Posted on June 05, 2018 at 20:27hello everybodys , i'm trying to program stm32f072 from stm's bootloader through i2c interface. the stm32f072 is the slave board while the another MCU is the Host/Master board. The host Board use the Simulate i2c on the 2 GPIO connected to SDA and SCL in the stm32f072. I' have a problem. the slave board return always 0x00 when i try to send bootloader's command. What's the correct i2c sequence to be sent from master to slave ? I use for example this sequence:
Master board :
I2C_Start_Bit();
Send_Byte(0X77); //Address slave 0x3B + 1 bit write
ACK();
Send_Byte(0X00);
//command bootloader
ACK();
Send_Byte(0xFF); //command bootloader
ACK();
data[0] = Read_Byte(); //return 0x00 from slave
ACK();
data[1] = Read_Byte();
//return 0x00 from slave
ACK();
data[2] = Read_Byte();
//return 0x00 from slave
NACK();
I2C_Stop_Bit();
i tried to change read/write bit at top, but nothing.
i tried use different combination sequence but nothing.
the ACK return from the slave is correct !
I set the Boot0 pin 1 and nBot0 bit at 1
the level protection is 0
why cannot i read the correct returned command ?
the function are correct because i'm monitoring them through logic analyzer level.
thank you all and sorry for the bad english
