I have used a load cell. Arduino is sending the load perfectly. When the load sensed by arduino crossess some value I want to send a simple signal to matlab. Then a MATLAB should capture the image. If someone has already worked on it please share how you have done it!.
You could use the MATLAB Support Package for Arduino or plain old serial communication. The former is pretty straightforward; see the documentation. Below is a simple example of how the latter would work.
Arduino:
void setup() {
Serial.begin(9600);
}
void loop() {
int load = getLoad();
if (Serial.available()) {
Serial.println(load);
}
}
MATLAB:
% Connect to Arduino
s = serial('COM1', 'Baudrate', 9600, 'Parity', 'none', 'Databits', 8, 'Stopbits', 1);
fopen(s);
set(s, 'Timeout', 2000, 'Flowcontrol', 'none');
s.ReadAsyncMode = 'continuous';
% Read data from Arduino
load = fscanf(s, '%d');
% Close connection when done
fclose(s);
Check out the following resources for more details:
"Arduino Serial Data Acquisition" by Ye Cheng on MATLAB Central File Exchange
"Arduino and Matlab: let them talk using serial communication!" by gianluca88 on Instructables
"How To Send Data From The Arduino To MATLAB" by Miguel on AllAboutEE
"How can I communicate from Arduino to MATLAB" by Bill Nace on Arduino Stack Exchange
"Getting Started with Serial I/O" in the MATLAB Documentation
"Write and Read Data" in the MATLAB Documentation
matlabarduino.org
Related
I am currently using a Tenney Environmental Chamber which uses a Watlow F4 temperature controller to read out the temperature of the chamber. On the back of the Tenney Chamber is a 25 pin connector labelled for Watlow modbus communication. I connected to this terminal using a 25-pin-to-serial-232 adapter and a serial-232-to-usb cable. According to Watlow, to communicate with the temperature controller you must use the modbus RTU protocol. I am trying to read register 100, which is specified by Watlow as getting the actual chamber temperature.
This is very similar to another question that was asked here (Matlab serial Communication with Watlow F4 via Modbus RTU), and when I formatted my code like this it also did not work, so it has me thinking that maybe it has something to do with the 25-pin-to-serial-to-usb connection, but I'm really not sure.
Here is my code:
%create object connected to COM10
s = serial('COM10');
set(s, 'InputBufferSize', 3000);
%open object
fopen(s);
set(s, 'BaudRate', 9600);
set(s, 'Terminator', 'CR');
set(s, 'Timeout', 100);
%format request
request3= uint8(hex2dec(['01'; '03'; '00'; '64'; '00'; '01'; 'C5'; 'D5']))%FROM WATLOW EXAMPLE ONLINE: http://www.testequity.com/documents/chambers/Modbus_Packet.pdf
%write request to modbus
fwrite(s, request3);
%read reply from modbus
outdec3 = fread(s)
However, when I run this code this is the response I get:
Warning: Unsuccessful read: The specified amount of data was not returned within the Timeout period.
Am I formatting my request incorrectly? Or setting up the serial object incorrectly? Any help that can be provided would be greatly appreciated.
I am attempting to communicate from my Simblee Rfduino to Matlab, with the following Arduino code:
char testing[] = {1,2,3,4,5,6,7,8,'\0'};
void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
pinMode(6,OUTPUT);
}
void loop() {
// put your main code here, to run repeatedly:
digitalWrite(6,LOW);
Serial.flush();
testing(EMG);
Serial.flush();
digitalWrite(6,HIGH);
}
In Python I am able to correctly read in the 1-8 in the correct order consistently.
However in Matlab it continuously changes order with no consistency, with the following code:
function serial()
global ser
ser = serial('COM5', 'BaudRate', 9600, 'FlowControl', 'hardware');
fopen(ser);
end
function serial_callback(~, ~)
global ser
time = tic;
fread(ser,1) % pull in data from serial port
toc(time);
end
I think there could be some issue in the Serial buffer.
Could you please provide some guidance as to how to consistently get Matlab to read in the data in order? Have others been able to get Matlab to reliably read from a serial port?
Thank you!
You could set the FlowControl to software (xOn and xOff flags). Hardware is only possible if you have the "hardware ressources".
The input buffer of matlab usually works with fifo principle.
After fopen() you have to wait for one second. Because some microcontrollers (like arduino uno ...) restarts after initialization of the uart interface.
--> pause(1);
I am trying to send data from MATLAB to ARDUINO using the following code for arduino and the second one for the matlab. Both code work fine and when i press 1 led lights up and when press 2 led become off. But actually what i am trying to do is when matlab run code it automatically send 1 to arduino and the led become on. i have tried may changes but cant able to do. when iam trying to run the third code (given below) the arduino status led blink that show it receive some thing but my actual led which is connected to pin 13 still off.
int ledPin=13;
int matlabData;
void setup()
{
pinMode(ledPin,OUTPUT);
Serial.begin(9600);
}
void loop()
{
if(Serial.available()>0) // if there is data to read
{
matlabData=Serial.read(); // read data
if(matlabData==1)
digitalWrite(ledPin,HIGH); // turn light on
else if(matlabData==2)
digitalWrite(ledPin,LOW); // turn light off
}
}
(MATLAB)
1.
clear all
2.clc
3.
4.answer=1; % this is where we'll store the user's answer
5.arduino=serial('COM4','BaudRate',9600); % create serial communication object on port COM4
6.
7.fopen(arduino); % initiate arduino communication
8.
9.while answer
10. fprintf(arduino,'%s',char(answer)); % send answer variable content to arduino
11. answer=input('Enter led value 1 or 2 (1=ON, 2=OFF, 0=EXIT PROGRAM): '); % ask user to enter value for variable answer
12.end
13.
14.fclose(arduino); % end communication with arduino
(MY edit code)
1.
clear all
2.clc
3.
4.answer=1; % this is where we'll store the user's answer
5.arduino=serial('COM4','BaudRate',9600); % create serial communication object on port COM4
6.
7.fopen(arduino); % initiate arduino communication
8.
9.%while answer
10. fprintf(arduino,'%s',char(answer)); % send answer variable content to arduino
11. answer='1'%('Enter led value 1 or 2 (1=ON, 2=OFF, 0=EXIT PROGRAM): '); % ask user to enter value for variable answer
12.%end
13.
14.fclose(arduino); % end communication with arduino
The difference is the following:
answer = input('bla')
yields an answer that is a number, i.e. answer is of type double. In your third case, you wrote answer='1' which is a char, so in fact, the variable answer is different in both cases. Try and change the code in the third part to this here:
answer = 1;
or change the fprintf command to
fprintf(arduino, '%s', str2num(answer));
I'm working on MATLAB, I want to connect only a LED & resistor to a serial port.
When a specific action happens in my program, the LED must turn on.
What I did but nothing had happened:
S = serial( 'com1' );
fid = fopen( s ); # ... 've checked the s vs. S ?
You should be able to control the DTR and RTS lines (on DB-9 connectors on pins 4 and 7, respectively) from MATLAB. According to the reference, serial port objects have the properties DataTerminalReady and RequestToSend, which can be toggled. For example,
S = serial('com1');
for ii = 1:5
set(S, 'RequestToSend', 'on');
pause(1)
set(S, 'RequestToSend', 'off');
pause(1)
end
will flash an LED connected to the RTS pin five times.
I have seen already a few articles about this topic, but most of these were from 3-4 years ago and I have to believe someone has done this before. Does anyone know if there is a way to have a MATLAB program that will listen on a specified port number. I am trying to transmit information to MATLAB over a local network, or potentially internet, and have MATLAB do stuff with it? Any suggestions?
My other option is just to send everything to an SQL server, and then have MATLAB poll this server. I however was concerned about the speed of this because MATLAB needs to be spitting out stuff in "real-time" or as close to as possible.
Note information will be taken from an iPhone and transmitted over Wi-Fi
I would use a language which is interfaced through Matlab, such as C over mex-files or Java.
This is my example. Android user sends a file name and the file to matlab TCP server. Then, matlab TCP server receives a line which is file name and file data.
t = tcpip('0.0.0.0', 8000, 'NetworkRole', 'Server');
set(t, 'InputBufferSize', 900000);
fprintf('waiting for client');
fopen(t);
pause(1);
fprintf('client connected');
fid = fopen('temp','w+');
file_name = fgetl(t);
% read first line
while (get(t, 'BytesAvailable') > 0 )
pause(2);
t.BytesAvailable
data = fread(t, t.BytesAvailable);
pause(2);
fwrite(fid, data);
end
copyfile('temp',['../../data/' file_name]);
fclose(t);
fclose(fid);