In this paper, the characteristics of Si4010 and Si4463 RF chips developed by Silicon Laboratories and the design of remote control system for garage door controller are introduced. Provide reference for product development and other wireless application design in related industries. With the development of society, people’s living standard is constantly improving, and the purchase of private cars is increasing.
Some new residential areas, especially high-end residential areas, regard the private garage as the standard allocation of residential value. The transmitting part of the traditional garage door controller is composed of a microprocessor (MCU) and a surface acoustic wave (SAW) transmitter, and the receiving part adopts a superheterodyne receiving module. The advantage is that the wireless transmitting and receiving circuit can process the wireless receiving and receiving signals through microprocessor without software configuration, but the disadvantage is that the peripheral electronic components are complex, high power consumption, low sensitivity, vulnerable to environmental temperature changes, and the transmission form is single. The wireless transmitter chip Si4010 and the wireless transceiver chip Si4463 developed by Silicon Laboratories company can make the whole transceiver system simple in structure, convenient in control, stable in performance, with very low power consumption, and can realize a variety of transmission modes through software configuration. They are very suitable for remote control system of garage door controller, and bring convenience to our daily life. Si4010 is a single chip remote control IC developed by Silicon Laboratories. It uses a patented crystal-free oscillator architecture. Its carrier frequency accuracy can reach ( 150 ppm) in commercial temperature range and ( 250ppm) in industrial temperature range. Its accuracy is twice as high as that of traditional surface wave (SAW) transmitters, and no external crystal oscillator is needed. Si4010 includes an embedded compatible 8051 microcontroller (MCU), 4 kB of RAM, 8 kB of one-time programming (OTP) non-volatile memory, a 128-bit EEPROM and a 12 kB ROM for library functions. It can provide 1.8V to 3.6V voltage range, standby current with current consumption less than 10nA and peak current less than 20mA, as well as touch wake-up mode with low power consumption. FSK, GFSK and OOK modulation modes are supported. Silicon Laboratories Si4463 chip is a high-performance, low-current transceiver. The sub-GHz band of the load ranges from 119M to 1050MHz. It has very low working and standby currents. The output power of up to 20dBm has excellent transmission efficiency. Supports the modulation schemes of FSK, GFSK and OOK. The working voltage ranges from 1.
8V to 3.6V. It is convenient to switch between transmitter and receiver by setting electronic switches inside. Because the Si4010 chip is a single chip remote control IC and integrates 8051 core internally, it is very simple as the peripheral circuit of remote control transmitter. The transmitting system consists of keyboard circuit, LED indicator lamp and Si4010 radio frequency transmitting part. The key circuit has four keys: opening, closing, stopping and lighting control. GPIO port provides two kinds of settings for the use of keys, Pullup Roff Option mode and Matrix Mode Option mode. When configuring into Pullup Roff Option mode, up to nine independent keys are supported. Because of the built-in pull-up resistance of the chip, keys only need to connect to GPIO directly. If there are too many keys for users, Matrix Mode Option mode can provide a matrix keyboard of 3*6. The two modes can be waked up by keystrokes when the chip is in standby state. The LED indicator can be directly connected to the chip GPIO5 foot, and the Si4010 GPIO5 is a special LED driver pin designed for users. The three current levels of the LED driver can be adjusted by configuring special function registers, and the LED lamp can be turned on or off by controlling the high and low levels of the GPIO5. The radio frequency emission part of Si4010 is simpler, and the corresponding inductors and capacitors can be matched by TXP and TXP pins. The receiving system of the controller end is realized by the combination of microprocessor and Si4463. Microprocessor is connected with Si4463 through standard SPI interface. It is mainly used for the configuration of initialization parameters and the return of data received by microprocessor.
In addition to SPI interface, Si4463 can also be configured as direct connection mode of demodulated signal through WDS software, and the demodulated waveform can be directly docked to micro via GPIO port. Processor pins provide a flexible way for users to process data later. The Si4463 RF receiving circuit matches the inductors and capacitors according to different carrier frequencies. In addition, because Si4463 has the function of sending and receiving as one, two pins of GPIO2 and GPIO3 are set inside the chip as electronic switches, which connect the two pins to the microprocessor. The microprocessor can conveniently control Si4463 in the receiving or sending mode.
In the aspect of software programming of remote controller, Si4010 provides users with a function library that can be directly called. The content of the function library is rich, which includes key service module, thermostatic element data encoding module, AES encryption module, battery voltage measurement module and so on. Through reading the PTS structure provided by the key module, the vector state information of the key is obtained; after combining the data needed to be transmitted, the encryption operation is carried out through the AES encryption module or user-defined encryption algorithm, and most of the data in the garage door controller industry are transmitted by rolling code to prevent remote control information from being duplicated by others; and the battery voltage inspection which comes with the chip function library is used. The measurement module can monitor the voltage state of the remote controller in real time, set the threshold in the software. When the voltage drops to the threshold voltage, the user can be informed to replace the battery in time by the remote controller LED indicator lamp or send commands to the controller to prevent the failure of the remote controller caused by the low battery voltage in the future. Si4463 first uses WDS configuration software to generate configuration header file according to data transmission requirement, which is included in the project. Referring to API programming manual provided by Si4463, the task of remote control data reception can be easily completed. This system adopts high integration radio frequency IC chip, which greatly shortens the development time from hardware circuit design and software program writing, and is convenient for product developers to design ideal products quickly.
Because the controller adopts the Si4463 transceiver integrated chip, it can be used as the receiving signal of remote controller, and the transmitting function of the chip can be reserved for future expansion. For example, the smart home platform such as the location of the garage door and the state information to the center.
In addition, the wireless transceiver system can be further extended to data acquisition, industrial control and security products.