An error occurred in the communication between the stm32f103c8t6 and python smbus #1436
Description
The code I tested is below.
python code:
import smbus
bus = smbus.SMBus(1)
# Read a block of 6 bytes from address 0x18, offset 0
data = bus.read_i2c_block_data(0x18, 0, 6)
arduino code:
#include <Wire.h>
#define I2C_ADDR 0x18
void setup()
{
Wire.begin(I2C_ADDR); // join i2c bus with address #0x18
Wire.onRequest(requestEvent); // register event
Wire.onReceive(receiveEvent); // register event
Serial.begin(115200); // start serial for output
}
void loop()
{
//empty loop
}
// function that executes whenever data is received from master
// this function is registered as an event, see setup()
void receiveEvent(int howMany)
{
while(0 < Wire.available()) // loop through all but the last
{
char c = Wire.read(); // receive byte as a character
Serial.print(c); // print the character
}
int x = Wire.read(); // receive byte as an integer
Serial.println(x); // print the integer
}
// function that executes whenever data is requested by master
// this function is registered as an event, see setup()
void requestEvent()
{
Wire.write("hello\n"); // respond with message of 6 bytes
// as expected by master
}
Test Results：
The code was successfully uploaded to stm32 without errors. When I run the python smbus code, 6 bytes of data were successfully read, but I did not see any information on the serial monitor.
I changed my bluepill to arduino nano for testing and the code runs successfully. The difference is that I saw the print data from the serial monitor. The printed data is exactly the offset parameter in the smbus code.
bus.read_i2c_block_data(address, offset, data size)
In other words, the problem with stm32 i2c is that the offset parameter of smbus cannot be obtained.