Guitar Tuning Project - Revision history

Mat Kotowsky: Guitar Tunning Project moved to Guitar Tuning Project: misspelling

2009-03-18T22:48:05Z

2008-12-08T16:17:21Z

Voltage Comparator

2008-12-08T00:45:15Z

DC motor Drive

2008-12-08T00:17:05Z

DC motor Drive

2008-12-08T00:16:06Z

DC motor Drive

2008-12-08T00:11:15Z

2008-12-08T00:01:47Z

Band-pass filter (Using LMF100)

2008-12-07T23:12:11Z

Programmable Function generator (Using AD9833)

2008-12-07T23:01:07Z

Programmable Function generator (Using AD9833)

2008-12-07T22:34:42Z

Programmable Function generator (Using AD9833)

@@ Line 40: / Line 40: @@
 [[Image:GTTP_Rectify and filter.jpg]]
-===Voltage Comparator===
+===Voltage Comparator with hysteresis band===
 The function of this circuit is to convert the sine wave signal into a square wave signal while keeping the same frequency. In order to prevent the wrong turn caused by noise, 2 thresholds are set in the circuits, namely up threshold and down threshold. The circuit is shown in following figure:

@@ Line 93: / Line 93: @@
 ===DC motor Drive ===
 We have 6 DC motors (Faulhaber 141:1 gear motor) to be driven. L293 is used here containing 2 full H-bridges,therefore 3 LM293 are used to drive 6 DC motors. The circuits diagram is shown as the figure. We used 6 '''enable''' pins to address each full H-bridges,
-''' Direction''' and '''PWM''' signals are connected to each H-bridges.
+''' Direction''' and '''PWM''' signals are connected to each H-bridge.
+[[Image:GTTP_DC Drive.jpg]]
 ==Software coding ==

@@ Line 92: / Line 92: @@
 ===DC motor Drive ===
-We have 6 DC motors (Faulhaber 141:1 gear motor) to be driven. LM293 is used here containing 2 full H-bridges,therefore 3 LM293 are used to drive 6 DC motors. The circuits diagram is shown as the figure. We used 6 '''enable''' pins to address each full H-bridges,
+We have 6 DC motors (Faulhaber 141:1 gear motor) to be driven. L293 is used here containing 2 full H-bridges,therefore 3 LM293 are used to drive 6 DC motors. The circuits diagram is shown as the figure. We used 6 '''enable''' pins to address each full H-bridges,
 ''' Direction''' and '''PWM''' signals are connected to each H-bridges.

@@ Line 92: / Line 92: @@
 ===DC motor Drive ===
+We have 6 DC motors (Faulhaber 141:1 gear motor) to be driven. LM293 is used here containing 2 full H-bridges,therefore 3 LM293 are used to drive 6 DC motors. The circuits diagram is shown as the figure. We used 6 '''enable''' pins to address each full H-bridges,
+''' Direction''' and '''PWM''' signals are connected to each H-bridges.
 ==Software coding ==

@@ Line 90: / Line 90: @@
 LMF100 is used here.
+===DC motor Drive ===
 ==Software coding ==

← Older revision	Revision as of 22:48, 18 March 2009
(No difference)

@@ Line 87: / Line 87: @@
 ===Band-pass filter (Using LMF100) ===
+Because the output signal from the microphone and preamplifier contains environmental noise, more importantly, the harmonics of string vibration, so we need a band-filter to remove the harmonics, only let the signal with the fundamental frequency pass.
+LMF100 is used here.
 ==Software coding ==

@@ Line 73: / Line 73: @@
    conv_freq = (int32)(freq*13.4218);// 2^28/CLOCK = (2^28)/(20*10^6) = 13.4218
-Then, separate the conv_freq into two 16 bits bits, MSB (most significant bits) and LSB (least significant bits)
+Then, separate the conv_freq into two 16 bits bits, msb (most significant bits) and lsb (least significant bits)
-   LSB= (int 16)(conv_freq)&(0b0011111111111111);  (Get the lowest 14 bits of conv_freq)
+   lsb= (int 16)(conv_freq)&(0b0011111111111111);  (Get the lowest 14 bits of conv_freq)
-   MSB= (int 16)(conv_freq>>14)(0b0011111111111111); (get the 14 most significant bits out of 28 bits conv_freq)
+   msb= (int 16)(conv_freq>>14)(0b0011111111111111); (get the 14 most significant bits out of 28 bits conv_freq)
   spi_xfer(0x2168);       // reset, tell it to expect two writes-*
-   spi_xfer(0x4000 | lsb); // lsb in freq0
+  spi_xfer(0x4000 | lsb); // lsb in freq0
-   spi_xfer(0x4000 | msb); // msb in freq0
+  spi_xfer(0x4000 | msb); // msb in freq0
-   spi_xfer(0xB000);       // zero in phase0
+  spi_xfer(0xB000);       // zero in phase0
-   spi_xfer(0x0068);       // unreset, set up write
+  spi_xfer(0x0068);       // unreset, set up write
 ===Band-pass filter (Using LMF100) ===

@@ Line 65: / Line 65: @@
 '''FSYNC''': Active Low Control Input. This is the frame synchronization signal for the input data. When FSYNC is taken low, the internal logic is informed that a new word is being loaded into the device.
+The series timing is shown in following figure. When FSYNC is low, one bit is transmitted at each falling edge of SCLK.
+[[Image:GTTP_AD9833 Timing.jpg]]
 First, we have to convert the frequency ('''freq''') into a value that AD 9833 wants named '''conv_freq'''