The appearance of the music card is shown in the figure.
The gift was made to the nephew for the new year and contains a voice greeting. The design is executed in the form of a book. The tape that holds the book closed is tied to a button. Having untied the ribbon, we open the book, and the square button, which is visible in the figure, is pressed.
The button, depressed, turns on the voice message. It can be your voice or just a piece of music from your favorite cartoon. LEDs are inserted in the corners, which, winking, give the gift even greater attractiveness.
Inside the book is all the electronic filling, which is visible in the figure.
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 sound. The concept of the entire filling on the concept.
The scheme is quite simple, by any beginner radio amateur. 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 LEDs of different glow colors, two GR2035 batteries or any others with a total voltage of 6V, a socket for batteries and a little wire. The power socket for this product, for not having a ready-made one, was made from the neck of a plastic bottle. A spring from the old remote control is installed in the bottom of the plug, and the threaded part of the neck is closed on one side by a grid of copper wire, which is the second electrode.
The only significant problem is the special aP89W24USB programmer, without which it is impossible to write a chip. But if you consider that such a gift can be not only a pleasant surprise for your dear people, but also a source of additional income, then you can go broke a few thousand rubles.