Low power radio frequency wireless data acquisition node circuit

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Low power radio frequency wireless data acquisition node circuit [Copy link]

With the development of integrated circuits, wireless communication technology and embedded technology, wireless communication networks have also emerged. Wireless sensor networks have the characteristics of low power consumption, low cost, distribution and self-organization. Traditional wireless RF communication modules are large in size and require control chips to control the RF modules, which increases the design cost and has poor mobility. The
　　continuous advancement of semiconductor technology has enabled processor chips to be integrated into a very small piece, and the price has become cheaper, and dedicated wireless network chips and technologies have also been developed. This paper uses TI's CC430F5137 to design and implement a node module for wireless networks. CC430F5137 is a chip with an internally integrated RF core. It has a built-in CC1101 RF core. A single chip can complete data collection, processing, transmission and reception, making the circuit board smaller and cheaper. In order to achieve low-power design of network nodes, this paper uses the wireless wake-up (WOR) function of the RF module. At the same time, the idle channel assessment (CCA) function of the RF core is used to improve the RF transmission algorithm and improve the accuracy of multiple nodes sending data to the repeater module.

　　Overall design scheme
　　The wireless sensor network is a network composed of a large number of cheap micro sensor nodes deployed in the monitoring area. It is a wireless network composed of a large number of static or mobile sensors in a self-organizing and multi-hop manner, which senses, collects, processes and transmits the information of the sensed objects in the geographical area covered by the network in a collaborative manner, and finally sends this information to the network owner. The wireless sensor network mainly realizes the three functions of data collection, processing and transmission.
　　Sensor network nodes are generally affected by the working environment, and the power consumption problem should be considered first. Considering the design of low power consumption requirements, the main control MCU of the node device chooses CC430F5137, and uses its built-in RF communication module for RF communication. Due to its low power consumption characteristics, it can be powered by batteries. The software part uses the wireless wake-up function of CC1101 to effectively reduce the power consumption of the system.
　　Multiple node devices can be connected in the wireless sensor network, and the address of each node device must be unique. The node device designed in this paper uses a dip switch to set the address of each node device to ensure that each node has a unique address. Sensor devices can be connected through the SPI interface or I2C bus, and different types of sensor devices can be flexibly connected to meet the requirements of testing different physical quantities. The system structure of the node is shown in Figure 1.

　

　　The power supply voltage range of CC430F5137 is 1.8～3.6 V. Two No. 7 batteries are used to provide 3 V DC voltage. The power consumption can be minimized by coordinating with the software settings. The key part of the system is the RF transmission, which uses a RF antenna module to ensure the stability of RF communication. This wireless module is connected by the RF_N and RF_P pins of the chip. In addition, according to the needs of RF transmission, a 26 MHz crystal oscillator is connected. The
　　P1.5, P1.6, and P1.7 pins of CC430F5137 can be used for serial communication and SPI communication. These three pins are used as serial port debugging. In addition, the P1.1, P1.2, and P1.3 pins can be used for SPI and I2C bus communication. These three interfaces are used to reserve the chip for connecting the sensor. The main circuit diagram of the system is shown in Figure 2.

　　In order to make the address of each node unique, an 8-bit DIP switch SW is used for address setting. As shown in Figure 3, the address of the terminal node can be set by the DIP switch, and 255 different addresses can be set. Each terminal node acts as a slave device to send data to the relay node, which is then sent by the relay node to the main control MCU for network management to complete the transmission of wireless sensor network data.

　　This paper uses TI's CC430F5137 chip and RF communication technology to design a wireless data acquisition node. This design can greatly reduce the size of the system. This system can collect a variety of signals and transmit the collected data to the intermediate data collection point safely and stably. The RF transmission function with improved carrier monitoring function and channel idle assessment function in the design can effectively improve the anti-interference performance when multiple nodes send data at the same time.

okhxyyo

Thanks for sharing. Is there any introduction to the specific range of the collected signal?

combat

I need this information, I will collect it first and then study it. Thank you very much.

alan000345

Learned

蜀禅文化

How much does it cost to develop such a product?

Aguilera

Shuchan Culture published on 2020-3-31 10:59 OP, how much does it cost to develop such a product?

Depends on R&D capabilities