Introduction: 'Time to Get Out of Your Chair' Alarm

Picture of 'Time to Get Out of Your Chair' Alarm

This is a device that warns and sets off an alarm when you've been sitting on your chair for too long, reminding you to get off of your @$$ and get some exercise! It's the Pomodoro Clock of Chairs, one chair to rule them all!

Working as a software developer as a day job means I am almost always glued to a chair. Many older people suffer from back problems due to the nature of the job. I have created a mechanism that may circumvent this problem by detecting how long you've been sitting on a chair and sounding an alarm if you have been there for too long!

Step 1: BoM

Picture of BoM

* Photosensor

* 10kΩ Resistor

* Jumper Cables

* Arduino


* Soldering Iron

Step 2: Solder

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Since I wanted to go breadboard-less we'd need to solder the resistor onto one of the pins of the photosensor (call this pin 1) since the photosensor will use a voltage divider to relay input signals to the Arduino.

Step 3: Connections

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Follow the table below for the connections between the I/Os and the

I/OI/O pinArduino Pin

* Order of pins do not matter for the buzzer

** The Arduino board has at least 3 GND pins

Step 4: Code

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 * 'Get out of your chair alarm!'
 * By TechMartian
/cosntants for the pins where sensors are plugged into.
const int sensorPin = 0;
const int buzzPin = 9;
unsigned long minute1; 
float time1;
//Set up some global variables for the light level an initial value.
int bright;  // initial value
int lightVal;   // light reading
void setup()
  // We'll set up the LED pin to be an output.
  bright = 900;
  //we will take a single reading from the light sensor and store it in the lightCal        //variable. This will give us a prelinary value to compare against in the loop
void loop()
  lightVal = analogRead(sensorPin); // read the current light levels
  //if lightVal is less than our initial reading withing a threshold then it is dark.
  if(lightVal <  bright)
      // reset the timer, person began to sit down
      minute1 = minute();
  }  else   // otherwise it's bright
      hour1 = -1;
      minute1 = -1;
  unsigned long minute = minute();
  if (abs(60 - minute + minute1 )>20){
    // time to stand up
    while (lightVal <  bright) {  // still sitting
    tone (buzzPin, 1000, 100);
    delay (100);
    noTone(buzzPin);  }

Step 5: Setup

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Place the photosensor at the back of the char where you won't sit on it, but will be blocked off of the light when you sit down.

Step 6: Enjoy!

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Enjoy your lengthened and healthier lifestyle!

Live long and Prosper!


About This Instructable




Bio: Aerospace Engineer working in Software Development with a passion for Hardware.
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