Read Arduino keypad input until specific character in python

Projects Programming
1

I used arduino mega2560 development board. I want to give number as input by 4*4 keypad. Then in serial communication I want to read that input until specific character.

My Arduino code is already working correctly
This is my Arduino code

#include <Keypad.h>

const byte numRows= 4; //number of rows on the keypad
const byte numCols= 4; //number of columns on the keypad

//keymap defines the key pressed according to the row and columns just as appears on the keypad
char keymap[numRows][numCols]= 
{
{'1', '2', '3', 'A'}, 
{'4', '5', '6', 'B'}, 
{'7', '8', '9', 'C'},
{'*', '0', '#', 'D'}
};

//Code that shows the the keypad connections to the arduino terminals
byte rowPins[numRows] = {11,10,9,8}; //Rows 0 to 3
byte colPins[numCols]= {7,6,5,4}; //Columns 0 to 3

//initializes an instance of the Keypad class
Keypad myKeypad= Keypad(makeKeymap(keymap), rowPins, colPins, numRows, numCols);

int i=0;
int a[20];
int number=0;
int j=0;
void setup()
{
Serial.begin(9600);
}

void loop()
{

  char keypressed = myKeypad.getKey();
  if (keypressed != NO_KEY)
  {
 i++;
    if(keypressed != 'A')
      {
              a[i]=keypressed-48;

          }   

    else
    {
        for(int j=1;j<i;j++)
        {
          Serial.print(a[j]);         
        }
          Serial.print('A');
        i=0;

}
}
}

It give these type of serial output
123A (A is my specific number)

then I want to read this serial output within a while loop from python

this is my python code

from __future__ import print_function    
import pypyodbc
import serial
import time
import datetime
s = serial.Serial('COM31', 9600)
time.sleep(2)


while (1==1):


        code = s.readline()// Read keyboard input
        k = str(code)
        L= k.index('A')
        m= k[:L]
        print(m)

But python is not display any thing

Any one know what is the problem here........

2

Any one know what is the problem here........

One problem is that you are asking about a problem with Python in the Arduino programming forum.

3

This Python - Arduino demo may give you some ideas.

I don't think your Python code is allowing time for the Arduino to reset when Python opens the serial port.

...R