I2C slave clock stretching

[kyc]

Posted on July 21, 2014 at 09:43

Hi everyone I am Khai.

Currently I am working with STM32F103ZE. I would like to test on clock stretching by using a delay()-function. But seems like it doesn't work. Any advice or suggestion on how to make a test for clock stretching? Belows are my written code:

INIT

void I2C_Initi (I2C_TypeDef *i2cx, int OwnAddress, I2C_Callback_t *callWr, I2C_Callback_t *callRd) {     I2C_InitTypeDef  I2C_InitStructure;     NVIC_InitTypeDef NVIC_InitStructure;     uint32_t clock_en;     callbackWr = callWr;     callbackRd = callRd;     switch((unsigned int)i2cx) {     case (unsigned int)I2C1: clock_en = RCC_APB1Periph_I2C1; break;     case (unsigned int)I2C2: clock_en = RCC_APB1Periph_I2C2; break;     default:         printf(''I2C_Initi bad i2cx %p'',i2cx );         return;         break;     }     RCC_APB1PeriphClockCmd(clock_en, ENABLE);     I2C_StructInit(&I2C_InitStructure);     I2C_InitStructure.I2C_ClockSpeed = 100000;     I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;     I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2;     I2C_InitStructure.I2C_OwnAddress1 = OwnAddress;     I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;     I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;     I2C_Init(i2cx, &I2C_InitStructure);     I2C_ITConfig(i2cx, I2C_IT_BUF|I2C_IT_EVT|I2C_IT_ERR, ENABLE);     I2C_Cmd(i2cx, ENABLE);     I2C_StretchClockCmd(i2cx, ENABLE);     // configure NVIC I2C interrupt     NVIC_InitStructure.NVIC_IRQChannel = I2C2_EV_IRQn;     NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x01;     NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;     NVIC_Init(&NVIC_InitStructure);     NVIC_InitStructure.NVIC_IRQChannel = I2C2_ER_IRQn;     NVIC_Init(&NVIC_InitStructure); }

INTERRUPT HANDLER

void I2C2_EV_IRQHandler(void) {     uint32_t event;     //I2C_StretchClockCmd(I2C2, ENABLE);     //delay_us(I2C_Delay);     event = I2C_GetLastEvent(I2C2);     switch(event) {     // sending to MASTER     case I2C_EVENT_SLAVE_TRANSMITTER_ADDRESS_MATCHED:         I2C_SendData(I2C2, i2c_buf_tx[0]);         tx_count=1;         break;     case I2C_EVENT_SLAVE_BYTE_TRANSMITTED:         I2C_SendData(I2C2, i2c_buf_tx[tx_count]);         tx_count++;         if(tx_count>=i2c_send_len-1)             GPIO_S(gpios+GPO_HOOK_PTT, 0);         break;     case I2C_EVENT_SLAVE_ACK_FAILURE:         /// tell main loop it is done, for example setting i2c_send_len to 0         if(callbackRd)             callbackRd(tx_count, (uint8_t*)i2c_buf_tx);         tx_count=0;         break;         // receiving from MASTER     case I2C_EVENT_SLAVE_RECEIVER_ADDRESS_MATCHED:         I2C_StretchClockCmd(I2C2, ENABLE);        delay_us(I2C_Delay) ; // delay 20 us         //i2c_buf_rx[0]=I2C_ReceiveData(I2C2);         //rx_count=1;         break;     case I2C_EVENT_SLAVE_BYTE_RECEIVED:         delay_us(I2C_Delay); // delay 20 us         //I2C_StretchClockCmd(I2C2, ENABLE);         i2c_buf_rx[rx_count]=I2C_ReceiveData(I2C2);         rx_count++;         break;     case I2C_EVENT_SLAVE_STOP_DETECTED:           delay_us(I2C_Delay); // delay 20 us         //I2C_StretchClockCmd(I2C2, ENABLE);         if(callbackWr)             callbackWr(rx_count, (uint8_t*)i2c_buf_rx);         I2C_AcknowledgeConfig(I2C2, ENABLE);         rx_count=0;         break;     default:         err_count++;         err_event = event;         break;     }     last_event = event; } Thank you. #i2c-stm32