I am using a Digole Display for the first time.

I interfaced by the i2C pins of an ATMEGA MCU; I have the SDA and SCK.

On the same bus I have other i2C chips, with addresses different from 0x27.

To access to these chips I wrote alwasy a first byte with the address of the chip itself and one (or more) byte with the data.

To access the Digole Display seems the first byte, aka the adrress, is not needed/used

True?

So the Digole Display is not activated by the address first, so the Digolae Display is always on-line, and it capture the i2C bus for it.

True?

Pleas ehelp me to understand how to access the Digole Display when on the sme bus I have other i2C users.

I setup a simple platform, only the MCU, the Digole and a 4x20 alfanumeric LCD.

The MCU board works well with other i2C chips; any other i2C chip is not connected for this test.

So now it is working only the MCU, the LCD 4x20 (parallel mode - for debug only) and the Digole.

The i2C bus clock is set at 100KHz. 

I wrote a very simple code:

int main(void);

lcd_clrscr();

InitTimers();

sei(); // enable interrupts

lcd_puts("MCU ON\n");

i2c_init(); // ATMEGA1284 Joins the I2C bus as a master at 100KHz frequency

lcd_puts(" i2C_initialized\n");

j=i2c_start(0x27);

if(j) lcd_puts("no Digole no\n"); else lcd_puts("Digole OK\n");

while(1) {

Digole_clearScreen();

lcd_puts("ok 2");

Digole_printChar('a');

lcd_puts("OK 3");

wdt_reset();

}

}

At the 4x20 LCD I read "MCU_ON", "i2c_initialized" and then "no Digole no". No reaction by Digole at the j=i2c_start(0x27);

Suggestion?