STM32 how to set a slave I2C port
Solution 1
I had the same problem. It was caused by absence of the required for I2C external pull-up resistors. You can't just use an internal MCU's pull-ups. You MUST use external ones.
Detailed explanation is provided in these articles:
http://www.robot-electronics.co.uk/acatalog/I2C_Tutorial.html
Solution 2
I run into similar issue. In my case the solution was to add a HAL_I2C_EnableListen_IT() after initialization to activate I2C slave (I am using HAL libraries, but you can check what the above function does in details).
![Admin](/assets/logo_square_200-5d0d61d6853298bd2a4fe063103715b4daf2819fc21225efa21dfb93e61952ea.png)
Admin
Updated on June 14, 2022Comments
-
Admin about 2 years
I have an issue with STM32F0 Discovery. I am using I2C1 (like master) to send start condition and address to I2C2 (slave) on the same board. I am able to generate propertly the signal but the IC2 (slave) is not able to generate an ACK on 9th clk
What's wrong? Here my code about the setup:
void set_I2C(void){ GPIO_InitTypeDef GPIO_InitStructure; I2C_InitTypeDef I2C_InitStructure; RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB, ENABLE); RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE); /* Configure the I2C clock source. The clock is derived from the HSI */ RCC_I2CCLKConfig(RCC_I2C1CLK_SYSCLK); GPIO_PinAFConfig(GPIOB, GPIO_PinSource6, GPIO_AF_1); GPIO_PinAFConfig(GPIOB, GPIO_PinSource7, GPIO_AF_1); //Configure pins: SCL and SDA ------------------ GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL; GPIO_InitStructure.GPIO_OType = GPIO_OType_OD; GPIO_Init(GPIOB, &GPIO_InitStructure); I2C_DeInit(I2C1); I2C_Cmd(I2C1, DISABLE); I2C_InitStructure.I2C_AnalogFilter = I2C_AnalogFilter_Enable; I2C_InitStructure.I2C_DigitalFilter = 0x00; I2C_InitStructure.I2C_OwnAddress1 = 0x40; I2C_InitStructure.I2C_Mode = I2C_Mode_I2C; I2C_InitStructure.I2C_Ack = I2C_Ack_Enable; I2C_InitStructure.I2C_Timing =0xB0420F13; //100KHz I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit; I2C_Init(I2C1, &I2C_InitStructure); I2C_Cmd(I2C1, ENABLE); //Set up of I2C2 RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C2, ENABLE); RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB, ENABLE); GPIO_PinAFConfig(GPIOB, GPIO_PinSource11, GPIO_AF_1); GPIO_PinAFConfig(GPIOB, GPIO_PinSource10, GPIO_AF_1); //Configure pins: SCL and SDA ------------------ GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11 | GPIO_Pin_10; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF; GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL; GPIO_InitStructure.GPIO_OType = GPIO_OType_OD; GPIO_Init(GPIOB, &GPIO_InitStructure); I2C_DeInit(I2C2); I2C_Cmd(I2C2, DISABLE); I2C_InitStructure.I2C_AnalogFilter = I2C_AnalogFilter_Disable; I2C_InitStructure.I2C_DigitalFilter = 0x00; I2C_InitStructure.I2C_OwnAddress1 = 0x30; I2C_InitStructure.I2C_Mode = I2C_Mode_I2C; I2C_InitStructure.I2C_Ack = I2C_Ack_Enable; I2C_InitStructure.I2C_Timing =0xB0420F13; I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit; I2C_Init(I2C2, &I2C_InitStructure); I2C_Cmd(I2C2, ENABLE); I2C_ITConfig(I2C2, I2C_AcknowledgedAddress_7bit, ENABLE); NVIC_InitTypeDef NVIC_InitStructure; /* Configure the I2C2 interrupt priority */ NVIC_InitStructure.NVIC_IRQChannel = I2C2_IRQn; NVIC_InitStructure.NVIC_IRQChannelPriority=1; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure);
}