Arduino and STM8 I2C Communication

Question

I want to I2C communication stm8s(slave) and arduino uno(master), but it does not work.

Arduino Uno(master) code:

void setup() {
 Wire.begin(); // join i2c bus (address optional for master)
}
void loop() {
 Wire.beginTransmission(0x30); // transmit to device #0x30
 Wire.write(0x15); // sends one byte
 Wire.endTransmission(); // stop transmitting
 delay(500);
}

STM8 Slave Code with peripheral library: main.c

CLK_HSIPrescalerConfig(CLK_PRESCALER_HSIDIV1);
I2C_DeInit();
I2C_Init(100000, SLAVE_ADDRESS, I2C_DUTYCYCLE_2, I2C_ACK_CURR, I2C_ADDMODE_7BIT, 16);
char veri_bas[1];
while (1)
{
I2C_GenerateSTART(ENABLE);
/* Disable Acknowledgement */
I2C_AcknowledgeConfig(I2C_ACK_NEXT);
/* Send STOP Condition */
I2C_GenerateSTOP(ENABLE);
uint8_t gelen = I2C_ReceiveData();
//uint8_t gelen = 0x15;
sprintf(veri_bas ,"%d" ,gelen);
sendstring(veri_bas);
}

STM8 - main.h:

#ifndef __MAIN_H
#define __MAIN_H
#define I2C_SPEED 100000
#define SLAVE_ADDRESS 0x30
#endif /* __MAIN_H */

Arduino sends data, i saw it on the ossiloscope. Pinout(SCL-SDA-GND) and I2C resistors are correct. Sendstring function is correct. But it does not work. Thank you!

• brhans: Why is your STM8 slave code generating starts & stops?!? That's the master's job.

Answer 1

Your slave should not generate START and STOP events. It must wait for and respond to them appropriately.