I2C (Inter-Integrated Circuit)

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I2C (Inter-Integrated Circuit)#

I2C is a serial communication protocol, so data is transferred bit by bit along a single wire (the SDA line). The SCL line is used to synchronize the data transfer. The I2C protocol is a master-slave protocol, which means that the communication is always initiated by the master device. A master device can communicate with one or multiple slave devices.

Note

The microcontroller use bit banging to communicate with the I2C devices.

All pin configurations are defined in the config.h file. The I2C pins are defined as follows

Table 3 I2C Pinout#

PIN

I2C 1

I2C 2

SDA

P15

P31

SCLK

P32

P30

SSD1306 Display#

The OLED display is a 128x64 pixel monochrome display that uses the I2C protocol for communication.

ssd1306 display

Fig. 15 SSD1306 Display#

The following code snippet shows how to initialize the OLED display and print a message on the screen:

void beep(void) {
uint8_t i;
for(i=255; i; i--) {
    PIN_low(PIN_BUZZER);
    DLY_us(125);
    PIN_high(PIN_BUZZER);
    DLY_us(125);
}
}

void main(void) {
// Setup
CLK_config();                           // configure system clock
DLY_ms(5);                              // wait for clock to stabilize

OLED_init();                            // init OLED

OLED_print("*  UNITelectronics  *");
OLED_print("---------------------\n");
OLED_print("Ready\n");
beep();
while(1) {

}
}

Tip

Remember to includes library corresponding to the OLED display in the file.

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