树莓派开发ADC芯片CS1237（C语言和python库开发）

源码地址https://github.com/dyingstraw/CS1237

一、准备工作

1.安装树莓派官方系统

安装树莓派官方系统

2.安装wiringpi库

sudo apt-get install git-coresudo geit clone git://git.drogon.net/wiringPicd wieingPisudo ./build

安装结束之后
运行命令 gpio readall

如果出现这个树莓派引脚图，说明安装成功。进行下一步
3.新建一个CS1237.c和CS1237.h文件

CS1237.h

#ifndef __CS1237__h__#define __CS1237__h__#include <stdio.h>#include <wiringPi.h>#define SCK 1#define DOUT 4#define SCK_LOW digitalWrite(SCK,0)#define SCK_HIGN digitalWrite(SCK,1)//树莓派wiring引脚对应关系如下//AD转换数值与实际重量的增益// #include <Python.h>static double CS1237P = 0.0078742;//初始化void CS1237Init(){    wiringPiSetup();    pinMode(SCK,OUTPUT);    pinMode(DOUT,INPUT);    pullUpDnControl(DOUT,PUD_UP);    SCK_LOW;}//是否转换完毕int CS1237isReady(){    if(digitalRead(DOUT)==0)    {        return 1;    }    return 0;}//配置函数void CS1237Config(){    //no op}//一次上升沿void CS1237ClockUp(){    SCK_LOW;    delayMicroseconds(10);    SCK_HIGN;    delayMicroseconds(10);}//读数据int CS1237Read(){    int tmp=0;    int now=0;    int i;    int num=100;    while(!CS1237isReady())    {        ;    }    for(i=0;i<23;i++)    {        SCK_LOW;        delayMicroseconds(10);        SCK_HIGN;        delayMicroseconds(10);        now = digitalRead(DOUT);                //printf("%d,",now );        tmp *=2;        tmp = tmp+now;        SCK_LOW;    }    SCK_LOW;    CS1237ClockUp();    CS1237ClockUp();    CS1237ClockUp();    SCK_LOW;        return tmp;}//得到平均立波得到实际数值//num：采样次数int getValue(int num){    int i=0;    int tmp=0;    long weight = 0;    for(i=0;i<num;i++)    {        tmp = CS1237Read();        weight =weight + tmp;    }    return weight/num;}int getHelp(int num){    return num*3;}#endif

CS1237.c

#include "CS1237.h"int main(){    int tmp,Orign;    printf("hello rasp  %s\n","dsc" );    //初始化CS1237    CS1237Init();    //得到初试点（0点校正）    Orign = getValue(200);    printf("Orign value is %d\n", Orign);    while(1)    {        tmp = getValue(100);        printf("now is %lf\n", (tmp-Orign)*CS1237P);    }}

代码写好之后在同目录下编译：
gcc CS1237.c -o test -lwiringPi
运行
./test

二、将程序封装为python可调用的库

python 调用C的方式：

新建一个CS1237.如下

#include <stdio.h>#include <wiringPi.h>#define SCK 1#define DOUT 4#define SCK_LOW digitalWrite(SCK,0)#define SCK_HIGN digitalWrite(SCK,1)//树莓派wiring引脚对应关系如下//AD转换数值与实际重量的增益#include <Python.h>static double CS1237P = 0.0078742;//初始化void CS1237Init(){    wiringPiSetup();    pinMode(SCK,OUTPUT);    pinMode(DOUT,INPUT);    pullUpDnControl(DOUT,PUD_UP);    SCK_LOW;}//是否转换完毕int CS1237isReady(){    if(digitalRead(DOUT)==0)    {        return 1;    }    return 0;}//配置函数void CS1237Config(){    //no op}//一次上升沿void CS1237ClockUp(){    SCK_LOW;    delayMicroseconds(10);    SCK_HIGN;    delayMicroseconds(10);}//读数据int CS1237Read(){    int tmp=0;    int now=0;    int i;    int num=100;    while(!CS1237isReady())    {        ;    }    for(i=0;i<23;i++)    {        SCK_LOW;        delayMicroseconds(10);        SCK_HIGN;        delayMicroseconds(10);        now = digitalRead(DOUT);                //printf("%d,",now );        tmp *=2;        tmp = tmp+now;        SCK_LOW;    }    SCK_LOW;    CS1237ClockUp();    CS1237ClockUp();    CS1237ClockUp();    SCK_LOW;        return tmp;}//得到平均立波得到实际数值//num：采样次数int getValue(int num){    int i=0;    int tmp=0;    long weight = 0;    for(i=0;i<num;i++)    {        tmp = CS1237Read();        weight =weight + tmp;    }    return weight/num;}int getHelp(int num){    return num*3;}PyObject * wrap_getValue(PyObject *self,PyObject *args){    int num;    int weight;    if(!PyArg_ParseTuple(args,"i:getValue",&num))        return NULL;    weight = getValue(num);    return Py_BuildValue("i",weight);}PyObject * wrap_getHelp(PyObject *self,PyObject *args){    int num;    int weight;    if(!PyArg_ParseTuple(args,"i:getValue",&num))        return NULL;    weight = getHelp(num);    return Py_BuildValue("i",weight);}PyObject * wrap_CS1237Init(PyObject *self,PyObject *args){    int num;    int weight;    CS1237Init();    return NULL;}static PyMethodDef CS1237Methods[]={    {"getValue",wrap_getValue,METH_VARARGS,"get weignt adc valie"},    {"getHelp",wrap_getHelp,METH_VARARGS,"get help adc valie"},    {"CS1237Init",wrap_CS1237Init,METH_VARARGS,"get help adc valie"},    {NULL,NULL}};void initCS1237(){    PyObject *m;    CS1237Init();    m = Py_InitModule("CS1237",CS1237Methods);}

然后交叉编译：
命令代码(路径按照自己的)
gcc -fPIC CS1237.c -o CS1237.so -shared -I/usr/include/python2.7 -I/usr/lib/python2.7/config

然后在此目录下新建一个test.py验证一下：

# test.py# coding=utf-8import CS1237tmp = CS1302.getValue(20)print temp

执行python test.py 运行结果出来了：

33077

关于python引用C语言的若干种方式，请参考[Python调用C/C++的种种方法]1