Go Down

Topic: [Solved] Problem with float from 8-bit Arduino to Due (Read 730 times) previous topic - next topic


Apr 01, 2013, 10:32 pm Last Edit: Apr 03, 2013, 07:45 pm by ruizo Reason: 1
Hi, I´m trying to receive 3 float from an 8-bit Arduino Mini, which I know that it manage 4 bytes float, in a 12 byte array.
But I´m having troubles to convert it to Due´s float because I do not understand at all, how many bytes have a float in the Due,
(I think the float in Due it´s like an double, 8 bytes). I hope someone could confirm me that the Due´s float are 8 byte in memory and
tell me how to convert a 4 bytes float to a 8 bytes float, I´m trying to do it with "union" with no results.

Thanks and regards.

Update: I found "Sizeof" function in the reference, I will test it on the Due and I will post the results.


Apr 03, 2013, 07:44 pm Last Edit: Apr 03, 2013, 07:49 pm by ruizo Reason: 1
Finally it works  XD

sizeof() told me that float are 4 bytes long and double are 8 bytes long on Due, I didn't understood well in the reference  :smiley-roll-sweat:

Code: [Select]
//  Test code to send binary data from 9 DOF Razor IMU to Arduino Due
//  Programa de Prueba para comprobar que el Arduino Due recibe correctamente
//  los datos del 9 DOF Razor IMU y los procesa.
//  Miguel Angel Ruiz 2013

const int TOTAL_BYTES = 12 ; // the total bytes in a message
char MESSAGE [12] = {'N','N','N','N','N','N','N','N','N','N','N','N',};  //  String for testing

union y_tag {
   byte by[4];
   float yval;
} y;

union p_tag {
   byte bp[4];
   float pval;
} p;

union r_tag {
   byte br[4];
   float rval;
} r;

float yaw;
float pitch;
float roll;

void setup(){
 Serial.println("Iniciando IMU");
 Serial1.print("#oe0"); // Disable Error Output
 Serial1.print("#ob");  // Binary Output Format Selected
 Serial1.print("#o0");  // Disable Continuos Data Streaming
 Serial.println("Arranque listo, comenzando");
 Serial.print("Mensaje de prueba -> ");
 for(int i=0; i<12; i++){
   Serial.print(MESSAGE[i], HEX);
 Serial1.print("#f");  // Request one frame of data

}// Fin de setup

void loop(){
 if ( Serial1.available() >= TOTAL_BYTES){
       y.by[0] = Serial1.read();
       y.by[1] = Serial1.read();
       y.by[2] = Serial1.read();
       y.by[3] = Serial1.read();
       yaw = y.yval;
       p.bp[0] = Serial1.read();
       p.bp[1] = Serial1.read();
       p.bp[2] = Serial1.read();
       p.bp[3] = Serial1.read();
       pitch = p.pval;
       r.br[0] = Serial1.read();
       r.br[1] = Serial1.read();
       r.br[2] = Serial1.read();
       r.br[3] = Serial1.read();
       roll = r.rval;
       Serial.print("Received IMU msg, Yaw = ");
       Serial.print(yaw, 2);
       Serial.print(", pitch = ");
       Serial.print(pitch, 2);
       Serial.print(", roll = ");
       Serial.println(roll, 2);
/*    for(int i=0; i<12; i++){          //  Old code for testing
      MESSAGE[i] = Serial1.read();
   Serial1.print("#f");                 //  Request another frame of data
}// Fin del loop

Go Up

Please enter a valid email to subscribe

Confirm your email address

We need to confirm your email address.
To complete the subscription, please click the link in the email we just sent you.

Thank you for subscribing!

via Egeo 16
Torino, 10131