Circuit that can be adapted for any card or postcard with which you want to send a sentimental message to family and friends, to display a text message or an image in an LED matrix and play a stored voice message, everything is activated by middle of a push button.

For the voice message the ISD4002-120 integrated circuit is used, an analog voice recorder that can store any message of up to 120 seconds, and play it in a small speaker, the control of the integrated one is done through an SPI interface from the PIC16F873 microcontroller, which also controls and reproduces the message in the LED matrix, said message can be a text or an image that is moving through the matrix, and which must be stored in the EEPROM memory in the form of a matrix at the moment to program the microcontroller.

The audio output of the recorder is connected to a common small 8 ohm speaker through a small audio amplifier, the whole circuit is powered by two AA or AAA batteries, and its consumption while the circuit is deactivated is very low (100uA).

Victor Hugo Pachon
HUGO Tecnologia
vpachon@hugo.com.co
www.hugo.com.co