NOTE: We do not use of the second method in embedded system software writing. Because it would have to execute more instructions to perform the same operation with a temporary variable.
Swapping using a temporary variable
#include <stdio.h>
#include <stdlib.h>
int main(void) {
int a = 10;
int b = 3;
int temp = 0;
printf("Before Swapping");
printf("\na = %d\tb = %d\n",a,b);
temp = a;
a = b;
b = temp;
printf("After Swapping");
printf("\na = %d\tb = %d\n",a,b);
return EXIT_SUCCESS;
}
Swapping without using a temporary variable
#include <stdio.h>
#include <stdlib.h>
int main(void) {
int a = 10;
int b = 3;
int temp = 0;
printf("Before Swapping");
printf("\na = %d\tb = %d\n",a,b);
a = a - b;
b = a + b;
a = b - a;
printf("After Swapping");
printf("\na = %d\tb = %d\n",a,b);
return 1;
}
Swapping using pointers
When the memory size is very limited we prefer to do this.
#include <stdio.h>
#include <stdlib.h>
int main(void) {
int a = 10;
int b = 3;
int temp;
int *x , *y;
printf("Before Swapping");
printf("\na = %d\tb = %d\n",a,b);
x = &a;
y = &b;
temp = *x;
*x = *y;
*y = temp;
printf("After Swapping");
printf("\na = %d\tb = %d\n",a,b);
return 1;
}
The serial console is written in a python programming language. The GUI is made using the Tkinter library and the serial interface functions are provided by the pyserial library.
you can install pyserial from command prompt(windows)/terminal(linux)
Python Code
from tkinter import *
from tkinter import ttk
import serial
import serial.tools.list_ports
import datetime
import threading
import multiprocessing
import os
#for printing debugging messages in console
dbg = 0
gRoot = Tk()
#gRoot.geometry("480x280")
gRoot.title("Serial Console")
sty = ttk.Style()
sty.theme_use("alt")
gRoot.columnconfigure(0,weight=1)
gRoot.rowconfigure(0,weight=1)
#sty.configure("gframe.TFrame",background="white")
gFrame = ttk.LabelFrame(gRoot,text="Connection Setting",padding=10)
gFrame.grid(column=1,row=1, sticky=(W,E))
#Frame for COM messages
gFrame21 = ttk.Frame(gRoot,padding=10)
gFrame21.grid(column=2,row=1, sticky=(W))
#gRoot.resizable(0,0)
for x in range(10):
gFrame.columnconfigure(x,weight = x)
gFrame.rowconfigure(x,weight = x)
label1=ttk.Label(gFrame, text = "Serial Console")
label1.grid(column=2,row=0)
gFrame.rowconfigure(0,weight=2)
sty.configure("label2.TLabel",borderwidth=4,relief="ridge",foreground="red",ipadx=10)
label2=ttk.Label(gFrame,sty="label2.TLabel", text = "Select Com Port")
label2.grid(column=1,row=1, sticky = (N,E,W,S))
"""
Com Port List
"""
#Start
ports = serial.tools.list_ports.comports()
com_port_list = [com[0] for com in ports]
com_port_list.insert(0,"Select an Option")
if dbg == 1:
print(com_port_list)
#END
com_value_inside = StringVar()
baud_value_inside = StringVar()
baud_menu = ttk.OptionMenu(gFrame,baud_value_inside,"select baud rate","9600",
'19200','28800','38400','57600','76800',
'115200','128000','153600','230400','256000','460800','921600')
baud_menu.grid(column=3, row=1, sticky = (E))
def com_port_list_update():
global ports
global com_port_list
ports = serial.tools.list_ports.comports()
com_port_list = [com[0] for com in ports]
com_port_list.insert(0,"Select an Option")
if dbg == 1:
print(com_port_list)
com_menu = ttk.OptionMenu(gFrame,com_value_inside,*com_port_list)
com_menu.grid(column=2, row=1, sticky = (E))
#Frame for the COM LIST
gRoot_com_list = Toplevel(gRoot)
x = gRoot.winfo_x()
y = gRoot.winfo_y()
gRoot_com_list.geometry("+%d+%d" %(x+200,y+200))
gFrame01 = ttk.Frame(gRoot_com_list,padding=10)
gFrame01.grid(column=0,row=1, sticky=(W))
#Create a horizontal scrollbar
scrollbar = ttk.Scrollbar(gFrame01, orient= 'horizontal')
scrollbar.grid(column=1,row=2, sticky=W+E)
Lb1 = Listbox(gFrame01, xscrollcommand = 1, width = 50, font= ('Helvetica 8 bold'))
counter = 0;
for x in ports:
Lb1.insert(counter, str(x))
#print (counter)
counter += 1
Lb1.grid(column=1,row=1, sticky=W+E)
Lb1.config(xscrollcommand= scrollbar.set)
#Configure the scrollbar
scrollbar.config(command= Lb1.xview)
def serial_print():
global serFlag
global ser
global counter1
x =""
#print("Task 1 assigned to thread: {}".format(threading.current_thread().name))
#print("ID of process running task 1: {}".format(os.getpid()))
if(serFlag):
if(ser.in_waiting>0):
#
try:
x = ser.read(ser.in_waiting)
#x = ser.readline(ser.in_waiting)
#x = ser.read_until(expected='\n', size=ser.in_waiting)
#print(x)
y = str(counter1)+": "+str(datetime.datetime.now())+" -> "+str(x.decode())
Lb2.insert(counter1, str(y))
Lb2.see("end")
#print (counter1)
counter1 += 1
#gFrame.after(100,serial_print)
except:
pass
ser.flush()
gFrame.after(100,serial_print)
ser = serial.Serial()
serFlag = 0
def serial_connect(com_port,baud_rate):
global ser
ser.baudrate = baud_rate
ser.port = com_port
ser.timeout = 1
ser._xonxoff=1
ser.bytesize=serial.EIGHTBITS
ser.parity=serial.PARITY_NONE
ser.stopbits=serial.STOPBITS_ONE
ser.open()
global serFlag
serFlag = 1
t1 = threading.Thread(target = serial_print, args = (), daemon=1)
t1.start()
#t1.join()
"""
P1 = multiprocessing.Process(target = serial_print, args=())
P1.start()
P1.join()
"""
#serial_print()
counter1 = 0;
def serial_close():
global ser
global serFlag
serFlag = 0
ser.close()
def submit_value():
if dbg == 1:
print("selected option: {}".format(com_value_inside.get()))
print(" Baud Rate {}".format(baud_value_inside.get()))
serial_connect(com_value_inside.get(),baud_value_inside.get())
Lb2 = Listbox(gFrame21, width = 100, xscrollcommand = 1)
Lb2.grid(column=1, row = 1, sticky = W+E)
Sb2 = ttk.Scrollbar(gFrame21,orient = 'vertical')
Sb2.config(command=Lb2.yview)
Sb2.grid(column = 2,row =1, sticky=N+S)
Sb2v = ttk.Scrollbar(gFrame21,orient = 'horizontal')
Sb2v.grid(column = 1,row =2, sticky=W+E)
Sb2v.config(command = Lb2.xview)
Lb2.configure(xscrollcommand = Sb2v.set, yscrollcommand = Sb2.set)
def clear_listbox():
Lb2.delete(0,END)
subBtn = ttk.Button(gFrame,text="submit",command = submit_value)
subBtn.grid(column=4,row=1, sticky = (E))
RefreshBtn = ttk.Button(gFrame,text="Get List",command = com_port_list_update)
RefreshBtn.grid(column=2,row=2, sticky = (E))
closeBtn = ttk.Button(gFrame,text="Disconnect",command = serial_close)
closeBtn.grid(column=4,row=2, sticky = (E))
clearBtn = ttk.Button(gFrame,text="Clear Messages",command = clear_listbox)
clearBtn.grid(column=3,row=2, sticky = (E))
"""
#Add a Listbox Widget
listbox = Listbox(win, width= 350, font= ('Helvetica 15 bold'))
listbox.pack(side= LEFT, fill= BOTH)
#Add values to the Listbox
for values in range(1,101):
listbox.insert(END, values)
"""
def donothing():
filewin = Toplevel(gRoot)
button = Button(filewin, text="Do nothing button")
button.pack()
def About_me():
filewin = Toplevel(gRoot)
Label1 = Label(filewin, text = "EXASUB.COM").pack()
button = Button(filewin, text="Quit", command = filewin.destroy)
button.pack()
menubar = Menu(gRoot)
filemenu = Menu(menubar, tearoff=0)
filemenu.add_command(label="New", command=donothing)
filemenu.add_command(label="Open", command=donothing)
filemenu.add_command(label="Save", command=donothing)
filemenu.add_command(label="Save as...", command=donothing)
filemenu.add_command(label="Close", command=donothing)
filemenu.add_separator()
filemenu.add_command(label="Exit", command=gRoot.quit)
menubar.add_cascade(label="File", menu=filemenu)
editmenu = Menu(menubar, tearoff=0)
editmenu.add_command(label="Undo", command=donothing)
editmenu.add_separator()
editmenu.add_command(label="Cut", command=donothing)
editmenu.add_command(label="Copy", command=donothing)
editmenu.add_command(label="Paste", command=donothing)
editmenu.add_command(label="Delete", command=donothing)
editmenu.add_command(label="Select All", command=donothing)
menubar.add_cascade(label="Edit", menu=editmenu)
helpmenu = Menu(menubar, tearoff=0)
helpmenu.add_command(label="Help Index", command=donothing)
helpmenu.add_command(label="About...", command=donothing)
menubar.add_cascade(label="Help", menu=helpmenu)
menubar.add_command(label = "EXASUB.com", command = About_me)
menubar.add_separator()
menubar.add_command(label = "Quit", command = gRoot.destroy)
gRoot.config(menu=menubar)
gRoot.mainloop()
Python’s functionality can be extended with scripts that are made to do different tasks. They are sometimes super easy to work with and can perform a myriad of tasks with just a few lines of code.
To run a python script. You have to open python in either the command prompt or its IDLE.
We can make use of pyinstaller module. Which will take your script and add all the dependencies and create a standalone executable file which you can use just like any other software.
To install pyinstaller
open your command prompt and execute the following code
pip install pyinstaller
This will install pyinstaller .
After doing it. Browse into your script folder.
pyinstaller --onefile your-python-script.py
If you run the above line it will create a self containing executable file.
You can also have a directory in which all the dependency files are placed along with the executable file.
