Code cleanup

.gitignore

@@ -0,0 +1 @@
+settings.json

README.md

@@ -5,3 +5,11 @@ SCPI viewer for OWON SPM6103 Powersupply/Multimeter
 ## SCPI command
 
 - [ ] [OWON SPM SCPI manual](SPM_Series_programming_manual.pdf)
+
+## Autostart
+
+Add following to autostart app (Ubuntu):  
+``` bash
+bash -c "sleep 3 && python3 <path to script>/spm6103_viewer.py"
+```
+

spm6103_viewer.py

@@ -1,84 +1,244 @@
 import tkinter as tk
-from tkinter import messagebox
 from tkinter.font import Font
 import serial
+import os
+import json
+import threading
+import time
+
+
+class SerialManager:
+    def __init__(self, port="/dev/ttyUSB0", baud_rate=115200, reconnect_interval=2):
+        self.port_name = port
+        self.baud_rate = baud_rate
+        self.reconnect_interval = reconnect_interval
+        self.ser = None
+        self.lock = threading.Lock()
+        self.running = True
+        self.thread = threading.Thread(target=self._monitor_serial)
+        self.thread.daemon = True
+        self.thread.start()
+
+    def _monitor_serial(self):
+        while self.running:
+            with self.lock:
+                if self.ser is None or not self.ser.is_open:
+                    try:
+                        self.ser = serial.Serial(
+                            self.port_name, self.baud_rate, timeout=1
+                        )
+                        print(f"[INFO] Connected to {self.port_name}")
+                    except serial.SerialException as e:
+                        print(f"[WARN] Serial port error: {e}")
+                        self.ser = None
+            time.sleep(self.reconnect_interval)
+
+    def send_command(self, command):
+        with self.lock:
+            if self.ser and self.ser.is_open:
+                try:
+                    self.ser.write((command + "\n").encode("utf-8"))
+                    response = self.ser.readline().decode("utf-8").strip()
+                    return response
+                except Exception as e:
+                    print(f"[ERROR] Failed to send/receive: {e}")
+                    self.ser = None
+        return "Serial not connected"
+
+    def stop(self):
+        self.running = False
+        self.thread.join()
+        if self.ser and self.ser.is_open:
+            self.ser.close()
+
+
+# Set DPI scale for Wayland
+os.environ["GDK_SCALE"] = "2"
+
+
+# Load saved window geometry if exists
+def load_window_geometry():
+    try:
+        with open("settings.json", "r") as f:
+            settings = json.load(f)
+            return settings.get("geometry", "1080x200+100+100")  # Default geometry
+    except FileNotFoundError:
+        return "1080x200+100+100"  # Default geometry if no settings file
+
+
+# Save the window geometry when closing the app
+def save_window_geometry():
+    geometry = app.geometry()
+    settings = {"geometry": geometry}
+    with open("settings.json", "w") as f:
+        json.dump(settings, f)
+
 
 # Serial configuration
-port = '/dev/ttyUSB0'  # Adjust to your specific port
+ser = SerialManager(port="/dev/ttyUSB0")
-baud_rate = 115200     # Adjust to your device's baud rate
 
-try:
-    ser = serial.Serial(port, baud_rate, timeout=1)
-except serial.SerialException as e:
-    ser = None
-    print(f"Serial port error: {e}")
 
-def send_command(command):
+def send_command(cmd):
-    if not ser:
+    return ser.send_command(cmd)
-        return "Serial port not available"
+
-    ser.write((command + '\n').encode('utf-8'))
-    response = ser.readline().decode('utf-8').strip()
-    return response
 
 def get_id():
-    return send_command('*IDN?')
+    return send_command("*IDN?")
+
 
 def get_multimeter_data():
-    rawdata = send_command(f'CONFigure:ALL?')
+    rawdata = send_command(f"CONFigure:ALL?")
     return rawdata
 
+
 def get_powersupply_data():
-    rawdata = send_command(f'MEASure:ALL:INFO?')
+    rawdata = send_command(f"MEASure:ALL:INFO?")
     return rawdata
 
+
 def set_res_mode():
-    rawdata = send_command(f'[SENSe:]FUNCtion:RESistance')
+    rawdata = send_command(f"[SENSe:]FUNCtion:RESistance")
+    time.sleep(0.1)
+    rawdata = send_command(f"[SENSe:]RESistance:RANGe:AUTO ON")
     return rawdata
 
-def set_cont_mode():
+
-    rawdata = send_command(f'[SENSe:]FUNCtion:CONTinuity')
+def set_res200_mode():
+    rawdata = send_command(f"[SENSe:]FUNCtion:RESistance")
+    time.sleep(0.1)
+    rawdata = send_command(f"[SENSe:]RESistance:RANGe 200")
     return rawdata
 
+
+def set_cont_mode():
+    rawdata = send_command(f"[SENSe:]FUNCtion:CONTinuity")
+    return rawdata
+
+
+def set_diod_mode():
+    rawdata = send_command(f"[SENSe:]FUNCtion:DIODe")
+    return rawdata
+
+
+def set_voltdc_mode():
+    rawdata = send_command(f"[SENSe:]FUNCtion:VOLTage:DC")
+    return rawdata
+
+
+def set_voltac_mode():
+    rawdata = send_command(f"[SENSe:]FUNCtion:VOLTage:AC")
+    return rawdata
+
+
+def set_cap_mode():
+    rawdata = send_command(f"[SENSe:]FUNCtion:CAPacitance")
+    return rawdata
+
+
 # --- GUI Setup ---
 def fetch_device_info():
     # Fetch the device ID and Channel data
-    device_id = get_id()
     multimeter_data = get_multimeter_data()
 
-    # Update the labels
+    if "," in multimeter_data:
-    multimeter_type_var.set(multimeter_data.split(",")[0])
+        if len(multimeter_data.split(",")) >= 4:
-    multimeter_data_var.set(multimeter_data.split(",")[1])
+            # Update the labels
-    multimeter_range_var.set(multimeter_data.split(",")[3])
+            multimeter_type_var.set(multimeter_data.split(",")[0])
+            multimeter_data_var.set(
+                multimeter_data.split(",")[1].replace("+", "").replace("Ohm", "\u2126")
+            )
+            multimeter_range_var.set(
+                multimeter_data.split(",")[3].replace("Ohm", "\u2126")
+            )
 
-    # Schedule this function to be called again after 100ms 
+    # Schedule this function to be called again after 100ms
     app.after(100, fetch_device_info)
 
+
 app = tk.Tk()
-app.title("OWON SPM6103")
+app.title("SPM6103")
-app.geometry("1080x200")
+# Load and apply the saved geometry (size + position)
+app.geometry(load_window_geometry())
 app.configure(bg="black")
 
+# For cleanup on exit
+app.protocol(
+    "WM_DELETE_WINDOW", lambda: [save_window_geometry(), ser.stop(), app.quit()]
+)
+
 multimeter_type_var = tk.StringVar()
 multimeter_data_var = tk.StringVar()
 multimeter_range_var = tk.StringVar()
 
-# Create a font object
+# Create dynamic font objects
-fontSmall = Font(size=10)
+fontSmall = Font(size=6)
-fontMedium = Font(size=20)
+fontMedium = Font(size=14)
-fontBig = Font(size=80)
+fontBig = Font(size=24)
 
-app.rowconfigure(0, weight=1)
+resize_after_id = None
-app.rowconfigure(1, weight=1)
+
-app.rowconfigure(2, weight=1)
+
-app.columnconfigure(0, weight=1)
+def apply_font_resize():
-app.columnconfigure(1, weight=2)
+    width = app.winfo_width()
+
+    fontSmall.configure(size=max(6, int(width * 0.01)))
+    fontMedium.configure(size=max(14, int(width * 0.02)))
+    fontBig.configure(size=max(24, int(width * 0.09)))
+
+
+def resize_loop():
+    apply_font_resize()
+    app.after(200, resize_loop)
+
+
+resize_loop()  # start it once
+
+# Configure grid to be fully responsive
+app.rowconfigure(0, weight=20)  # Top - big
+app.rowconfigure(1, weight=1)  # Bottom - small
+
+app.columnconfigure(0, weight=1, uniform="equal", minsize=100)
+for i in range(7):
+    app.columnconfigure(i + 1, weight=1, uniform="equal")
 
 # Labels
-tk.Label(app, textvariable=multimeter_type_var, font=fontMedium, bg="black", fg="lightgrey").grid(column=0, row=0, sticky=tk.W)
+# Type and Range
-tk.Label(app, textvariable=multimeter_range_var, font=fontMedium, bg="black", fg="lightgrey").grid(column=1, row=0, sticky=tk.E)
+tk.Label(
-tk.Label(app, textvariable=multimeter_data_var, font=fontBig, bg="black", fg="lightgrey").grid(column=0, columnspan=2, row=1, sticky=tk.W)
+    app, textvariable=multimeter_type_var, font=fontMedium, bg="black", fg="lightgrey"
-tk.Button(app, text="RES", command=set_res_mode, font=fontSmall, bg="black", fg="lightgrey", border=False).grid(column=0, row=2, sticky=tk.W)
+).grid(column=0, columnspan=1, row=1, sticky="nsw", padx=0, pady=0)
-tk.Button(app, text="CONT", command=set_cont_mode, font=fontSmall, bg="black", fg="lightgrey", border=False).grid(column=1, row=2, sticky=tk.W)
+
+tk.Label(
+    app, textvariable=multimeter_range_var, font=fontMedium, bg="black", fg="lightgrey"
+).grid(column=0, columnspan=1, row=0, sticky="nw", padx=0, pady=0)
+
+# Data
+tk.Label(
+    app, textvariable=multimeter_data_var, font=fontBig, bg="black", fg="#afd787"
+).grid(column=1, columnspan=6, row=0, rowspan=1, sticky="nsew", padx=0, pady=10)
+
+# Buttons
+buttons = [
+    ("RES", set_res_mode),
+    ("RES200", set_res200_mode),
+    ("CONT", set_cont_mode),
+    ("VOLT:DC", set_voltdc_mode),
+    ("VOLT:AC", set_voltac_mode),
+    ("DIOD", set_diod_mode),
+    ("CAP", set_cap_mode),
+]
+
+for i, (label, cmd) in enumerate(buttons, start=1):
+    tk.Button(
+        app,
+        text=label,
+        command=cmd,
+        font=fontSmall,
+        bg="black",
+        fg="#444444",
+        highlightbackground="black",
+        borderwidth=0,
+    ).grid(column=i, row=1, sticky="nsew", padx=0, pady=0)
+
 
 # Initial fetch to start the auto-update process
 fetch_device_info()