Temperature Measurement and Control System Design Summary: ZF02-96 is an ultra-small, ultra-low power, high-speed wireless data transmission module. Its excellent performance is the ideal device for low-power wireless data transmission applications. The main features, pin functions, software design, hardware connection methods, and specific application circuits of ZF02-96 are introduced in this article. S0100
Keywords: wireless data transmission; ZF02-96
Overview Since there are many kinds of wireless transceiver modules, it is very important to select the required modules in the design. The correct choice can avoid detours, reduce costs, and bring products to the market faster. The transceiver module ZF02-96 is an ultra-small, ultra-low power, high-speed wireless data transmission module. It adopts serial port transmission, application and programming is very simple, transmission efficiency is high, and fewer external components are required, the product development cost is low, power consumption is low, pins are less, and the package is small, thus it is advantageous to reduce the PCB area and cut costs.
ZF02-96 is composed of a single IC. It adopts FSK modulation, and receives and emits one, so it has strong anti-interference ability. It is suitable for embedded devices, adopts low transmission power, high sensitivity design, and can meet the requirements of wireless control without the need of The use of licenses is the ideal choice for low-power wireless data transmission. The main features of ZF02-96 are as follows:
â— Receive and launch one;
â— The operating frequency is the international common 433MHz data transmission frequency band;
â— adopts FSK modulation method, strong anti-interference ability, especially suitable for industrial control applications;
â—Using frequency synthesis technology, excellent frequency stability;
â— Sensitivity up to -118dBm;
The maximum transmission power is +10dBm;
â— Low operating voltage (3.3V~5V), low power consumption â— The maximum operating speed is 1200/2400/4800/9600/19200bps;
â— Ultra-small size;
â— can be directly connected to the microcontroller serial port, programming is very convenient;
â— Due to the low transmit power and high receiver sensitivity design, no license is required for use.
Pin Function of ZF02-96 The pin diagram of ZF02-96 module is shown as in Fig. 1. The function of each pin is as follows:
GND: power ground;
VCC: The power supply is 3.3V~5V
RXD: TTL data receiver;
TXD: TTL data transmitter;
SGND: signal ground;
D+(TXD): RS-232 Data Transmitter/ RS-485D+
D-(RXD): RS-232 Data Receiver / RS-485D-
ZF02-96 Application in Temperature Measurement and Control System ZF02-96 can realize point-to-point transmission of data acquisition, and can also form a point-to-multipoint bidirectional data transmission channel.
In this system, ZF02-96 can transmit the temperature data collected by the temperature sensor to the computer, and at the same time transmit the control signal sent from the computer to the single-chip microcomputer so as to achieve wireless data communication between the single-chip microcomputer and the computer. ZF02-96 can be directly connected to the serial port or I/O port of the MCU. When connecting, the receiving end RXD of the ZF02-96 wireless module should be connected to the sending end of the one-chip computer serial port, and the transmitting end TXD should be connected to the receiving end of the one-chip computer serial port. Using the microcontroller's I/O to control the module's transmit, channel conversion, and low-power modes.
Based on the characteristics of wireless transceiver modules, when designing software for the system, special attention should be paid to the formulation of communication protocols and the handling of error detection and correction. When there is no signal, the serial output of ZF02-96 is random data, so the first thing in the protocol is to be able to identify noise and valid data. Through testing and experimentation, it has been found that OXFF followed by OXOO is not likely to occur in noise. Therefore, the data sent by the MCU can be started with bytes of arbitrary contents (because the first byte of data is easily lost during sending), and then OXFF is followed by an OOXOO. The receiving protocol specifies that reception only starts with OXFF. And followed by a OXOO packet.
In addition, attention should be paid to the error correction of the data. This system adopts the checksum method for error detection and adopts the method of continuous transmission three times for error correction. The same data is transmitted three times in succession, and then each bit in the three data is compared at the receiving end. If this bit of at least two data is the same, the bit is correct. In short, a complete wireless transmission protocol is:
[Start 1] [Start 1] [Start 2] [Data 1] [Data 2] [Data 3] [Checksum].
The start 1 is OXFF and the start 2 is OXOO. If the checksum is correct, the data transmission is complete. Then compare data 1, data 2, and data 3, and take two of them to give the response signal. If the data itself is incomplete, then it will not respond, and the system will send the data again.
ZF02-96 can be widely used for remote control, telemetry, wireless meter reading, access control systems, cell paging, wireless tags, and identity recognition because the ZF02-96 system can complete point-to-point data acquisition and transmission and point-to-multipoint bidirectional data transmission. , non-contact RF smart cards, security systems, wireless remote control systems, biological signal acquisition, hydrometeorological monitoring, electronic station signs, intelligent transportation, wireless electronic weighing devices, industrial equipment data acquisition, various monitoring and control equipment.