Wireless remote control device based on AT89C2051

EL-C1600N100013-B

Crystal oscillator

L0504-Murata muRata common mode inductor 90Ω 150mA

Among the wireless transceiver components, 315MHz transceiver components are commonly used. For example, in the automotive anti-theft application, there are many 315MHz components. The module sold by the general electronics store has three terminals and one data terminal. The other two are the power supply, and relatively cheap, the author bought a pair of only 13 yuan, if you want to make it is relatively difficult, because the high-frequency circuit like the remote control circuit is very professional debugging, need For special equipment and instruments, you can refer to this information.

Circuit function

The wireless transceiver circuit introduced in this paper uses ATMEL's AT89C2051 microcontroller as the core device of the encoding and decoding circuit. The receiving end uses the 1602-character liquid crystal display to display the received data.

working principle

First, the coding circuit will be introduced. In the process of use, the author directly connects the three terminals of the sending module with the self-made learning board. No other electronic components are added. It is the minimum system of the single-chip microcomputer. S1 and S2 are two buttons. The program is not used. Figure 1 shows the circuit diagram of the transmitting end, and Figure 2 shows the circuit diagram of the receiving end.

Figure 1 Transmitter circuit diagram

Figure 2 Receiver circuit diagram

The receiving end will send the received data to the MCU, and will also drive the LED to correct the hardware and software. If the data is received successfully, it will be displayed on the 1602 LCD. Because this article mainly introduces the wireless remote control, about 1602 characters. The principle and application of the liquid crystal display are not introduced. The reader can refer to the related articles of the "Radio". If the cost and the difficulty of the program are considered, the 7-segment digital tube or even the LED can be used for data display. . Also note that the frequency of the clock crystal of the transmitter and receiver must be the same, otherwise programming will be very cumbersome and even the data will not be received properly, which is mentioned in the introduction of the program.

Software, borrowing from the infrared remote control coding idea, first send the pilot pulse, followed by the data code and data inverse code, this process is completed in the timed interrupt, the timing time is called, an adder is called, and then The result is sent as data, and the counter is cleared and cleared to the next cycle.