Easy Transfer Byte Limit?

[Anonymous]

Hello Bill.

Firstly, great work on the transfer libraries they work great for most of my applications

I’m using I2C method and I have an application that needs to transfer 24 ints from one arduino to another but it appears that there is a limit of 12 integers with the transfer. Once I put in the 13th integer communication fails. I was just wondering if this is a know bug/limit and if there is any way of getting round this?

Many thanks and  Best Regards,

 

Lee

[Anonymous]

outrage, just seen your post.  Possibly the problem is that there is a limit of 32 bytes, I believe, when using the wire library.  So 24 ints would exceed this since 16 ints = 32 bytes.

 

Hope this helps

[Anonymous]

I Just ran into the same issue – there is a fairly easy work around – use one int as an  ID and send the other  int´s in multiple packages – you could do one packet per loop – I managed to send multiple packages within the same loop.  Bill hope you don´t mind me pasting code here?

 

RX CODE———————————————

#include <Wire.h>

#include <EasyTransferI2C.h>

 

//create object

EasyTransferI2C ET;

 

struct RECEIVE_DATA_STRUCTURE{

//put your variable definitions here for the data you want to receive

//THIS MUST BE EXACTLY THE SAME ON THE OTHER ARDUINO

int DATA_ID;

int DATA1;

int DATA2;

int DATA3;

};

 

//give a name to the group of data

RECEIVE_DATA_STRUCTURE mydata;

 

//define slave i2c address

#define I2C_SLAVE_ADDRESS 9

 

void setup(){

Serial.begin(9600);

Wire.begin(I2C_SLAVE_ADDRESS);

//start the library, pass in the data details and the name of the serial port. Can be Serial, Serial1, Serial2, etc.

ET.begin(details(mydata), &Wire);

//define handler function on receiving data

Wire.onReceive(receive);

}

 

void loop() {

//check and see if a data packet has come in.

if(ET.receiveData()){

if (mydata.DATA_ID == 1){

Serial.print(“DATA1”);

Serial.println(mydata.DATA1);

Serial.print(“DATA2”);

Serial.println(mydata.DATA2);

Serial.print(“DATA3”);

Serial.println(mydata.DATA3);

// delay(100);

}

if (mydata.DATA_ID == 2){

Serial.print(“DATA4”);

Serial.println(mydata.DATA1);

Serial.print(“DATA5”);

Serial.println(mydata.DATA2);

Serial.print(“DATA6”);

Serial.println(mydata.DATA3);

//  delay(100);

}

}

}

 

void receive(int numBytes) {}

—————————————————————————

 

TX CODE—————————————————————-

#include <Wire.h>

#include <EasyTransferI2C.h>

 

//create object

EasyTransferI2C ET;

 

struct SEND_DATA_STRUCTURE{

//put your variable definitions here for the data you want to send

//THIS MUST BE EXACTLY THE SAME ON THE OTHER ARDUINO

int DATA_ID;

int DATA1;

int DATA2;

int DATA3;

};

 

int SPEED_RAW =0;

int RPM_RAW = 0;

int countup =1;

int testsignal =0;

 

//give a name to the group of data

SEND_DATA_STRUCTURE mydata;

 

//define slave i2c address

#define I2C_SLAVE_ADDRESS 9

 

void setup(){

Wire.begin();

Serial.begin(9600);

Serial.println(“2 wire comms starting…..”);

//start the library, pass in the data details and the name of the serial port. Can be Serial, Serial1, Serial2, etc.

ET.begin(details(mydata), &Wire);

Serial.println(“2 wire comms started OK”);

}

 

void loop(){

Serial.println(“loop started”);

//this is how you access the variables. [name of the group].[variable name]

mydata.DATA_ID = 1;

mydata.DATA1   = 1;

mydata.DATA2   = 2;

mydata.DATA3   = 3;

//send the data

Serial.println(“Sending Data 2 “);

ET.sendData(I2C_SLAVE_ADDRESS);

 

Serial.println(“DATA1  SENT”);

 

delay (5);

 

//this is how you access the variables. [name of the group].[variable name]

mydata.DATA_ID = 2;

mydata.DATA1   = 4;

mydata.DATA2   = 5;

mydata.DATA3   = 6;

//send the data

Serial.println(“Sending Data 2 “);

ET.sendData(I2C_SLAVE_ADDRESS);

 

Serial.println(“DATA2  SENT”);

 

 

delay (5);

}

 

[Anonymous]

Hi John,

Thanks for posting your workaround thats very helpful! I’ll give that a go when I have time.

Many thanks,

 

All the best.

 

Lee

[Anonymous]

y dis serial print is not working.. :/

 

#include <Wire.h>

#include <EasyTransferI2C.h>

const int num = 12;
int print_buffer[num];

//create object

EasyTransferI2C ET;

struct RECEIVE_DATA_STRUCTURE{

//put your variable definitions here for the data you want to receive

//THIS MUST BE EXACTLY THE SAME ON THE OTHER ARDUINO

int DATA_ID;

int DATA1;

int DATA2;

int DATA3;
int DATA4;
int DATA5;
int DATA6;
int DATA7;
int DATA8;
int DATA9;
int DATA10;
int DATA11;
int DATA12;
int DATA13;

};

//give a name to the group of data

RECEIVE_DATA_STRUCTURE sensor_data;

//define slave i2c address

#define I2C_SLAVE_ADDRESS 9

void setup(){

Serial.begin(9600);

Wire.begin(I2C_SLAVE_ADDRESS);

//start the library, pass in the data details and the name of the serial port. Can be Serial, Serial1, Serial2, etc.

ET.begin(details(sensor_data), &Wire);

//define handler function on receiving data

Wire.onReceive(receive);

}

void loop()
{

//check and see if a data packet has come in.

if(ET.receiveData())
{
if (sensor_data.DATA_ID == 1)
{
print_buffer[0] = sensor_data.DATA1;
print_buffer[1] = sensor_data.DATA2;
print_buffer[2] = sensor_data.DATA3;
print_buffer[3] = sensor_data.DATA4;
print_buffer[4] = sensor_data.DATA5;
print_buffer[5] = sensor_data.DATA6;
print_buffer[6] = sensor_data.DATA7;
print_buffer[7] = sensor_data.DATA8;
print_buffer[8] = sensor_data.DATA9;
print_buffer[9] = sensor_data.DATA10;
print_buffer[10] = sensor_data.DATA11;
print_buffer[11] = sensor_data.DATA12;
print_buffer[12] = sensor_data.DATA13;
/*Serial.print(“DATA1”);

Serial.println(sensor_data.DATA1);

Serial.print(“DATA2”);

Serial.println(sensor_data.DATA2);

Serial.print(“DATA3”);

Serial.println(sensor_data.DATA3);

Serial.print(“DATA4”);

Serial.println(sensor_data.DATA4);

Serial.print(“DATA5”);

Serial.println(sensor_data.DATA5);

Serial.print(“DATA6”);

Serial.println(sensor_data.DATA6);

Serial.print(“DATA7”);

Serial.println(sensor_data.DATA7);

Serial.print(“DATA8”);

Serial.println(sensor_data.DATA8);

Serial.print(“DATA9”);

Serial.println(sensor_data.DATA9);

Serial.print(“DATA10”);

Serial.println(sensor_data.DATA10);

Serial.print(“DATA11”);

Serial.println(sensor_data.DATA11);

Serial.print(“DATA12”);

Serial.println(sensor_data.DATA12);

Serial.print(“DATA13”);

Serial.println(sensor_data.DATA13);

// delay(100);*/
for(int i=0;i<=num;i++)
{
if(i == num)
Serial.println(print_buffer[i]);
else
{
Serial.print(print_buffer[i]);
Serial.print(‘\t’);
}
}
}

}

}

void receive(int numBytes) {}

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