0 Preface
Data acquisition plays a vital role in computer measurement, control and signal processing. Data collection is an important means of obtaining data. It is a process of automatically collecting information from analog or digital units under test, such as sensors or Other devices under test. The use of ARM internal A / D conversion resources, has the advantages of high conversion speed, reliable operation, and low design complexity. At the same time, ARM also has the characteristics of small size, high computing speed and high resolution of A/D conversion, which makes ARM widely used. This article uses the AT91M55800A in the ATM7 series of ATMEL to design a simple data acquisition scheme. The scheme has the characteristics of simple structure, easy development, high reliability and low price, and has certain practical value.
1 Structure and function of the data collection scheme
The structure of the scheme is shown in Figure 1.
The scheme consists of three parts: reception, A/D conversion and processing, and output. The solution is based on the AT91M55800A. The chip is a high-performance 32-bit processing chip with an 8-to-1 analog channel and a 10-bit A/D conversion channel. The pre-processing circuit isolates and amplifies the signal picked up by the sensor to 0~3 V required for A/D conversion. The processed analog signal is converted into a digital signal by the A/D conversion channel in the AT91M55800A, and correspondingly according to the requirements. Processing, and finally output by the liquid crystal display. At the same time, this scheme uses Flash memory as program memory for saving data.
2 hardware components
The AT91M55800A is a member of the ATM91 16/32-bit microcontroller family based on the ARM7TDMI core. It is directly connected to the off-chip memory through a fully programmable external bus interface, allowing read or write operations to be as fast as one clock cycle, through the ARM7TDMI processor core with on-chip SRAM, multiple peripheral function blocks, and analog interfaces. Integrated with a low-power oscillator on a single silicon. The AT91M55800A provides a highly flexible and cost effective solution for low power applications. Its main features are as follows:
a) integrated ARM7TDMI ARM Thumb processor core, high-performance 32-bit RISC architecture, high code density 16-bit instruction set, embedded ICE;
b) 8 kB on-chip SRAM, 32-bit data bus width, single clock cycle access, the program can expand up to 64 MB memory, software programmable 8-bit or 16-bit external data bus;
c) master/slave SPI interface, 8-bit to 16-bit programmable data length, 4 external slave chips;
d) Programmable watchdog circuit to improve the safety and reliability of the solution;
e) 58 programmable I/O lines, which expand the input and output lines;
f) advanced power management controller with normal, waiting, slow, standby and power down modes;
g) 8-priority, individually maskable vectored interrupt controller, 6-channel 16-bit timer/counter, 3 USARTs, each USART has 2 dedicated PDC channels;
h) 8-channel 10-bit A/D converter, 2-channel 10-bit D/A converter;
i) A clock generator with on-chip main oscillator and PLL multiplier, using the real-time clock of the on-chip 32 kHz oscillator.
Figure 2 shows the practical application circuit of the scheme.
The main control unit of the equipment is PLC and the HMI (Human Machine Interface) is 7" LCD colorful touch screen. The equipment has varieties of operating modes, and can automatically record and save working status.
The complete set of equipment is easy to operate, reliable in working, complete in protection and high in automation.
Fast Charging,Intelligent Fast Battery Charger,Agv Automatic Battery Charger,Agv Fast Charger
Xinxiang Taihang Jiaxin Electric Tech Co., Ltd , https://www.agvchargers.com