Published August 20, 2021 © GPL3+

Linux pc/server performance monitor

A handy little project that allows you to see your system stats on an LCD display and execute commands by pressing a button on the arduino.

IntermediateFull instructions provided2,001

Things used in this project

Hardware components

Arduino UNO

Any Arduino board with 10 or more I/O pins will do.

Adafruit RGB Backlight LCD - 16x2

Rotary potentiometer (generic)

Any generic potentiometer will do.

Jumper wires (generic)

Breadboard (generic)

Button (generic)

Resistor 10k ohm

Software apps and online services

Linux Any Distro

Story

I designed this status monitor because I wanted to see the status of my home server in real-time without any separate monitoring software. I searched the net for a few minutes and came across a few projects like this, but they were all missing something, that thing was a script that I actually understood and command execution with a button press. It took me a few evenings after school to put this together. The way it works is, there's a separate Python script running on the host machine, that feeds the system information from /proc/uptime and psutil (by Giampaolo Rodola) to the arduino over usb, using a python library called PySerial (by Chris Liechti). The arduino then prints the processed info onto a 16x2 LCD. The arduino also has two (or more if you please) buttons for executing commands on the host system.

This is my first ever published project, I hope someone finds it useful :)

Code

import psutil
import serial
import time
import os
ser = serial.Serial('/dev/ttyUSB0') #define serial port.
line = "nothing"; #create the variable where incoming communication is gonna be saved.
while True:
    sep = ',' 
    sep1 = '.'
    t = os.popen('uptime -p').read()[:-1] #open the file /proc/uptime and read it
    cpu = psutil.cpu_percent(interval=1) #reads the cpu åercetange every second
    if cpu <= 10: #if cpu percetange is less than 10, add a zero, eg. 5% -> 05%. This lessens the propability of a bug happening where ram has two "%" icons
        cpu = '0',str(cpu)
        cpu = str(cpu)
    cpu = str(cpu).replace('"', "")# Remove unecessary characters from string
    cpu = str(cpu).replace("'", "")# --||--
    cpu = str(cpu).replace(' ', "")# --||--
    cpu = 'CPU', str(cpu).split(sep1, 1)[0] #split the string at the first dot and remove anything behind it
    amount_of_ram = str(psutil.virtual_memory()[2]).split(sep1, 1)[0] # --||--
    ram = 'RAM', str(amount_of_ram) # Convert the variable to a string. (Why??)
    uptime = t #more spaghetti for the sake of it
    updisk = (str(uptime).split(sep, 1)[0],'/',psutil.disk_usage('/') [3], '%') #generate a string that contains the uptime and how much of the / drive is used. 
    downdisk = str(cpu) + '% ' + str(ram) + '%' #generate a string that contains the info regarding the RAM and the CPU. I know my naming scheme is stupid.
    downdisk = str(downdisk) #convert the variable to a string??
    upstr = str(updisk) #--||--
    upstr = upstr.replace("(", "") #replace all unecessary characters from the strings
    upstr = upstr.replace(",", "")
    upstr = upstr.replace("'", "")
    upstr = upstr.replace(")", "")
    upstr = upstr.replace("minutes", "m")
    upstr = upstr.replace("minute", "m")
    upstr = upstr.replace("hours", "h")
    upstr = upstr.replace("hour", "h")
    upstr = upstr.replace("days", "d")
    upstr = upstr.replace("day", "d")
    downdisk = downdisk.replace("(", "")
    downdisk = downdisk.replace(",", "")
    downdisk = downdisk.replace("'", "")
    downdisk = downdisk.replace(")", "")
    ser.write(b"*") # Let the arduino know we're about to write onto the second row
    ser.write(upstr.encode()) # Write the data 
    ser.write(b"#") # Let the arduino know we're about to write onto the first row
    ser.write(downdisk.encode())
    line = ser.readline() # Read the serial output
    if (not line == b'nothing\r\n'): # if false any buttons were'nt pressed, do nothing.
        if (line == b'reboot\r\n'): # A reboot was ordered by pressing a button
            os.system("reboot") #reboot the host system, replace the command if you wish to do something else when a button is pressed.
        if (line == b'shutdown\r\n'): # A shutdown was ordered
            os.system("shutdown now")    
    time.sleep(2) # Wait two seconds


# I'm sorry for the spaghetti and the excessive use of the commenting feature :)

#include <Wire.h> 
#include <LiquidCrystal.h>

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);
String inData;
const int buttonPin = 6;
const int buttonPin2 = 7;
const int ledPin = 8;
int buttonState = 0; 
int buttonState2 = 0;

void setup() {
    pinMode(buttonPin2, INPUT);
    pinMode(buttonPin, INPUT);
    pinMode(ledPin, OUTPUT);
    Serial.begin(9600);
    lcd.begin(16, 2);
}

void loop() {
  ledPin == HIGH;
  buttonState = digitalRead(buttonPin);
  buttonState2 = digitalRead(buttonPin2);
  if (buttonState == HIGH) {
      Serial.println("reboot");
      delay(250);
    
  }
  if (buttonState2 == HIGH) {
      Serial.println("shutdown");
      delay(250);
    
  }

    while (Serial.available() > 0)
    {
        char recieved = Serial.read();
        inData += recieved; 
        
        if (recieved == '*')
        {
            inData.remove(inData.length() -1, 1);
            lcd.setCursor(0,0);
            lcd.print(inData);
            inData = ""; 
            
            if(inData == "DIS")
            {
              delay(0); 
            }
  Serial.println("nothing");
            
        } 
        
        if (recieved == '#')
        {
            inData.remove(inData.length() -1, 1);
            lcd.setCursor(0,1);
            lcd.print(inData);
            inData = ""; 
        }
    }
}

Linux pc/server performance monitor

Things used in this project

Hardware components

Software apps and online services

Story

Schematics

Schematics

Code

The Python script for the host machine.

Arduino code

Credits

heposheikki

Comments

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Linux pc/server performance monitor

Linux pc/server performance monitor

Things used in this project

Hardware components

Software apps and online services

Story

Schematics

Schematics

Code

The Python script for the host machine.

Arduino code

Credits

heposheikki

Comments

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