The appearance of the musical postcard is shown in the figure.
The gift was made to my nephew for the New Year and contains a voice greeting. The design is made in the form of a book. The ribbon that holds the book closed is tied with a button. Having untied the tape, we open the book, and the square button, which is visible in the figure, is pressed.
The button, when pressed, turns on the voice message. It could be your voice or just a piece of music from your favorite cartoon. Inserted in the corners LEDs, which, winking at each other, make the gift even more attractive.
Inside the book there is all the electronic stuffing that is visible in the picture.
The basis is a small board with a one-time programmable sound chip aP8942A.
This chip allows you to record up to 42 seconds of audio. Schematic diagram of the entire filling on the circuit diagram.
The scheme is quite simple, any novice radio amateur can do it. To assemble the device, you will need, in addition to the sound chip itself, a speaker with a power of 0.5 W and a resistance of 8 Ohms, a normally closed button (one whose contacts open when pressed), two KT315 transistors, four LED different colors of light, two GR2035 batteries or any others with a total voltage of 6V, a socket for batteries and some mounting wire. The power socket for this product, due to the lack of a ready-made one, was made from the neck of a plastic bottle. A spring from an old remote control is installed in the bottom of the plug, and the threaded part of the neck on one side is closed with a mesh of copper wire, which is the second electrode.
The only significant problem is the special programmer aP89W24USB, without which it is impossible to write the microcircuit. But if you consider that such a gift can not only be a pleasant surprise for people dear to you, but also a source of additional income, then you can go broke for several thousand rubles.
