Infrared remote control:
At present, people's material and cultural living standards are improving day by day, and various household appliances have entered thousands of households. Among them, most household appliances have different remote controllers. In order to control an appliance, people often have to look for its corresponding remote controller everywhere, which brings a lot of inconvenience to people's lives. In order to solve this problem, this paper puts forward a design scheme of multifunctional remote controller: the remote controller can have the remote control function of various appliances through self-learning, which saves time and effort and avoids the trouble of facing multiple remote controllers at the same time.
Function:
1. Suitable for coding infrared remote control household appliances;
2. A variety of household appliances can be controlled remotely;
3. It has a learning/control multiplexing key, 5~ 10 device selection keys and 10~20 function control keys, and a device selection key and each function control key can control a device together;
4. Through a device selection key and various function control keys, the learning and control of common functions of various devices can be realized;
5. Low cost and strong anti-interference ability.
Principle:
The remote controller consists of infrared receiving and transmitting circuit, signal conditioning circuit and central controller 803 1. Program and data memory, keyboard and status indicating circuit.
The remote controller has two states: learning state and control state. When the remote controller is in the learning state, every time the user presses the control key, the infrared receiving circuit begins to receive the external infrared signal, and at the same time, it is converted into an electrical signal, which is then detected, shaped and amplified, and then sampled by the CPU at regular intervals. The binary data of each sampling point is stored in the designated storage unit in units of 8 bits for future control of the equipment. When the remote controller is in the control state, every time the user presses the control key, the CPU reads a series of binary data from the designated storage unit and serially outputs it to the signal holding circuit (the time interval between bits is equal to the sampling time interval). At the same time, the signal is modulated by the modulation circuit, and the modulated signal is amplified and emitted by the infrared emitting diode, thus controlling the function of the equipment corresponding to the key.