DC4.5-5.5V DIY Laser Harp Kit String DIY Keyboard Kit Electronic Parts 7 Strings Electronic DIY Kit Technology Piano Mus

Parameters Supply voltage 4 5V 5 5V DC Laser harp principle The laser harp is a harp without strings Instead a bright beam of light is used The user simply dials the beam and plays a melody like a string The photoresistor and the single chip STC89C52 are composed of two parts When the beam emitted by the laser tube is blocked the corresponding photoresistor senses and changes the resistance value The system composed of the eight photoresistors generates high and low potential changes and the high low potential change of the photoresistor is read by the single chip microcomputer to complete the input of the operation command The MCU controls the data to transmit data through the serial port according to the instruction information and assigns the value of the p0 2 port of the docking speaker and the p1 port of the connected water lamp to generate a corresponding reaction When there is laser irradiation the microcontroller reads the voltage of the photoresistor at which time it is low When there is no laser irradiation the microcontroller reads the voltage of the photoresistor then it is high Thus when the light of the laser light is blocked the effect of the switch can be generated in the circuit The frequency of the human ear can be heard from 20Hz to 20kHz and the harp note frequency should also be in this range Just different notes have their own fixed frequency The above audio can be generated by the 16 bit timer that comes with the 52 MCU For examp