accel3d.cpp

00001 #include  "mbed.h"
00002 #include <stdio.h>
00003 #include <stdlib.h>
00004 #include  <time.h>
00005 
00006 //#include "udgs1.h"
00007 #define ACC_OK 0
00008 //SPI STSPI(SPI_MOSI, SPI_MISO, SPI_SCK);
00009 /*******************************************
00010 int initLIS3DH();
00011 int read3axes(short *tx,short *ty,short *tz);
00012 int readTemp(short *tmp);
00013 ******************************************/
00014 
00015 unsigned char spiwriteReg(unsigned char ad,unsigned char val);
00016 int spireadRegs(unsigned char ad,unsigned char *p,int bytes);
00017 unsigned char spireadReg(unsigned char ad);
00018 extern void spiFormat(int b,int m);
00019 extern void spiFrequency(int f);
00020 extern void spiWriteCS(int cs);
00021 extern int  spiWrite(int  wd);
00022 #define LIS2DW12_ID 0x44
00023 /*****************************************
00024   init LIS2DW12 LIS3DH ST micro 3-axes accelerometer
00025    SPI interface 
00026 *****************************************/
00027 int initLIS3DH()
00028 {
00029 //    STSPI = new SPI(SPI_MOSI, SPI_MISO, SPI_SCK, D6);
00030    
00031     spiFormat(8,3);  /* 8bit */
00032     spiFrequency(1000000); /* 1Mbps */
00033     spiWriteCS(1);
00034     wait_us(1);
00035    // printf("Who am I %02x\r\n", spireadReg(0x0f));
00036     spiwriteReg(0x21,0x84);  // 0x84(0101 0100) highpass filter/boot on 
00037     spiwriteReg(0x1f,0xc0);  // 
00038     spiwriteReg(0x20,0x35);  // 25hz 14bit
00039     spiwriteReg(0x25,0x14);  // max 4G
00040   //  spiwriteReg(0x23,0x98);  
00041     return (spireadReg(0x0f) - LIS2DW12_ID);
00042 }
00043 
00044 /*************************************************
00045   read 3-axes from LIS3DH
00046 *************************************************/
00047 int read3axes(short *tx,short *ty,short *tz)
00048 {
00049     int timeout=5;
00050     unsigned char regs[6];
00051     wait_us(50);
00052     while((spireadReg(0x07)&7)==0 && timeout--){wait_us(5);};
00053     spireadRegs(0x28,regs,6);// 14bit signed   1G = 413 9.8m/s**2
00054 //    STSPI.frequency(); //1MHz
00055     *tx = (short)(regs[0] | (regs[1]<<8)) >> 3;
00056     *ty = (short)(regs[2] | (regs[3]<<8)) >> 3;
00057     *tz = (short)(regs[4] | (regs[5]<<8)) >> 3;
00058     return(ACC_OK);
00059 }
00060 
00061 /*************************************************
00062   read temparture from LIS3DH -105 to  +152 degree
00063 *************************************************/
00064 int readTemp(short *tmp)
00065 {
00066     signed char t;
00067     t = spireadReg(0x26) + 25;
00068     if (tmp) *tmp = t;
00069     return(t);
00070 }
00071 
00072 
00073 /*************************************************
00074   Read a regster from SPI
00075 *************************************************/
00076 unsigned char spireadReg(unsigned char ad){
00077     unsigned char r;
00078     spiWriteCS(0);
00079     wait_us(1);
00080     spiWrite(ad | 0x80);  
00081     r = spiWrite(0);
00082     wait_us(1);
00083     spiWriteCS(1);
00084     return(r);
00085 }
00086 
00087 /*************************************************
00088   Read multi regsters from SPI
00089 *************************************************/
00090 int spireadRegs(unsigned char ad,unsigned char *p,int bytes){
00091 #if 0
00092    while(bytes--) {
00093       *p = spireadReg( ad );
00094       p++;
00095       ad++;
00096    }    
00097 #else   
00098    spiWriteCS(0);
00099     wait_us(1);
00100     spiWrite(ad | 0x80 );  
00101    while(bytes--) {
00102       *p++ = spiWrite(0);
00103    }
00104    wait_us(1);
00105    spiWriteCS(1);
00106 #endif  
00107     return(ACC_OK);
00108 }
00109 
00110 /*************************************************
00111   Write a regster via SPI
00112 *************************************************/
00113 unsigned char spiwriteReg(unsigned char ad,unsigned char val){
00114     unsigned char r;
00115     spiWriteCS(0);
00116     wait_us(1);
00117     spiWrite(ad);  
00118     r = spiWrite(val);
00119     wait_us(1);
00120     spiWriteCS(1);
00121     return(r);
00122 }