Wire.h override

good day people,

i'm writing in ask question. i've been working on i2c eeprom flasher using arduino (for sake of being able it). , i've stumbled upon size of databuffer being used in wire library. ideally, need able write page page (64 bytes @ time), where-as wire.h library support 30 bytes @ time because buffer declared 32-byte buffer , 2 bytes end being used addressing.

what i've tried following, in copy of wire.h, i've made this:

code: [select]


#define buffer_length 32

#ifdef twi_b_override
#undef buffer_length
#define buffer_length twi_b_override
#endif

so when in arduino sketch #define twi_b_override 66, take value , roll it.. however, @ runtime, i'm not seeing bigger buffer being used , instead writes 30 bytes did before.

the following @ top of arduino sketch btw.

code: [select]

#define twi_b_override 66
#include <wire.h>

any , appreciated in advance.

quote

my copy of wire.h

did change wire.h in arduino distribution or did make own copy , put somewhere else?

what version of arduino using?

hold 'shift' key down , click 'verify' button in arduino.  it tells "include" directories being used , output files stored.  does "-i" stuff show directory in wire.h located?

quote

top of arduino sketch

look @ output file named "yoursketchname.cpp" in indicated directory.

the first lines should like

code: [select]


#define twi_b_override 64
#include <wire.h>
//
// maybe other stuff included in sketch
//
#include "wprogram.h"
void setup();
void loop();
.
.
.


bottom line: made indicated changes in arduino-0021/hardware/arduino/cores/arduino/wire.h , ran following sketch:

code: [select]

#define twi_b_override 64
#include <wire.h>

void setup()
{
   serial.begin(9600);
}
void loop()
{
   serial.print("twi_b_override = ");
   serial.println(twi_b_override);
   serial.print("buffer_length  = ");
   serial.println(buffer_length);
   delay(10000);
}


here's output arduino duemilanove:

---

twi_b_override = 64
buffer_length  = 64

---

regards,

dave

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