Logs

March 12, 2024

1.use function generator (waveform generator) to input 4MHz signal to test microphone to see if it works.

March 14, 2024

1.Connect the waveform generator to the oscilloscope and set it up to check the waveform.
2. In the experimental setup, a microphone with four terminals (GND, CLK, Data, and Vdd) is soldered onto a circuit board. The positive terminal of a waveform generator is connected to the CLK (input) terminal of the microphone to input a 4 MHz square wave with an amplitude of 5V. The Data (output) terminal of the microphone is connected to the positive terminal of an oscilloscope to observe the waveform output by the microphone in response to the CLK input. The Vdd terminal of the microphone is connected to the 5V supply (pin 1) of a Raspberry Pi 2 Model B. The negative terminals of the microphone, waveform generator, and oscilloscope are connected to the GND of the Raspberry Pi to provide a common ground.
The setup and output is below.

Fig.1 Waveform Generator

Fig.2 Oscilloscope

Fig.3 Setup

3.Connect the sync output of the waveform generator to an input channel of the oscilloscope, using the waveform as a trigger signal to capture and stabilize the waveform output from the microphone.

March 21, 2024

1.Replace the digital microphone with a microphone that outputs an analog signal, which has 3 amplifiers.
2.Connect two microphones to two channels of the oscilloscope and change the time division resolution to distinguish the time delay of the sound source at a certain distance, so as to determine its one-dimensional position.
3.It is necessary to understand the two-dimensional and three-dimensional theoretical calculation to adjust the parameters to complete the measurement.

March 26, 2024

1. Done four experiments. Expt.1/2: Sound source position: 200cm. Expt.3: Sound source position: 150cm. Expt.4: Sound source position: 100cm. Output .dat file and analyze through matlab.
2. Analyze data. Plot the waveform diagram of the sound. Calculate and plot the cross-correlation function of signal 1＆1, signal 2＆2， signal 1＆2.
Outlook: 1. Multiply the time interval with peak position to get time difference
2. Using FFT as a comparison (TDOA method, same theory not necessary)

March 28, 2024

Modify the code with another method that first calculate the FFT and then inverse it finally output an angle, but the angle will have an imaginary part. Try to derive the expression of the sound source position and change code further. Haven't adjust the time scale so that no new data update.

April 2, 2024

Detail of experiments:

Fig.1 Experiment detail

Exp.1: 0cm

Time scale: 2.00ms/div
0402_C2Trace00000 (Trigger)
0402_C3Trace00000
Condition: L = 2m, x = 0m
The waveform is complete.

Fig.2 Result of Exp.1_1

Result:
delta_t = 0.0045751s
x_pos = 0.22223m

Time scale: 2.00ms/div
0402_C2Trace00001 (Trigger)
0402_C3Trace00001
Condition: L = 2m, x = 0m
The waveform is complete.

Fig.3 Result of Exp.1_2

Result:
delta_t = 0.0051612s
x_pos = 0.12259m

Exp.2: 50cm

Time scale: 2.00ms/div
0402_C2Trace00002 (Trigger)
0402_C3Trace00002
Condition: L = 2m, x = 0.5m
The waveform is complete.

Fig.4 Result of Exp.2

Result:
delta_t = 0.0008545s
x_pos = 0.85474m

Exp.3: 100cm

Time scale: 2.00ms/div
0402_C2Trace00003 (Trigger)
0402_C3Trace00003
Condition: L = 2m, x = 1m
The waveform is complete.

Fig.5 Result of Exp.3

Result:
delta_t = 0.00105s
x_pos = 0.8215m

April 9, 2024

Detail of experiments:

Fig.1 Experiment detail

Exp.1

Time scale: 500ms/div
0409_C4Trace00000 (Trigger)
0409_C2Trace00004
Condition: L = 3.83m, x = 0m

Fig.2 Result of Exp.1

Result: x_pos = -1.1787m

Exp.2

Time scale: 200ms/div
0409_C4Trace00001 (Trigger)
0409_C2Trace00005
Condition: L = 3.83m, x = 0m

Fig.3 Result of Exp.2

Result: x_pos = -1.1787m

Exp.3

Time scale: 200ms/div
0409_C4Trace00002 (Trigger)
0409_C2Trace00006
Condition: L = 3.83m, x = 0.4m

Fig.4 Result of Exp.3

Result: x_pos = 1.0405m

Exp.4

Time scale: 500ms/div
0409_C4Trace00003 (Trigger)
0409_C2Trace00007
Condition: L = 3.83m, x = 0.4m

Fig.5 Result of Exp.4

Result: x_pos = 1.0405m

Exp.5

Time scale: 200ms/div
0409_2_C4Trace000012 (Trigger)
0409_2_C2Trace00008
Condition: L = 3.82m, x = 3m

Fig.6 Result of Exp.5

Result: x_pos = 2.9739m

Exp.6

Time scale: 500ms/div
0409_2_C4Trace000013 (Trigger)
0409_2_C2Trace00009
Condition: L = 3.82m, x = 3m

Fig.7 Result of Exp.6

Result: x_pos = 2.9739m

Exp.7

Time scale: 200ms/div
0409_2_C4Trace000014 (Trigger)
0409_2_C2Trace00010
Condition: L = 3.82m, x = 3.82m

Fig.8 Result of Exp.7

Result: x_pos = 3.4398m

Exp.8

Time scale: 500ms/div
0409_2_C4Trace000015 (Trigger)
0409_2_C2Trace00011
Condition: L = 3.82m, x = 3.82m

Fig.9 Result of Exp.8

Result: x_pos = 3.4398m

April 18, 2024

Detail of experiments:

Fig.1 Experiment detail

Exp.1

0418_C1Trace00000 (Trigger)
0418_C2Trace00013
Condition: L = 0m, x = 0m

Fig.2 Result of Exp.1

Result: x_pos = 0.002m

Sound source: clap

Detail of experiments:

Fig.1 Experiment detail

Exp.1: 0cm

Time scale: 200ms/div
0422_C2Trace00021 (Trigger)
0422_C4Trace00015
Condition: L = 2m, x = 0m
The waveform is complete.

Fig.2 Result of Exp.1

Result:
delta_t = 0.0033s
x_pos = 0.4372m

Exp.2: 50cm

Time scale: 200ms/div
0422_C2Trace00014 (Trigger)
0422_C4Trace00008
Condition: L = 2m, x = 0.5m
The waveform is not complete because votage diversion is too large.

Fig.3 Result of Exp.2_1

Result:
delta_t = 0.0028s
x_pos = 0.5268m

Time scale: 200ms/div
0422_C2Trace00019 (Trigger)
0422_C4Trace00013
Condition: L = 2m, x = 0.5m
The waveform is complete.

Fig.4 Result of Exp.2_2

Result:
delta_t = 0.0040s
x_pos = 0.3118m

Exp.3: 100cm

Time scale: 200ms/div
0422_C2Trace00016 (Trigger)
0422_C4Trace00010
Condition: L = 2m, x = 1m
The waveform is complete.

Fig.5 Result of Exp.3_1

Result:
delta_t = 0.0101s
x_pos = -0.7191m
Here set ch_0 as C2 and ch_1 as C4

Time scale: 50ms/div
0422_C2Trace00017 (Trigger)
0422_C4Trace00011
Condition: L = 2m, x = 1m
The waveform is complete.

Fig.6 Result of Exp.3_2

Result:
delta_t = 3.0000e-06s
x_pos = 0.9995m
Here set ch_0 as C2 and ch_1 as C4

Time scale: 5ms/div
0422_C2Trace00018 (Trigger)
0422_C4Trace00012
Condition: L = 2m, x = 1m
The waveform is complete.

Fig.7 Result of Exp.3_3

Result:
delta_t = 4.1000e-06s
x_pos = 0.9993m
Here set ch_0 as C2 and ch_1 as C4

Exp.4: 150cm

Time scale: 200ms/div
0422_C2Trace00015 (Trigger)
0422_C4Trace00009
Condition: L = 2m, x = 1.5m
The waveform is not complete because the votage division is too large.

Fig.8 Result of Exp.4_1

Result:
delta_t = -0.0034s
x_pos = 1.5772m
Here set ch_0 as C2 and ch_1 as C4

Time scale: 200ms/div
0422_C2Trace00020 (Trigger)
0422_C4Trace00014
Condition: L = 2m, x = 1.5m
The waveform is complete.

Fig.9 Result of Exp.4_2

Result:
delta_t = -0.0028s
x_pos = 1.4778m

Exp.5: 200cm

Time scale: 200ms/div
0422_C2Trace00022 (Trigger)
0422_C4Trace00016
Condition: L = 2m, x = 2m
The waveform is complete.

Fig.10 Result of Exp.5

Result:
delta_t = -0.0101s
x_pos = 2.7207m

Sound source: Hello

Detail of experiments:

Fig.1 Experiment detail

Exp.1: 50cm

Time scale: 200ms/div
0422_C2Trace00023 (Trigger)
0422_C4Trace00017
Condition: L = 2m, x = 0.5m
The waveform is complete.

Fig.2 Result of Exp.1

Result:
delta_t = 0.0027s
x_pos = 0.5325m

Exp.2: 150cm

Time scale: 200ms/div
0422_C2Trace00024 (Trigger)
0422_C4Trace00018
Condition: L = 2m, x = 1.5m
The waveform is complete.

Fig.3 Result of Exp.2

Result:
delta_t = -0.0030s
x_pos = 1.5112m

Sound source: 'a'

Detail of experiments:

Fig.1 Experiment detail

Exp.1: 50cm

Time scale: 200ms/div
0422_C2Trace00025 (Trigger)
0422_C4Trace00019
Condition: L = 2m, x = 0.5m
The waveform is complete.

Fig.2 Result of Exp.1_1

Result:
delta_t = 0.0027s
x_pos = 0.5342m

Time scale: 5ms/div
0422_C2Trace00027 (Trigger)
0422_C4Trace00021
Condition: L = 2m, x = 0.5m
The waveform is complete.

Fig.3 Result of Exp.1_2

Result:
delta_t = 0.0027s
x_pos = 0.5345m

Exp.2: 150cm

Time scale: 200ms/div
0422_C2Trace00026 (Trigger)
0422_C4Trace00020
Condition: L = 2m, x = 1.5m
The waveform is complete.

Fig.4 Result of Exp.2_1

Result:
delta_t = -0.0030s
x_pos = 1.5052m

Time scale: 5ms/div
0422_C2Trace00028 (Trigger)
0422_C4Trace00022
Condition: L = 2m, x = 1.5m
The waveform is complete.

Fig.5 Result of Exp.2_2

Result:
delta_t = -0.0030s
x_pos = 1.5079m

April 24, 2024

Detail of experiments:

Exp.1: 0cm

Time scale: 200ms/div
0424_C2Trace00029 (Trigger)
0424_C4Trace00023
Condition: L = 2m, x = 0m
The waveform is complete.

Result:
delta_t = 0.008608s
x_pos = -0.46336m

Exp.2: 200cm

Time scale: 200ms/div
0424_C2Trace00030 (Trigger)
0424_C4Trace00024
Condition: L = 2m, x = 2m
The waveform is complete.

Result:
delta_t = -0.0055572s
x_pos = 1.9447m

Detail of experiments:

Exp.1: -50cm

Time scale: 200ms/div
0424_C2Trace00031 (Trigger)
0424_C4Trace00025
Condition: L = 2m, x = -0.5m
The waveform is complete.

Result:
delta_t = 0.0056889s
x_pos = 0.03289m

Exp.2: 0cm

Time scale: 200ms/div
0424_C2Trace00032 (Trigger)
0424_C4Trace00026
Condition: L = 2m, x = 0m
The waveform is complete.

Result:
delta_t = 0.0074461s
x_pos = -0.26584m

Exp.3: 50cm

Time scale: 200ms/div
0424_C2Trace00033 (Trigger)
0424_C4Trace00027
Condition: L = 2m, x = 0.5m
The waveform is complete.

Result:
delta_t = 0.002868s
x_pos = 0.51244m

Exp.4: 100cm

Time scale: 200ms/div
0424_C2Trace00034 (Trigger)
0424_C4Trace00028
Condition: L = 2m, x = 1m
The waveform is complete.

Result:
delta_t = -0.00052826s
x_pos = 1.0898m

Exp.5: 150cm

Time scale: 200ms/div
0424_C2Trace00035 (Trigger)
0424_C4Trace00029
Condition: L = 2m, x = 1.5m
The waveform is complete.

Result:
delta_t = -0.0016308s
x_pos = 1.2772m

Exp.6: 200cm

Time scale: 200ms/div
0424_C2Trace00036 (Trigger)
0424_C4Trace00030
Condition: L = 2m, x = 2m
The waveform is complete.

Result:
delta_t = -0.0053853s
x_pos = 1.9155m

Exp.7: 250cm

Time scale: 200ms/div
0424_C2Trace00037 (Trigger)
0424_C4Trace00031
Condition: L = 2m, x = 2.5m
The waveform is complete.

Result:
delta_t = -0.000027986
x_pos = 1.974m

April 25, 2024

Detail of experiments:

Exp.1: 0cm

Time scale: 200ms/div
0424_C2Trace00038 (Trigger)
0424_C4Trace00032
Condition: L = 2m, x = 0m
The waveform is complete.

Result:
delta_t = 0.000027986s
x_pos = 1.0048m

Detail of experiments:

Exp.1: 0cm

Time scale: 200ms/div
0424_C2Trace00039 (Trigger)
0424_C4Trace00033
Condition: L = 2m, x = 0m
The waveform is complete.

Result:
delta_t = 0.0055856s
x_pos = 0.050451m

Exp.2: 150cm

Time scale: 200ms/div
0424_C2Trace00040 (Trigger)
0424_C4Trace00034
Condition: L = 2m, x = 1.5m
The waveform is complete.

Result:
delta_t = -0.0028833s
x_pos = 1.4902m