Availability Indicator

Since i work at my home office, my wife asked me a way to quickly know if i'm available or not.

So i built a small availability indicator, controlled remotly by Bluetooth.

For this, i used :

• Teensy v2
• a HC-05 (Linvor) bluetooth module
• a servo motor
• some wires
• a piece of wood
• paper, scissor, glue, tape etc...

It's quite simple, just connect as shown.

I used a Teensy without header pins, so the wires are directly soldered on the board

The servo is blocked by nails, on the top of the wooden piece.

Use the attached pdf file, print it, and glue it on a piece of cardboard, then cut . On the top the board, a hole was digged to allow the servo axis.

Same for the arrow (print, glue, cut), and it was fixed on the servo arm with tape.

There is two pieces of code : one for the Teensy, and one for the computer

Teensy

The Teensy code is Arduino compatible. We manage the Bluetooth module with the HardwareSerial library


#include 
#define MOTOR_PIN  4

HardwareSerial bt = HardwareSerial();
Servo myservo;
                 
char c;
int pos = 0;
char intBuffer[12];
String intData = "";
int delimiter = (int) '\n';

void setup()
{ 
  Serial.begin(9600);
  myservo.attach(MOTOR_PIN);  // attaches the servo on pin 9 to the servo object
  bt.begin(9600);
  bt.println("Start !!");
  myservo.write(130); // Force 'Free' position at startup
}

void loop()
{
      while (bt.available() ) {
        delay(3);
        int ch = bt.read();
        if (ch == -1) {
            // Handle error
            Serial.println("No Data");
        }
        else if (ch == delimiter) {
            Serial.println("delimiter -> break");
            break;
        }
        else {
            intData += (char) ch;
        }
      }
     
      if (intData.length() > 0) {
        // Copy read data into a char array for use by atoi
        // Include room for the null terminator
        int intLength = intData.length() + 1;
        intData.toCharArray(intBuffer, intLength);
        // Reinitialize intData for use next time around the loop
        intData = "";   
        // Convert ASCII-encoded integer to an int
        int pos = atoi(intBuffer);
     
        if(( pos > 0 ) && (pos <= 200 ) ) {
           //Serial.print ("go to pos : ");
           //Serial.println(int(pos) );
           myservo.write(pos);
           pos = 200;
         }      
       }
}




Desktop