Chao at 05:47, 19 February 2021

2021-02-19T05:47:49Z

New page

== Schematic ==
<gallery>
File:Adxl345 schematic.jpg
</gallery>

== Datasheet ==
* [[:File:ADXL345.pdf|ADXL345 Datasheet]] adxl345 datasheet
* [[File:ADXL335.pdf|PDF datasheet]] adxl335 datasheet

== C51 Demo Code of ADXL335 ==
<syntaxhighlight lang="c">
//*****************************************************
//名称：单片机串口输出ADXL335角度值
//使用单片机：stc12c5a60s2
//供电：电压5v
//晶振：11.0592m
//X轴->(ADC0)P1.0
//Y轴->(ADC1)P1.1
//Z轴->(ADC1)P1.2
//用pc串口助手显示时，选择字符显示
//参考宏晶网址例程
//*****************************************************
#include "reg51.h"
#include "intrins.h"
#include <math.h> //Keil library
#include <stdio.h> //Keil library

//#define FOSC 18432000L
#define FOSC 11059200L //晶振11.0592M
#define BAUD 9600

typedef unsigned char BYTE;
typedef unsigned int WORD;

#define uchar unsigned char
#define uint unsigned int

/*Declare SFR associated with the ADC */
sfr AUXR1 = 0XA2;
sfr ADC_CONTR = 0xBC; //ADC control register
sfr ADC_RES = 0xBD; //ADC high 8-bit result register
sfr ADC_RESL = 0xBE;
sfr ADC_LOW2 = 0xBE; //ADC low 2-bit result register
sfr P1ASF = 0x9D; //P1 secondary function control register

/*Define ADC operation const for ADC_CONTR*/
#define ADC_POWER 0x80 //ADC power control bit
#define ADC_FLAG 0x10 //ADC complete flag
#define ADC_START 0x08 //ADC start control bit
#define ADC_SPEEDLL 0x00 //420 clocks
#define ADC_SPEEDL 0x20 //280 clocks
#define ADC_SPEEDH 0x40 //140 clocks
#define ADC_SPEEDHH 0x60 //70 clocks

void InitUart();
void InitADC();
void SendData(BYTE dat);
int GetADCResult(BYTE ch);
void Delay(WORD n);
uchar ge,shi,bai,qian,wan; //显示变量

void conversion(uint temp_data)
{
wan=temp_data/10000+0x30 ;
temp_data=temp_data%10000; //取余运算
qian=temp_data/1000+0x30 ;
temp_data=temp_data%1000; //取余运算
bai=temp_data/100+0x30 ;
temp_data=temp_data%100; //取余运算
shi=temp_data/10+0x30 ;
temp_data=temp_data%10; //取余运算
ge=temp_data+0x30;
}

/*----------------------------
Get ADC result
----------------------------*/
int GetADCResult(BYTE ch)
{ int AD10bitResult;
ADC_CONTR = ADC_POWER | ADC_SPEEDLL | ch | ADC_START;
_nop_(); //Must wait before inquiry
_nop_();
_nop_();
_nop_();
while (!(ADC_CONTR & ADC_FLAG));//Wait complete flag
ADC_CONTR &= ~ADC_FLAG; //Close ADC

AD10bitResult=ADC_RES;
AD10bitResult<<=8;
AD10bitResult|=ADC_RESL;
return AD10bitResult; //Return 10BIT ADC result
}
/*----------------------------
Initial UART
----------------------------*/
void InitUart()
{
SCON = 0x5a; //8 bit data ,no parity bit
TMOD = 0x20; //T1 as 8-bit auto reload
TH1 = TL1 = -(FOSC/12/32/BAUD); //Set Uart baudrate
TR1 = 1; //T1 start running
}

/*----------------------------
Initial ADC sfr
----------------------------*/
void InitADC()
{
P1ASF = 0xff; //Open 8 channels ADC function

AUXR1=AUXR1|0X04; //ad值左对齐
ADC_RES = 0; //Clear previous result
ADC_CONTR = ADC_POWER | ADC_SPEEDLL;
Delay(2); //ADC power-on and delay
}

/*----------------------------
Send one byte data to PC
Input: dat (UART data)
Output:-
----------------------------*/
void SendData(BYTE dat)
{
while (!TI); //Wait for the previous data is sent
TI = 0; //Clear TI flag
SBUF = dat; //Send current data
}

/*----------------------------
Software delay function
----------------------------*/
void Delay(WORD n)
{
WORD x;

while (n--)
{
x = 5000;
while (x--);
}
}

//******************************************************************************

void main()
{ int x,y,z;
float Q,T,K,Roll,Pitch;
InitUart(); //Init UART, use to show ADC result
InitADC(); //Init ADC sfr
while (1)
{
x=GetADCResult(0);
y=GetADCResult(1);
z=GetADCResult(2);
// 0-5v 对应 0-1024
// 3.3v/2 = 1.65v（0g时候值）
// 1.65v ->= 338 (AD值即0X0152)
x-=0X0152; //
y-=0X0152;
z-=0X0152;
Q=x;
T=y;
K=z;
Q=-Q;
Roll=(float)(((atan2(K,Q)*180)/3.14159265)+180);
Pitch=(float)(((atan2(K,T)*180)/3.14159265)+180);
conversion(Roll); //横滚角0-360度
//conversion(Pitch); //俯仰角0-360度
SendData(bai);
SendData(shi);
SendData(ge);

SendData(0x0d);
SendData(0x0a);//换行，回车

Delay(30);
}
}

</syntaxhighlight>

== Demo code and Library ==
* [https://code.google.com/p/adxl345-arduino/ ADXL 345 Library]
* [http://mbed.org/cookbook/ADXL345-Accelerometer mbed library]

[[category: Analog Accelerometer]]

ADXL345 - Revision history

Chao at 05:47, 19 February 2021