Create a Simple 4-20 mA converter with Python and Tkinter: A Beginner’s Guide

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Here’s an example program in Python using the Tkinter library to create a simple 4-20 mA converter

import tkinter as tk

class ProcessToMilliampereConverter:
    def __init__(self, master):
        self.master = master
        master.title("Process to Milliampere Converter")

        # Create input widgets
        self.input_label = tk.Label(master, text="Input Type:")
        self.input_label.grid(row=0, column=0, padx=5, pady=5)
        self.input_var = tk.StringVar(value="Process")
        self.input_process = tk.Radiobutton(master, text="Process", variable=self.input_var, value="Process")
        self.input_current = tk.Radiobutton(master, text="Milliampere (mA)", variable=self.input_var, value="Milliampere")
        self.input_process.grid(row=1, column=0, padx=5, pady=5)
        self.input_current.grid(row=2, column=0, padx=5, pady=5)

        self.range_label = tk.Label(master, text="Range:")
        self.range_label.grid(row=0, column=1, padx=5, pady=5)
        self.range_min_label = tk.Label(master, text="Min:")
        self.range_min_label.grid(row=1, column=1, padx=5, pady=5)
        self.range_min_entry = tk.Entry(master)
        self.range_min_entry.grid(row=1, column=2, padx=5, pady=5)
        self.range_max_label = tk.Label(master, text="Max:")
        self.range_max_label.grid(row=2, column=1, padx=5, pady=5)
        self.range_max_entry = tk.Entry(master)
        self.range_max_entry.grid(row=2, column=2, padx=5, pady=5)

        self.input_value_label = tk.Label(master, text="Value:")
        self.input_value_label.grid(row=3, column=0, padx=5, pady=5)
        self.input_value_entry = tk.Entry(master)
        self.input_value_entry.grid(row=3, column=1, columnspan=2, padx=5, pady=5)

        self.convert_button = tk.Button(master, text="Convert", command=self.convert)
        self.convert_button.grid(row=4, column=0, columnspan=3, padx=5, pady=10)

        # Create output widgets
        self.output_label = tk.Label(master, text="Output:")
        self.output_label.grid(row=5, column=0, padx=5, pady=5)
        self.output_var = tk.StringVar(value="")
        self.output_entry = tk.Entry(master, textvariable=self.output_var, state="readonly")
        self.output_entry.grid(row=5, column=1, columnspan=2, padx=5, pady=5)

    def convert(self):
        # Get input type and range values
        input_type = self.input_var.get()
        range_min = float(self.range_min_entry.get())
        range_max = float(self.range_max_entry.get())

        # Convert input value to milliampere signal or process value
        if input_type == "Process":
            process_value = float(self.input_value_entry.get())
            milliampere_signal = self.process_to_milliampere(process_value, range_min, range_max)
            self.output_var.set(f"{milliampere_signal:.5f} milliampere")
        elif input_type == "Milliampere":
            milliampere_signal = float(self.input_value_entry.get())
            process_value = self.milliampere_to_process(milliampere_signal, range_min, range_max)
            self.output_var.set(f"{process_value:.5f} process value")

    def process_to_milliampere(self, value, range_min, range_max):
        """Converts a process parameter value to a 4-20 milliampere signal"""
        if value < range_min or value > range_max:
            raise ValueError("Process value out of range")
        mampere = 4.0 + (value - range_min) * (16.0 / (range_max - range_min))
        return round(mampere, 5)

    def milliampere_to_process(self, mampere, range_min, range_max):
        """Converts a 4-20 milliampere signal to a process parameter value"""
        if mampere < 4.0 or mampere > 20.0:
            raise ValueError("Milliampere signal out of range")
        value = range_min + (mampere - 4.0) * ((range_max - range_min) / 16.0)
        return round(value, 5)

root = tk.Tk()
app = ProcessToMilliampereConverter(root)

This example Python program using the Tkinter library to convert process parameter values into 4-20 milliampere signals, with options to enter the range and input type

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