Speaking clock-Time announcer for visually impaired persons-VOICEPLAYBACK

    Speaking clock-Time announcer for visually impaired persons


The main aim of this project is to assist the blind persons without the need of another person. Blind persons and aged people can do some works themselves but they cannot see time. This project announce the current time through speaker or through headphones whenever the user requests. This can be achieved easily by using advancement in technology especially in the field of embedded systems. 

Now a day’s so many useful technologies are coming out to make our life style more comfort, luxurious and secure. In this project we are using advanced ARM7 based LPC2148 32 bit micro controller.

The NXP (founded by Philips) LPC2148 is an ARM7TDMI-S based high-performance 32-bit RISC Microcontroller with Thumb extensions 512KB on-chip Flash ROM with In-System Programming (ISP) and In-Application Programming (IAP), 32KB RAM, Vectored Interrupt Controller, Two 10bit ADCs with 14 channels, USB 2.0 Full Speed Device Controller, Two UARTs, one with full modem interface. Two I2C serial interfaces, Two SPI serial interfaces Two 32-bit timers, Watchdog Timer, PWM unit, Real Time Clock with optional battery backup, Brown out detect circuit General purpose I/O pins. CPU clock up to 60 MHz, On-chip crystal oscillator and On-chip PLL. 

To play the voice messages we do not need any separate voice module because we can play that voice from ARM7 LPC2148 micro controller directly by saving pre recorded voice message in micro controller’s memory in the form of binary. 

And to read the current time also we do not need separate IC as LPC2148 has internal RTC (real time clock) only thing is we need to provide separate crystal oscillator for this RTC section 

BLOCK DIAGRAM:              

Software Tools:

  • KEIL IDE for developing micro controller code
  • ORCAD for designing schematics
  •  FLASH MAGIC for dumping the hex file into controller

Hardware Tools:

  • ARM7 LPC2148 Micro controller.
  • Audio amplifier.
  • Speaker or headphones 
  • Battery.
  • 32.768 KHZ crystal oscillator for RTC chip.


  • Accuracy in reading times 
  • Can get information about date and day also
  • Low power.


  • Useful for all visually impaired persons
  • Can be used in schools, homes for automatic time announcement 
  • Can be used in industries to announce some message depends upon the current time.