Keil C环境下基于MAX1240的地磁信号采集

Geomagnetic Signal Acquisition Based on MAX1240 in Keil C Environment

Keil C环境下地磁信号采集采用MAX1240芯片。系统关断控制端由P1.3控制,转换前置高电平,平时置低电平。1240的3条数据线由89C51的P1.0、P1.1和P1.2分别控制。数据采集时,先置P1.3为高,将P1.0置0,置P1.1为0开始一次数据转换。其P1.2状态若为高,则转换完毕,反之继续。然后从P1.0输出时钟脉冲,每个上升沿后,读取7脚的状态,依次从高位到低位读取12位数据。转换结束,P1.1置为高,完成一次采集。

MAX1240 is adopted to acquire the geomagnetic signal .in Keil C environment. The power break input is controlled by P1.3 of 51 MPU. When transferring, P1.3 is set high, while set low when waiting. The communicating bus is controlled by P1.0, P1.1 and P1.3. When P1.3 is set high and P1.0 is set low, 1240 is selected and conversion is carried out. When P1.2 goes high, the conversion stops whereas the conversion continues. Then, the clock impulse is inputted from P1.0 after arising edge and 7-bit state is read. So the 12-bit data could be read in .sequence from high to low. At last, after conversion, the P1.1 is set high.