Hi,

I wan to interface an external accelorometer with the waspmote.Can u please tell me how to cahnge the i2c address to access the new slave.

Thanku very much

Hi jahnavi,

you will have to use direct communication through the I2C, you can check the use of the Wire library upon which the I2C communication is implemented in the Arduino Reference Guide:

http://arduino.cc/en/Reference/Wire

Regards.

Hi Sir,

Is there any function similar to Wire.read() in waspmote?I am trying to read the data from the external accelorometer connected to the waspmopte can u please provide any example code to read the data from the slave.

Thanku very much

jahnavi,

We do not have this example available. Sorry about that.

However, you can take a look by yourself into wire library. You can use API browser, but keep in mind that is not updated with last API version, so always check .cpp and .h to be sure you are doing what you exactly want.

Regards.

Hi Sir,

In the waspAcc.h file the readregister function is defined as follows

int16_t readRegister(uint8_t address)
{
uint8_t aux = 0;
Wire.beginTransmission(i2cID);
Wire.send(regnum);
Wire.endTransmission();
Wire.requestFrom(i2cID, 1);
if(Wire.available())
{
aux = Wire.receive();
return aux;
}

return -1;
}

I this the address is the address of the register which i want to read from and i2cID is the slave address but how about Wire.send(regnum).Can u please explain me what does this function does and what is the "regnum" means.


Thanku very much

jahnavi,

This is not correct.

The function defined in WaspACC.cpp is as follows:

// reads a register from the accelerometer
// returns its value or -1 if error
int16_t WaspACC::readRegister(uint8_t regNum)
{
// reset the flag
flag &= ~(ACC_ERROR_READING);

uint8_t aux = 0;
Wire.beginTransmission(i2cID);
Wire.send(regNum);
Wire.endTransmission();

Wire.requestFrom(i2cID, 1);
if(Wire.available())
{
aux = Wire.receive();
return aux;
}

// error, activate the reading flag
flag |= ACC_ERROR_READING;

return -1;
}

where regNum is the register you want to read.

Regards.