Saludos amigos... tengo un problemita que no entiendo que sucede.. empece hace poco con arduino para un proyecto que estoy realizando y necesito almacenar los datos de mi acelerometro ADXL345 en una micro SD.
El problema radica que al momento de querer visualizar los datos que se debieran guardar en la tarjeta a travez del puerto serial solo muestra 0.00 y se almacena 0.00.. y por mas que mueva el acelerometro no hace nada. cada dispositivo funciona sin problemas a la hora de utilizarlos individualmente.
Estoy usando un arduino UNO, un acelerometro ADXL345 digita y un shield SD...( este shield pertenece a un GPS logger shield)... pero por el momento lo que me interesa es poder almacenar los datos del acelerometro ya que con los del GPS no tengo problema alguno.
lo probe con ese shield... y con un shield solo de SD
el codigo lo dejo a continuacion..
//Add the SPI library so we can communicate with the ADXL345 sensor
#include <SPI.h>
#include <SD.h>
int CS=10;
char POWER_CTL = 0x2D; //Power Control Register
char DATA_FORMAT = 0x31;
char DATAX0 = 0x32; //X-Axis Data 0
char DATAX1 = 0x33; //X-Axis Data 1
char DATAY0 = 0x34; //Y-Axis Data 0
char DATAY1 = 0x35; //Y-Axis Data 1
char DATAZ0 = 0x36; //Z-Axis Data 0
char DATAZ1 = 0x37; //Z-Axis Data 1
char values[10];
//These variables will be used to hold the x,y and z axis accelerometer values.
double x,y,z; // valor del sensor
float xg,yg,zg; // valor del angulo
double ix,iy,iz; // valir de porcentaje de pendiente
const int CS_SD =8; // para la sd
void setup(){
//Initiate an SPI communication instance.
SPI.begin();
//Configure the SPI connection for the ADXL345.
SPI.setDataMode(SPI_MODE3);
//Create a serial connection to display the data on the terminal.
Serial.begin(9600);
//Set up the Chip Select pin to be an output from the Arduino.
pinMode(CS, OUTPUT);
//Before communication starts, the Chip Select pin needs to be set high.
digitalWrite(CS, HIGH);
//Put the ADXL345 into +/- 4G range by writing the value 0x01 to the DATA_FORMAT register.
writeRegister(DATA_FORMAT, 0x01);
//Put the ADXL345 into Measurement Mode by writing 0x08 to the POWER_CTL register.
writeRegister(POWER_CTL, 0x08); //Measurement mode
while (!Serial) {
;
}
if (!SD.begin(CS_SD)) {
Serial.println("Card failed, or not present");
return;
}
Serial.println("Card initialized.");
}
void loop(){
/
readRegister(DATAX0, 6, values);
//The X value is stored in values[0] and values[1].
x =(int)( ( ( ( unsigned int )( values[1]&255 )) << 8 ) | (unsigned int)(values[0])&255);
//The Y value is stored in values[2] and values[3].
y = (int)( ( ( ( unsigned int )( values[3]&255 )) << 8 ) | (unsigned int)(values[2])&255);
//The Z value is stored in values[4] and values[5].
z = (int)( ( ( ( unsigned int )( values[5]&255 )) << 8 ) | (unsigned int)(values[4])&255);
xg = RAD_TO_DEG * (atan2(-x, -z) + PI); // para el calculo de grandos
ix= tan(DEG_TO_RAD *xg); // para el porcentaje de inclinacion
Serial.println(x,4);
Serial.println(ix, 3);
File dataFile = SD.open("prueba.txt", FILE_WRITE);
if(dataFile){
dataFile.println(ix,3);
dataFile.close();
}else{
Serial.println("Error");
}
delay(1000);
}
//This function will write a value to a register on the ADXL345.
//Parameters:
// char registerAddress - The register to write a value to
// char value - The value to be written to the specified register.
void writeRegister(char registerAddress, char value){
//Set Chip Select pin low to signal the beginning of an SPI packet.
digitalWrite(CS, LOW);
//Transfer the register address over SPI.
SPI.transfer(registerAddress);
//Transfer the desired register value over SPI.
SPI.transfer(value);
//Set the Chip Select pin high to signal the end of an SPI packet.
digitalWrite(CS, HIGH);
}
//This function will read a certain number of registers starting from a specified address and store their values in a buffer.
//Parameters:
// char registerAddress - The register addresse to start the read sequence from.
// int numBytes - The number of registers that should be read.
// char * values - A pointer to a buffer where the results of the operation should be stored.
void readRegister(char registerAddress, int numBytes, char * values){
//Since we're performing a read operation, the most significant bit of the register address should be set.
char address = 0x80 | registerAddress;
//If we're doing a multi-byte read, bit 6 needs to be set as well.
if(numBytes > 1)address = address | 0x40;
//Set the Chip select pin low to start an SPI packet.
digitalWrite(CS, LOW);
//Transfer the starting register address that needs to be read.
SPI.transfer(address);
//Continue to read registers until we've read the number specified, storing the results to the input buffer.
for(int i=0; i<numBytes; i++){
values[i] = SPI.transfer(0x00);
}
//Set the Chips Select pin high to end the SPI packet.
digitalWrite(CS, HIGH);
}
Espero me puedan dar alguna sugerencia para resolver esto..
la idea de mi proyecto a grandes rasgos es almacenar la posicion (GPS) y la pendiente que exsiste en ese punto, pero en este punto estoy fallando. por eso solo pido algun consejo con el acelerometro y su almacenamiento en SD.
