serial begin(115200) doesnt work for me

Projects Interfacing w/ Software on the Computer
1

so here is what i am trying to do:
i have a doppler sensor, from that i want to read a data with my uno and send it via usb cable to my computer to process it with matlab or python.

this is my arduino code:

int in = A0; // the pin i am using to analog read
int v=0; // the voltage value i am trying to send to matlab/python

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
}

void loop() {
    v = analogRead(in);
    Serial.println(v); 
}

this simple code is how i am trying to communicate with my pc. if you guys have a better aproch, please let me know.

this is my code in matlab to read from uno:

clear;clc;
ser = serialport("com3",9600); % arduino doesnt send anything with 115200 so i didnt update this part. it is normally 115200
configureTerminator(ser,"CR");

n=10000; % number of samples i am trying to read

v=zeros(n,1);

readline(ser); % since i am getting the first reading a ???, i try to use this so the first reading goes
                   % vein
disp("ready");
pause(2);
disp("go");
tic()
for i=1:n
    v(i)=readline(ser);
end
rt=toc() % so-called runtime (it runs for about 50 secs to collect 10k samples with 9600 baud rate
v = v.* 0.004887585532746823; % 5/1023

so guys,

  1. i cant read data with baudrate of 115200 and i see some forum topics that i normally should be able to run uno with baud rate of 115200.

  2. when i try to use baud rate of 9600 it works normally, but i gate 10k samples in about 50 seconds thus my sampling frequency is abut 200, i am trying to increase this number.

so guys,
i am in need of your help, you can either offer me a better version of coding, or a better understanding..

thanks to you all for support

edit:

for example, i found this code online:

void setup()
{
  Serial.begin(115200);
  pinMode(A0, INPUT);
}

void loop()
{
  long t0, t;

  t0 = micros();
  for(int i=0; i<1000; i++) {
    analogRead(A0);
  }
  t = micros()-t0;  // calculate elapsed time

  Serial.print("Time per sample: ");
  Serial.println((float)t/1000);
  Serial.print("Frequency: ");
  Serial.println((float)1000*1000000/t);
  Serial.println();
  delay(2000);
}

and it simply doesnt work when i upload it to my uno. serial monitor only shows ????
thanks

2

emrep:
and it simply doesnt work when i upload it to my uno. serial monitor only shows ????

Have you changed the baud rate in the Serial Monitor to match the Uno?

...R

3

i didnt know there was a baud rate at serial monitor. this is embrassing. but thanks for the help (y)

4

emrep:
i didnt know there was a baud rate at serial monitor. this is embrassing. but thanks for the help (y)

Been there. Done that. Welcome to the club :slight_smile:

...R