 meters per second squared.  This is lest than one tenth of a g, so a user would not experience a significant change in note pitch due to centripetal acceleration while rotating at the wrist.
+The average length of a human hand is approximately 180mm (from [http://en.wikipedia.org/wiki/Hand http://en.wikipedia.org/wiki/Hand]), so the distance between the accelerometer and the wrist is about half of that: 90mm.  If the fastest a user moved his hand from straight down to straight up is one second, its total distance traveled would be one half of the circumference of a circle with a radius of 90mm: approximately 280mm, for a velocity of about 280mm per second.  Therefore, the acceleration towards the wrist would be approximately 0.9 meters per second squared.  This is less than one tenth of a g, so a user would not experience a significant change in note pitch due to centripetal acceleration while rotating at the wrist.
 The same calculation could be carried out for playing Mozart's Right Hand by rotating through the elbow or the shoulder.

@@ Line 3: / Line 3: @@
 [[Image:mrh_box.JPG|center|thumb|300px|Mozart's Right Hand box|left]]
 [[Image:mrh_playing.JPG|center|thumb|550px|Mozart's Right Hand in action|right]]
+<br clear=all>
-<BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR>
 ==The Team==
@@ Line 10: / Line 10: @@
 *Sean Wood ( seanwood2010 at u dot northwestern dot edu ), Mechanical Engineering Junior
 *Mat Kotowsky (kotowsky at northwestern dot edu), Civil Engineering Graduate Student
-<BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR>
+<br clear=all>
 =Theory of Operation=
@@ Line 22: / Line 23: @@
 For both the X and Y axes, the actual values used to determine the thresholds between notes were determined empirically.  They appear in the code below.
-<BR><BR><BR><BR><BR><BR><BR><BR><BR>
+<br clear=all>
 ==Effect of Centripetal Acceleration==
@@ Line 43: / Line 45: @@
 ===Accelerometer===
 [[Image:mrh_accel.JPG|center|thumb|200px|[http://www.analog.com/en/mems-and-sensors/imems-accelerometers/adxl320/products/product.html ADXL-320] [http://en.wikipedia.org/wiki/MEMS MEMS] accelerometer|right]]
-The accelerometer is an [http://www.analog.com/en/mems-and-sensors/imems-accelerometers/adxl320/products/product.html ADXL-320] [http://en.wikipedia.org/wiki/MEMS MEMS] accelerometer configured for dual-axis use.  Though it has a range of +/-5g, it is only used in the +/-1g range.  The accelerometer has pins V+, GND, X, Y, and a test pin.  The test pin, though connected to the ribbon cable, is not used.  The X and Y pins provide ratiometric analog output.  V+ is connected to a 5 VDC output coming from a regulator inside of the desktop box.  The GND pin is connected to one end of the Play Enable switch closure and also to the digital ground inside of the desktop box.  The accelerometer is sewn to the top of the glove using the signal wires through the mounting holes on the carrier board.<BR><BR><BR><BR><BR><BR><BR><BR><BR>
+The accelerometer is an [http://www.analog.com/en/mems-and-sensors/imems-accelerometers/adxl320/products/product.html ADXL-320] [http://en.wikipedia.org/wiki/MEMS MEMS] accelerometer configured for dual-axis use.  Though it has a range of +/-5g, it is only used in the +/-1g range.  The accelerometer has pins V+, GND, X, Y, and a test pin.  The test pin, though connected to the ribbon cable, is not used.  The X and Y pins provide ratiometric analog output.  V+ is connected to a 5 VDC output coming from a regulator inside of the desktop box.  The GND pin is connected to one end of the Play Enable switch closure and also to the digital ground inside of the desktop box.  The accelerometer is sewn to the top of the glove using the signal wires through the mounting holes on the carrier board.
+<br clear=all>
 ===Play Enable===
 [[Image:mrh_glove_contacts.JPG|center|thumb|200px|Play enable contacts on glove|right]]
 The Play Enable functionality is implemented with two thin strips of aluminum that are shaped into a semicircle and attached to the thumb and index fingertips of the glove with double-stick tape.  Sections of hookup wire are soldered to the contacts and then run through the fingers of the glove to the accelerometer where one is attached to ground and the other runs through the ribbon cable to be connected to a digital input pin on the microcontroller.
-<BR><BR><BR><BR><BR><BR><BR><BR><BR>
+<br clear=all>
 ==Desktop Box==
@@ Line 61: / Line 66: @@
 The LIMS carrier board also includes various components that provide for signal conditioning, power regulation, and reverse- and short-current protection.
-<BR><BR><BR><BR><BR><BR><BR><BR><BR><br>
+<br clear=all>
 ===Amplifier and Speaker===
@@ Line 68: / Line 74: @@
 In the wiring diagram pictured to the right, <math>V_i</math> represents the input signal to the amplifier -- in this case, the output of the function generator after it has been passed through a 100K-ohm knob potentiometer for volume control.  <math>+V_s</math> and <math>-V_s</math> represent the +12 and -12 volt input from the DC power supply.  <math>R_L</math> represents the speaker.  Note that in this diagram, a capacitor with a white side is polarized with white denoting the positive terminal.
-<BR><BR><BR><BR><BR><BR><BR><BR>
+<br clear=all>
 ===LCD===
 [[Image:mrh_lcd.JPG|right|thumb|300px|The LCD|right]]
 Mozart's Right Hand makes use of a 16 by 2 character LCD with a blue backlight.  This LCD is HD44780 compatible, as described in [[C_Example:_Parallel_Interfacing_with_LCDs|LCD interfacing]] article on the Mechatronics Wiki.  During operation of Mozart's Right Hand, the LCD will, at all times, display the note that corresponds to the current orientation of the glove.  If the finger contacts are not touched together, the LCD will also display "Muted" to indicate that no sound should be coming out of the speaker.  When the finger contacts are touched together, the word "Muted" disappears and the speaker will play the note indicated.
-<BR><BR><BR><BR><BR>
+<br clear=all>
 ===Enclosure===
@@ Line 82: / Line 90: @@
 [[Image:mrh_box_top.JPG|center|thumb|200px|Top of the desktop box|right]]
 On the top of the box, there is a large rocker switch for power.  This DPDT switch will break the supply of +12 and -12 volts coming from the power supply.  Also on the top of the box is a numbered knob to control volume.  This knob is a 100K-ohm potentiometer that scales the output of the function generator as it is going into the audio amplifier.  The knob is secured to the enclosure with epoxy.
-<br><br><br><br><br><br><br><br><br>
+<br clear=all>
 ===Left Side===
 [[Image:mrh_box_left.JPG|left|thumb|200px|Left side of the desktop box]][[Image:mrh_box_plate.JPG|right|thumb|200px|Power supply reinforcement plate]]
 On the left side of the box are a 5-pin circular DIN power connector that mates with the desktop power supply.  Because a significant amount of force is required to mate the power connector with the power supply, the connector is secured to the enclosure with a custom-machined metal plate.  Also on the left side of the box is the 10-pin rectangular plug that accepts the ribbon cable from the glove.  This header is keyed so that the ribbon cable cannot be inserted backwards.  It is secured to the enclosure with epoxy.
-<br><br><br><br><br><br><br><br><br><br><br><br>
+<br clear=all>
 =Software=

@@ Line 260: / Line 260: @@
 }
 </pre>
 ==Playing Notes==

@@ Line 295: / Line 295: @@
 =Further Reading and References=
+==The Project==
 *Full Mozart's Right Hand Code: [[Media:mrh_code.c| mrh_code.c]]
-*[http://en.wikipedia.org/wiki/Diatonic_scale Notes and frequencies of the diatonic scale]
 *[http://www.youtube.com/watch?v=vec-W4QeHQU YouTube video of Mozart's Right Hand in action]
+==Theory References==
+*[http://en.wikipedia.org/wiki/Diatonic_scale Notes and frequencies of the diatonic scale]
 *[http://en.wikipedia.org/wiki/Centripetal_force Wikipedia: Centripetal Force]
 *[http://en.wikipedia.org/wiki/Hand Wikipedia: The Hand]
 *[http://en.wikipedia.org/wiki/Serial_Peripheral_Interface_Bus Wikipedia: Serial Peripheral Interface (SPI) bus)]
-*[http://www.analog.com/en/mems-and-sensors/imems-accelerometers/adxl320/products/product.html AD9833 data sheet]
+==Component Data Sheets==
-*The [http://lims.mech.northwestern.edu/ LIMS Laboratory] at [http://www.northwestern.edu Northwestern University]
+*[[http://www.analog.com/en/mems-and-sensors/imems-accelerometers/adxl320/products/product.html AD9833 data sheet]
 *[http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en010297 Microchip PIC18F4520]
-*[[Guitar Tuning Project]]
 *[http://www.datasheetcatalog.com/datasheets_pdf/T/D/A/2/TDA2040H.shtml TDA-2040 20-watt amplifier]
 *[[C_Example:_Parallel_Interfacing_with_LCDs|LCD interfacing]] article on the Mechatronics Wiki
+==Mechatronics References==
+*The [http://lims.mech.northwestern.edu/ LIMS Laboratory] at [http://www.northwestern.edu Northwestern University]
+*[[Guitar Tuning Project]]