Wireless Auscultation Device for Continuous Monitoring of Heart Sounds Danielle Manley | Stephen Krammin | Mateusz Koper May 8, 2015 Biomedical Engineering Program, Lawrence Technological University, MI 48075 ABSTRACT The goal of this project was to create a wireless auscultation device. Additionally, this project looked at continuous monitoring because it provided temporal data that allowed for effective diagnosis. This would remove the need for a physician’s presence during the collection of heart sounds. We also had a goal of creating a device that could send heart sounds via Bluetooth. All of these goals were successful. By using a microphone, front end electronics, an Arduino Uno, and a Bluetooth transceiver we were able to collect heart sounds, amplify and filter them, and then send them to a Bluetooth paired device for later analysis. From that point we could look at an FFT graph to determine the frequency components of our signals and then perform additional digital filtering to remove noise. 1
Transcript
Wireless Auscultation Device for Continuous Monitoring of Heart Sounds
Danielle Manley | Stephen Krammin | Mateusz Koper
May 8, 2015
Biomedical Engineering Program, Lawrence Technological University, MI 48075
ABSTRACT
The goal of this project was to create a wireless auscultation device. Additionally, this
project looked at continuous monitoring because it provided temporal data that allowed for
effective diagnosis. This would remove the need for a physician’s presence during the collection
of heart sounds. We also had a goal of creating a device that could send heart sounds via
Bluetooth. All of these goals were successful. By using a microphone, front end electronics, an
Arduino Uno, and a Bluetooth transceiver we were able to collect heart sounds, amplify and
filter them, and then send them to a Bluetooth paired device for later analysis. From that point
we could look at an FFT graph to determine the frequency components of our signals and then
perform additional digital filtering to remove noise. After that we could playback the sounds,
which is ultimately how our device would provide clinical information for patient diagnosis.
So to summarize our project we have been able to create a wireless prototype that can
collect and send heart sounds using Bluetooth. We have also successfully created a MATLAB
program that can process and playback captured heart sounds. Due to this, we believe that our
device can compete with both mechanical and electronic stethoscopes in terms of ease of use,
sound quality, and cost.
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Table of ContentsBACKGROUND………………………………………………………………………………...................3
What is Auscultation……………………………………………………………………………………....3
TimelineThis is our timeline for the completion of this project, in terms of the second semester. We
initially began working on things in early January and finished early May.
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Informed Consent Form & Participant Information Sheet
Wireless Auscultation Device for Continuous Monitoring of Lung and Heart Sounds
Danielle ManleyStephen Krammin
Mateusz Koper
Informed Consent to Participate
Biomedical engineering students Mateusz Koper, Stephen Krammin, and Danielle Manley of the Lawrence Technological University, College of Engineering, invite you to be a part of the “Wireless Auscultation Device for Continuous Monitoring of Lung and Heart Sounds” research project. This research study looks at the audio signals that are produced by the lungs and the heart. The purpose of the study is to be able to conclude that our device can pick up and transmit body sounds as well existing methods, wirelessly. This will be done by placing a monitoring device against the chest that will receive the body sounds and then transmit them to a phone or laptop for recording and data capture. We are asking you to participate because we need a large amount of data in order to show statistical significance in our results.
If you agree to be part of the research study, you will be provided with a survey that asks you to provide us with a quick background about you, including your age, gender, and if you have any lung or heart conditions. We expect this survey to only take a couple minutes to complete.
After completion of the survey you may be asked to become a test subject for our research. You will be asked to enter your contact information at start of the survey, yet there is no guarantee you will be contacted if you provide this information. If you are not selected as a participant, our record of your contact information and identifiers will be destroyed. There is no obligation to become a research subject by filling out this form and the following survey.
Should you decide to participate further by accepting an offer to be a test subject, you should be aware of the following information regarding our research and data collection procedures, which are outlined on the following page.
Product testing with our device: (1) week
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1) We ask that each subject place the device on a few key locations of their chest 2) This test will require about a half hour of each participants time for explanation, preparation, and testing
User feedback: Survey1) Each participant will then need to provide feedback regarding comfort and any other thoughts or
opinions on their experience with the product
Subjects should understand that the device may be slightly uncomfortable to wear. All subjects are encouraged to stop testing at any time if they feel unsafe or experience discomfort of any kind.
While you may not receive any direct benefit for participating, we hope that this study will contribute to our study of the continuous monitoring of lung and heart sounds.
Researchers will be able to link your survey responses to you via your contact information, but this information will be kept protected and anonymous to everyone but the researchers. We plan to publish the results of this study, but will not include any information that would identify you.
Participating in this study is completely voluntary. Even if you decide to participate now, you may change your mind and stop at any time. You may choose to not answer an individual question or you may skip any section of the survey/interview.
Regarding compensation, please note that you will not be provided with any monetary compensation for participating in this study.
If you have questions about your rights as a research participant, please contact the Lawrence Technological University Institutional Review Board, Matthew Cole, PhD, IRB Chair, 21000 West Ten Mile Road, Southfield, MI 48075, (248) 204-3096, [email protected].
If you have read this informed consent form, understand the information contained in this informed consent form, and agree to participate in this study, please print and sign your name below, and enter today’s date. You will be offered a copy of this form to keep.
Your consent acknowledges your understanding of the risks for participating in this research. Please initial the following statement and fill out the necessary contact information below:
________“I hereby assume all risk of injury, damage and harm to myself arising from use of the Training Heel Insert, and testing of the Training Heel Insert at Lawrence Tech facilities. I also herby individually and on behalf of my heirs, executors and assignees, release and hold harmless Lawrence Tech, its officials, employees and agents and waive any right of recovery that I might have to bring a claim or a lawsuit against them for any personal injury, death or other consequences occurring to me arising out of my volunteer activities.”
__________________________________________ Participant (please print your name)
__________________________________________ ________________ Participant (please sign your name) Date
__________________________________________ ________________ Investigator’s signature Date
Wireless Auscultation Device for Continuous
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Monitoring of Lung and Heart Sounds
Danielle ManleyStephen Krammin
Mateusz Koper
Background Information Questionnaire
1) What is your age?
2) What is your gender:
3) Do you have any lung or heart conditions? If so, what are they?
Arduino Code to Read Analog Voltages
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/* ReadAnalogVoltage Reads an analog input on pin 0, converts it to voltage, and prints the result to the serial monitor. Attach the center pin of a potentiometer to pin A0, and the outside pins to +5V and ground. This example code is in the public domain. */
// the setup routine runs once when you press reset:void setup() { // initialize serial communication at 9600 bits per second: Serial.begin(9600);}
// the loop routine runs over and over again forever:void loop() { // read the input on analog pin 0: int sensorValue = analogRead(A0); // Convert the analog reading (which goes from 0 - 1023) to a voltage (0 - 5V): //float voltage = sensorValue * (5.0 / 1023.0); // print out the value you read: Serial.println(sensorValue);}
Arduino Code to Read Voltages / Send to MATLAB via USB
#include <TimerOne.h>byte end_count; // Declare variables for acquisition and sending commandschar inChar;char serial_buffer[12] = " "; float acquiredData[100]; // Initialize an array to store the readings from the analog inputconst int timer_count = 10000; // Set the timer for the interruptconst int numReadings = 100; // Set the number of readings to be taken from the analog inputint inputPin = A0; // Select analog pin to use
// ---------------------------------------void setup(){ pinMode(inputPin, INPUT); // Initialize the analog pin as an input Serial.begin(57600); // Initialize serial communication with the computer}// ----------------------------------------void loop()
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{ if (Serial.available() > 0) // If the serial port receieves an input... { doSomething(); //...run doSomething function }}// ----------------------------------------void doSomething(){ end_count = Serial.readBytesUntil('!', serial_buffer, 12); // Wait for character input inChar = serial_buffer[end_count-1]; // The character we want is the last one before the '!' switch(inChar) { case ('a'): acquire_data(); break; case ('r'): transfer_data(); break; }} // ------------------------------------------ void acquire_data(){ Timer1.attachInterrupt(getData_ISR); Timer1.initialize(timer_count); delay(1100); // Wait for data acquisition (i.e. more than 1 second)}// -----------------------------------------void getData_ISR(){ static int numberAcquired = 0; acquiredData[numberAcquired] = analogRead(inputPin); // Read the signal numberAcquired++; // Move to next data point if (numberAcquired > numReadings) { Timer1.stop(); // Stop the timer numberAcquired = 0; // Reset the data point index to zero }}// ------------------------------------------void transfer_data(){ int i; // Generic index variable for (i=0; i<numReadings; i++) // Send analog values {
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end_count = Serial.readBytesUntil('!', serial_buffer, 12); // Wait for character input Serial.println(acquiredData[i]); // Send data }}// ------------------------------------------
void setup(){ pinMode(9,OUTPUT); // This pin will pull the HC-05 key pin HIGH to switch module to AT mode digitalWrite(9,HIGH); Serial.begin(9600); Serial.println("Enter AT commands"); BTSerial.begin(38400); // HC-05 default speed in AT command }
void loop(){ if (BTSerial.available()) Serial.write(BTSerial.read()); if(Serial.available()) BTSerial.write(Serial.read()); }
Arduino Code for Real-Time Bluetooth Data Transfer
{ int voltageReading = analogRead(inputPin); Serial.println(voltageReading); delay(200); }
Arduino Code to Read Voltages / Send to MATLAB via Bluetooth
#include <SoftwareSerial.h> // Include Arduino libraries#include <TimerOne.h>byte incomingByte = 0; // Declare variables for acquisition and sending commands int AtoD_value[200]; // Initialize an array to store the readings from the analog inputint timer_count = 5000; // Set the timer for 5000 microseconds (0.005 sec or 200 Hz)int numReadings = 200; // Set the number of readings to be taken from the analog inputint inputPin = A0; // Select analog pin to useSoftwareSerial Blue(10,11); // RX, TX
// ---------------------------------------void setup(){ int i; Blue.begin(9600); // Initialize Bluetooth communication Serial.begin(9600); // Initialize serial communication with the computer pinMode(inputPin, INPUT); // Initialize the analog pin as an input for (i=0; i<numReadings; i++) { AtoD_value[i] = 0; }}// ----------------------------------------void loop(){ if (Serial.available() > 0) // If the serial port receives an input... { incomingByte = Serial.read(); // Get byte: if (incomingByte == 0) // Respond accordingly: { getValues(); Serial.println(incomingByte); } if (incomingByte == 1) {
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sendValues(); Serial.println(incomingByte); } }}// ------------------------------------------ void getValues(){ // Attach Interrupt Service Routirne (ISR) function // to acquire to data array Timer1.attachInterrupt(getData_ISR); Timer1.initialize(timer_count); delay(1100); // Wait for data acquisition (i.e. more than 1 second)}// -----------------------------------------void getData_ISR(){ static int numberAcquired = 0; AtoD_value[numberAcquired] = analogRead(inputPin); // Read the signal numberAcquired++; // Move to next data point if (numberAcquired > numReadings) { Timer1.stop(); // Stop the timer numberAcquired = 0; // Reset the data point index to zero }}// ------------------------------------------void sendValues(){ int i; // generic index variable for (i=0; i<numReadings; i++) // Send analog values { Serial.println(AtoD_value[i]); // Send data }}// ------------------------------------------
char inputChar; // Display character for acquisition and sending commands int Fs = 1000; // Set the sampling frequency in Hz
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int acquisitionTime = 10000; // Set the time for data acquisition in millisecondsint inputPin = A0; // Read data off of analog pin 0int timer_count = 1000;File myFile;
// ------------------------------------------void setup(){ Serial.begin(9600); // Initialize serial communication Serial.print("Initializing SD card..."); pinMode(inputPin, INPUT); // Initialize the analog pin as an input pinMode(10, OUTPUT); if (!SD.begin(4)) { Serial.println("initialization failed!"); return; } Serial.println("initialization done."); Serial.println("Press 0 to write voltages to SD");}// ------------------------------------------void loop(){ if (Serial.available() > 0) // If the serial port receives an input... { inputChar = Serial.read(); // Get character: if (inputChar == '0') // Respond accordingly: { myFile = SD.open("TEST.txt", FILE_WRITE); // open the file Serial.print("Writing to TEST.txt..."); getValues(); } else // If the file didn't open, print an error: { Serial.println("error opening TEST.txt"); } myFile.close(); // close the file: Serial.println("done."); } } // ------------------------------------------void getValues(){ //int timer_count = 1/(Fs*10^-6); // Set the time delay between data points in microseconds Timer1.attachInterrupt(getData); Timer1.initialize(timer_count);
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delay(acquisitionTime); // Wait for data acquisition (delay in milliseconds)}// ------------------------------------------void getData(){ static int i = 1; int numReadings = 10000;//(acquisitionTime/1000)*Fs; int voltage = analogRead(inputPin); myFile.println(voltage); i++; if (i > numReadings) { Timer1.detachInterrupt(); Timer1.stop(); i = 1; }}// ------------------------------------------
Arduino Code to Write Data to SD / Send to MATLAB via USB
#include <SPI.h> #include <SD.h>#include <TimerOne.h>byte end_count;char inChar;char serial_buffer[12] = " ";int Fs = 200; // Set the sampling frequency in Hzint acquisitionTime = 1000; // Set the time for data acquisition in millisecondsint inputPin = A0; // Read data off of analog pin 0File myFile;
// ------------------------------------------void loop() { if (Serial.available() > 0) // If the serial port receieves an input... { doSomething(); }}// ------------------------------------------void doSomething(){ end_count = Serial.readBytesUntil('!', serial_buffer, 12); // Wait for character input inChar = serial_buffer[end_count-1]; // The character we want is the last one before the '!' switch(inChar) { case ('a'): myFile = SD.open("Test.txt", FILE_WRITE); // open the file: getValues(); myFile.close(); // close the file: break; case ('r'): myFile = SD.open("Test.txt"); // open the file: transferData(); myFile.close(); // close the file: break; }} // ------------------------------------------void getValues(){ int timer_count = 1/(Fs*10^-6); // Set the time delay between data points in microseconds Timer1.attachInterrupt(getData); Timer1.initialize(timer_count); delay(acquisitionTime); // Wait for data acquisition }// ------------------------------------------void getData(){ static int i = 1; int numReadings = (acquisitionTime/1000)*Fs; int voltage = analogRead(inputPin); myFile.println(voltage); i++; if (i > numReadings) {
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Timer1.detachInterrupt(); Timer1.stop(); i = 1; }}// ------------------------------------------void transferData(){ int i; // Generic index variable int numReadings = (acquisitionTime/1000)*Fs; for (i=0; i<numReadings; i++) { int val = myFile.parseInt(); Serial.println(val); }}// ------------------------------------------
Arduino Code to Write Data to SD / Send to MATLAB via Bluetooth
byte incomingByte;int Fs = 1000; // Set the sampling frequency in Hzint acquisitionTime = 10000; // Set the time for data acquisition in millisecondsint inputPin = A0; // Read data off of analog pin 0int timer_count = 1000;SoftwareSerial Blue(2,3); // RX, TXFile myFile;
// ------------------------------------------void setup() { Blue.begin(9600); // Initialize Bluetooth communication Serial.begin(9600); // Initialize serial communication with the computer pinMode(inputPin, INPUT); // Initialize the analog pin as an input pinMode(10, OUTPUT); if (!SD.begin(4)) { return; }}
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// ------------------------------------------void loop() { if (Serial.available() > 0) // If the serial port receieves an input... { doSomething(); }}// ------------------------------------------void doSomething(){ incomingByte = Serial.read(); switch(incomingByte) { case (0): myFile = SD.open("Blue4.txt", FILE_WRITE); // open the file: getValues(); myFile.close(); // close the file: break; case (1): myFile = SD.open("Blue4.txt"); // open the file: transferData(); myFile.close(); // close the file: break; }} // ------------------------------------------void getValues(){ Timer1.attachInterrupt(getData); Timer1.initialize(timer_count); delay(acquisitionTime); // Wait for data acquisition }// ------------------------------------------void getData(){ static int i = 1; int numReadings = 10000; int voltage = analogRead(inputPin); myFile.println(voltage); i++; if (i > numReadings) { Timer1.detachInterrupt(); Timer1.stop(); i = 1;
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}}// ------------------------------------------void transferData(){ int i; // Generic index variable int numReadings = (acquisitionTime/1000)*Fs; for (i=0; i<numReadings; i++) { int val = myFile.parseInt(); Serial.println(val); }}// ------------------------------------------
MATLAB Code for Voltages Read and Sent via USB
function serial_get_data()% declare global variablesglobal serglobal the_data global arduino_deviceglobal baudglobal acquisition_time initialize();main_menu();end % ==================================== function initialize()global the_dataglobal arduino_deviceglobal baudglobal serglobal acquisition_time % Fill a data vector with zeroesacquisition_time = 1; % 1 secondthe_data = zeros(100, 1);% change these parameters for specific boardarduino_device = 'COM16';baud = 57600;% Create a serial object, then open it:ser = serial(arduino_device, 'BaudRate', baud);
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fopen(ser);end % ==================================== function main_menu();global serglobal the_data% Flag to continue loopingloop_flag = 1;% Flag to indicate if data has been acquired at least onceacquire_flag = 0;% Flag to indicate if data has been retrievedretrieve_flag = 0; while (loop_flag == 1) disp(' '); disp('Enter:'); disp(' <a> to perform data acquisition on Arduino '); disp(' <r> to retrieve data from Arduino'); disp(' <p> to plot data'); disp(' <q> to quit'); disp(' '); answer = input('> ', 's'); % Take appropriate action based on answer switch answer case 'q' % Setting loop_flag to 0 will end while % loop next time around loop_flag = 0; case 'a' % Tell Arduino to acquire and set the acquire flag Arduino_acquire(); acquire_flag =1; case 'r' % If the data has been acquired... if(acquire_flag == 1) % Tell the Arduino to send it, and store Arduino_send_and_store(); % Set the retrieve flag retrieve_flag = 1; else disp(' '); disp('No data available. Please acquire.'); disp(' '); end case 'p'
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% If the data has been retrieved... if(retrieve_flag == 1) % Plot the data plot_data(); else disp(' '); disp('No data available. Please retrieve.'); disp(' '); end endend % Clean up...disp('Done. See you next time. Thanks.');disp(' ');% Be sure to close the serial devicefclose(ser)end % ====================================
function Arduino_acquire()global serglobal acquisition_timefprintf(ser, 'a!'); pause(acquisition_time);end % ==================================== function Arduino_send_and_store()global the_dataglobal ser%% Send the send commandfprintf(ser, 'r!'); % collect the datafor i = 1:100 % Send the Arduino a ready signal fprintf(ser, 'ready!'); % Read values from serial port number = fscanf(ser, '%c'); the_data(i) = str2num(number)/204.6; % Print values to the screen as well fprintf('Got a value: %d\n', the_data(i)); end
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end % ====================================
function plot_data()global the_datax = [0:99]';plot(x, the_data)end
MATLAB Code for Real-Time Bluetooth Data Transfer
% Try-catch is to prevent Matlab from crashing when the program is finishedtry % Initialize serial portb = Bluetooth('HC-05', 1);fopen(b);b.ReadAsyncMode = 'continuous'; % Various variablesnumberOfDatas = 200;data = zeros(1, numberOfDatas);i = 1; % Main graph figurefigure(1);hold on;title('Incoming Data from External Device');xlabel('Data Number');ylabel('Analog Voltage'); % Start asynchronous readingreadasync(b); while(i<=numberOfDatas) % Get the data from the serial object data(i) = fscanf(b, '%d')/204.6; %fprintf('Got a value: %d\n', data(i)); % Plot the data figure(1); plot(i, data(i), 'm*'); % Ensure there are always 10 tick marks on the graph if(i>100) xlim([i-100 i]);
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set(gca,'xtick',[i-100 i-90 i-80 i-70 i-60 i-50 i-40 i-30 i-20 i-10 i]) end % Draw and flush drawnow; %Increment the counter i=i+1; end % Give the external device some time…pause(3); return; catch % Some of these crash the program – it depends. The serial port is left% open, which is not good. stopasync(b);fclose(b); %delete(b);%clear b; fprintf(1, 'Sorry, you''re going to have to close out of Matlab to close the serial port\n');returnend
MATLAB Code for Voltages Read and Sent via Bluetooth
function Auscultation_bluetooth()% declare global variablesglobal bglobal the_data global acquisition_timeinitialize();main_menu();end
% ==================================== function initialize()global bglobal the_dataglobal acquisition_time% Fill a data vector with zeros
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acquisition_time = 1; % 1 secondthe_data = zeros(200, 1);b = Bluetooth('HC-05',1);fopen(b);end % ==================================== function main_menu()global b% Flag to continue loopingloop_flag = 1;% Flag to indicate if data has been acquired at least onceacquire_flag = 0;% Flag to indicate if data has been retrievedretrieve_flag = 0; while (loop_flag == 1) disp(' '); disp('Enter:'); disp(' <0> to perform data acquisition on Arduino '); disp(' <1> to retrieve data from Arduino'); disp(' <p> to plot data'); disp(' <q> to quit'); disp(' '); answer = input('> ', 's'); % Take appropriate action based on answer switch answer case 'q' % Setting loop_flag to 0 will end while % loop next time around loop_flag = 0; case '0' % Tell Arduino to acquire and set the acquire flag Arduino_acquire(); acquire_flag = 1; case '1' % If the data has been acquired... if(acquire_flag == 1) % Tell the Arduino to send it, and store Arduino_send_and_store(); % Set the retrieve flag retrieve_flag = 1; else disp(' '); disp('No data available. Please acquire.'); disp(' ');
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end case 'p' % If the data has been retrieved... if(retrieve_flag == 1) % Plot the data plot_data(); else disp(' '); disp('No data available. Please retrieve.'); disp(' '); end endend % Clean up...disp('Done. See you next time. Thanks.');disp(' ');% Be sure to close the serial devicefclose(b);delete(b);end % ==================================== % Tell the Arduino to acquire the data.% Sending a "0" to the Arduino directs it% to perform the acquisition.%% After sending the command, the function waite% to allow the Arduino time to acquire the data function Arduino_acquire()global bglobal acquisition_timefwrite(b, 0); pause(acquisition_time);end % ==================================== % Tell the Arduino to send the data.% Sending a "1" to the Arduino initiates% the send sequence. function Arduino_send_and_store()global the_dataglobal b
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%% Send the send commandfwrite(b, 1);%% collect the datafor i = 1:200 the_data(i) = fscanf(b, '%d')/204.6; % Print values to the screen as well fprintf('Got a value: %d\n', the_data(i)); endend % ==================================== % Create x values and plot the % current data. The user may need to manually% close the plot window for the program to enter% back into the main loop. function plot_data()global the_datax = [0:199]';plot(x, the_data)end
MATLAB Code for Voltages Read from SD and Sent via USB
function SD_Card_USB()initialize();main_menu();end % ==================================== function initialize()global acquisition_timeglobal numberReadingsglobal dataglobal arduino_deviceglobal baudglobal ser acquisition_time = 1; % 1 second% Fill a data vector with zerosnumberReadings = 200;data = zeros(numberReadings, 1);
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% Change these parameters for specific boardarduino_device = 'COM16';baud = 9600;% Create a serial object, then open it:ser = serial(arduino_device, 'BaudRate', baud);fopen(ser);end % ==================================== function main_menu()global ser% Flag to continue loopingloop_flag = 1;% Flag to indicate if data has been acquired at least onceacquire_flag = 0;% Flag to indicate if data has been retrievedretrieve_flag = 0; while (loop_flag == 1) disp(' '); disp('Enter:'); disp(' <a> to perform data acquisition on Arduino '); disp(' <r> to retrieve data from Arduino'); disp(' <p> to plot data'); disp(' <q> to quit'); disp(' '); answer = input('> ', 's'); % Take appropriate action based on answer switch answer case 'q' % Setting loop_flag to 0 will end while % loop next time around loop_flag = 0; case 'a' % Tell Arduino to acquire and set the acquire flag Arduino_acquire(); acquire_flag = 1; case 'r' % If the data has been acquired... if(acquire_flag == 1) % Tell the Arduino to send it, and store Arduino_send_and_store(); % Set the retrieve flag retrieve_flag = 1; else disp(' ');
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disp('No data available. Please acquire.'); disp(' '); end case 'p' % If the data has been retrieved... if(retrieve_flag == 1) % Plot the data plot_data(); else disp(' '); disp('No data available. Please retrieve.'); disp(' '); end endend % Clean up...disp('Done. See you next time. Thanks.');disp(' ');% Be sure to close the serial devicefclose(ser);end % ==================================== function Arduino_acquire()global serglobal acquisition_time fprintf(ser, 'a!'); pause(acquisition_time);disp(' ');disp('Data acquired successfully');end % ==================================== function Arduino_send_and_store()global dataglobal serglobal numberReadings % Tell the Arduino to send datafprintf(ser, 'r!'); % collect the datafor i = 1 : numberReadings
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number = fscanf(ser, '%c'); data(i) = str2double(number)/204.6; % Display the data if desired %fprintf('Voltage = %d\n', data(i)); enddisp(' ');disp('Data sent successfully');end % ==================================== function plot_data()global datax = (1:200)';plot(x, data)end
MATLAB Code for Voltages Read from SD and Sent via Bluetooth
function SD_Card_Bluetooth()initialize();main_menu();end % ==================================== function initialize()global acquisitionTimeglobal Fsglobal dataglobal b acquisitionTime = 10; % In number of secondsFs = 1000; % Sampling frequencydata = zeros(Fs*acquisitionTime, 1); % Fill a data vector with zeros % Create a serial object, then open it:b = Bluetooth('HC-05',1);fopen(b);end % ==================================== function main_menu()global b% Flag to continue looping
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loop_flag = 1;% Flag to indicate if data has been acquired at least onceacquire_flag = 0;% Flag to indicate if data has been retrievedretrieve_flag = 0; while (loop_flag == 1) disp(' '); disp('Enter:'); disp(' <0> to perform data acquisition on Arduino '); disp(' <1> to retrieve data from Arduino'); disp(' <p> to plot data'); disp(' <q> to quit'); disp(' '); answer = input('> ', 's'); % Take appropriate action based on answer switch answer case 'q' % Setting loop_flag to 0 will end while % loop next time around loop_flag = 0; case '0' % Tell Arduino to acquire and set the acquire flag Arduino_acquire(); acquire_flag = 1; case '1' % If the data has been acquired... if(acquire_flag == 1) % Tell the Arduino to send it, and store Arduino_send_and_store(); % Set the retrieve flag retrieve_flag = 1; else disp(' '); disp('No data available. Please acquire.'); disp(' '); end case 'p' % If the data has been retrieved... if(retrieve_flag == 1) % Plot the data plot_data(); else disp(' '); disp('No data available. Please retrieve.'); disp(' '); end
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endend % Clean up...disp('Done. See you next time. Thanks.');disp(' ');% Be sure to close the serial devicefclose(b);end % ==================================== function Arduino_acquire()global bglobal acquisitionTime fwrite(b, 0); pause(acquisitionTime); % Wait for the data to be acquireddisp(' ');disp('Data acquired successfully');end % ==================================== function Arduino_send_and_store()global bglobal Fsglobal acquisitionTimeglobal data % Tell the Arduino to send datafwrite(b, 1); % collect the datafor i = 1 : (Fs*acquisitionTime) number = fscanf(b,'%c'); data(i) = str2double(number);%/204.6; % Print values to the screen if desired fprintf('Voltage = %d\n', data(i)); enddisp(' ');disp('Data sent successfully');end % ==================================== function plot_data()
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global dataglobal Fsglobal acquisitionTime x = (1:Fs*acquisitionTime)';%figure;plot(x, data)%axis([0 acquisitionTime 0 5])%xlabel('Time (seconds)')%ylabel('Analog Voltage')%title('Acquired Data from Arduino')end
