I am using stm32f0 MCU.
I would like to transmit every single byte received from the uart out of the uart. I am enabling an interrupt on every byte received from uart.
My code is quite simple.
uint8_t Rx_data[5];
//Interrupt callback routine
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
if (huart->Instance == USART1) //current UART
{
HAL_UART_Transmit(&huart1, &Rx_data[0], 1, 100);
HAL_UART_Receive_IT(&huart1, Rx_data, 1); //activate UART receive interrupt every time on receiving 1 byte
}
}
My PC transmits ASCII 12345678 to stm32. If things work as expected, the PC should be receiving 12345678 back. However, the PC receives 1357 instead. What is wrong with the code?
Reenabling interrupts may be inefficient. With a couple of modifications it is possible to keep the interrupt active without needing to write the handler all over again. See the example below altered from the stm32cubemx generator.
/**
* #brief This function handles USART3 to USART6 global interrupts.
*/
void USART3_6_IRQHandler(void)
{
InterruptGPS(&huart5);
}
void InterruptGPS(UART_HandleTypeDef *huart) {
uint8_t rbyte;
if (huart->Instance != USART5) {
return;
}
/* UART in mode Receiver ---------------------------------------------------*/
if((__HAL_UART_GET_IT(huart, UART_IT_RXNE) == RESET) || (__HAL_UART_GET_IT_SOURCE(huart, UART_IT_RXNE) == RESET)) {
return;
}
rbyte = (uint8_t)(huart->Instance->RDR & (uint8_t)0xff);
__HAL_UART_SEND_REQ(huart, UART_RXDATA_FLUSH_REQUEST);
// do your stuff
}
static void init_gps() {
__HAL_UART_ENABLE_IT(&huart5, UART_IT_RXNE);
}
You should make a tx array buffer as well, and use interrupt for writing as well (The first write if not enabled yet, should be sent immediately).
There should be examples of this for STM32 around.
You should probably switch the two lines: Transmit and Receive. The Transmit function waits for a timeout to send the character, in meantime the next received character is missed.
Related
I want to send 10 bytes of data through UART loopback by interrupt mode. Though I'm able to receive the data, I don't understand why my HAL_UART_RxCpltCallback() is not getting executed. But my HAL_UART_TxCpltCallback(), is getting executed every time after a byte of data is transferred. I've generated code through cubeMX. I've enabled the USART2 global interrupt. My Control Register(CR1) for my USART2 is 0x300c. That is, UE,M,TE,RE bits are only set. The TXIE, TCIE bits are NOT set in the CR1 Register.
Now,
What does "global" in global interrupt mean here? Does that mean an interrupt is generated from any one of the 10 sources(mentioned in the data sheet like, Tx complete, Rx buffer full etc)?
None of the bits corresponding to interrupts are enabled in CR1 register. But the control is going to HAL_UART_TxCpltCallback() every time it transfers a byte of data. Why does this happen?
Please unveil the mystery.
PS: I'm using STM32F407G-DISC1 board, Attolic Truestudio IDE, Ubuntu 16.04 OS.
UART_HandleTypeDef huart2;
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART2_UART_Init(void);
uint8_t tx_data[] = {0,1,2,3,4,5,6,7,8,9};
uint8_t rx_data[10];
int main(void)
{
int i=0;
HAL_Init();
SystemClock_Config();
MX_GPIO_Init();
MX_USART2_UART_Init();
while (1)
{
HAL_UART_Transmit_IT(&huart2, &tx_data[i], 10);
HAL_Delay(1500);
HAL_UART_Receive_IT(&huart2, &rx_data[i] , 10);
HAL_Delay(1500);
if((xferCnt==10) || (rxCnt==10))
break;
else
i++;
}
}
void HAL_UART_TxCpltCallback(UART_HandleTypeDef *huart)
{
xferCnt++;
}
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
rxCnt++;
}
I'm communicating my C# applications with dsPIC x16 microcontroller using UART. I want to send/receive fixed size frames and I tried to manage it in a following way:
if(readFrame)
{ IEC0bits.U1RXIE=0; //turn off the U1RX interrupts
readFrame = false;
while(indexer < 8 )
{
while(!U1STAbits.URXDA);
modbusBuffer[indexer]=U1RXREG;
indexer++;
}
if(indexer == 8)
{
modbusRecvTask(modbusBuffer);
indexer=0;
}
IEC0bits.U1RXIE=1; //turn on U1RX interrupts
}
void _ISR_NAP _U1RXInterrupt()
{
if(IFS0bits.U1RXIF)
{
IFS0bits.U1RXIF = 0; //set the interrupt flag to false
if(U1STAbits.OERR==1) //check overload error
{
U1STAbits.OERR=0; //clear error flag
}
else
{
readFrame = true;
}
}
}
The thing is that it works fine only for the first received frame. After that the program goes into the receiver interrupt again and sets the flag readFrame to true even though no bytes were send and is getting stuck in line:
while(!U1STAbits.URXDA);
I've read some advices to clear the read buffer of the UART in order to prevent the program to go into the ISR again but I couldn't find a way to do it.
I've bought an STM32F411 nucleo board and now I'm trying to understand various bits and pieces of the HAL. Starting with external interrupts seemed to be a good idea, because the board has a push button which is connected to PC13. So I've set up a simple toggle-the-frequency blinky. The code below is a bit simplified:
#define LED_PIN GPIO_PIN_5
#define BTN_PIN GPIO_PIN_13
static uint32_t blink_period = 250;
int main(void)
{
HAL_Init();
SystemClock_Config();
__GPIOA_CLK_ENABLE();
GPIO_InitTypeDef pinConfig;
pinConfig.Pin = (LED_PIN);
pinConfig.Pull = GPIO_NOPULL;
pinConfig.Mode = GPIO_MODE_OUTPUT_PP;
pinConfig.Speed = GPIO_SPEED_FAST;
HAL_GPIO_Init(GPIOA, &pinConfig);
__GPIOC_CLK_ENABLE();
pinConfig.Pin = (BTN_PIN);
pinConfig.Pull = GPIO_NOPULL;
pinConfig.Mode = GPIO_MODE_IT_FALLING;
pinConfig.Speed = GPIO_SPEED_LOW;
HAL_GPIO_Init(GPIOC, &pinConfig);
HAL_NVIC_SetPriority(EXTI15_10_IRQn, 0x0F, 0x00);
HAL_NVIC_EnableIRQ(EXTI15_10_IRQn);
while (1)
{
HAL_GPIO_TogglePin(GPIOA, LED_PIN);
HAL_Delay(blink_period);
}
}
void EXTI15_10_IRQHandler(void)
{
HAL_GPIO_EXTI_IRQHandler(BTN_PIN);
}
void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin)
{
if(GPIO_Pin == BTN_PIN)
{
if (blink_period == 500)
{
blink_period = 250;
}
else
{
blink_period = 500;
}
}
}
When I push the button, an interrupt is generated and the blinky frequency changes from 1 to 2 Hz (or vice-versa). This works as intended, but why? I forgot to clear the pending interrupt flag, so the ISR should be called over and over. The datasheet clearly states that
When the selected edge occurs on the external interrupt line, an interrupt request is generated. The pending bit corresponding to the interrupt line is also set. This request is
reset by writing a ‘1’ in the pending register.
Reading a bit further reveals that this is a bit different for events:
When the selected edge occurs on the event line, an event pulse is generated. The pending bit corresponding to the event line is not set.
However, I'm not setting the button pin mode to any of the GPIO_MODE_EVT_... modes so I'm not using the event mechanism (to be honest I don't yet know what that even is - I just think that I'm not using it. Any hints are welcome).
So somewhere I should have to call void HAL_NVIC_ClearPendingIRQ (IRQn_Type IRQn), shouldn't I? It seems that clearing the flag by software is not necessary, because the ISR is not called more than once per falling edge. I've added a breakpoint in HAL_GPIO_EXTI_Callback to verify this.
Edit
As mentioned in the comments, the flag clearing code is in ST's implementation of the GPIO interrupt handler:
void HAL_GPIO_EXTI_IRQHandler(uint16_t GPIO_Pin)
{
/* EXTI line interrupt detected */
if(__HAL_GPIO_EXTI_GET_IT(GPIO_Pin) != RESET)
{
__HAL_GPIO_EXTI_CLEAR_IT(GPIO_Pin);
HAL_GPIO_EXTI_Callback(GPIO_Pin);
}
}
This handler needs to be called by the actual ISR (which is done in my code) and it clears the pending flag corresponding to the GPIO_Pin argument. So I have to write an ISR which sorts out which flags are set, and call HAL_GPIO_EXTI_IRQHandler for each, which in turn calls my HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin), again with the pin as an argument. For each external interrupt, the pin number would get checked some ~3 times (in the ISR, in the handler and in the callback)!
If that is the solution, I want my problem back.
You don't have to call HAL_NVIC_ClearPendingIRQ (IRQn_Type IRQn) because the pending bit in the NVIC will be cleared automatically upon entering HAL_GPIO_EXTI_IRQHandler.
The HAL_GPIO_EXTI_IRQHandler() implementation clears the pending bit in the peripheral, not in the NVIC. If it didn't clear the pending bit by calling __HAL_GPIO_EXTI_CLEAR_IT(GPIO_Pin), then the handler would be called again and again. The point is that you must distinguish between the interrupt pending bit in the peripheral and the pending bit in the NVIC.
I'm trying to set up an external interrupt on my LPC812 uC. I've made the following code
#include "LPC8xx.h"
#define RLED 7 // red LED
bool pause = false;
void PININT0_IRQHandler(void)
{
pause = !pause;
}
int main(void) {
LPC_GPIO_PORT->DIR0 |= 1<<RLED; // set pin as output
LPC_GPIO_PORT->SET0 = 1<<RLED;
NVIC_EnableIRQ(PININT0_IRQn);
while (1)
{
if(!pause)
{
LPC_GPIO_PORT->CLR0 = 1<<RLED;
}
}
}
But it isn't working. Am I missing something?
I'm not familiar with NXP MCUs.
But at least place break piont inside PININT0_IRQHandler, to understand clearly that interrupt is not generated.
Also it will be nice to clear interrupt flag inside handler.
Some peripherals need interrupt permission in peripheral registers in addition to NVIC setup.
Did you setup input pin somewhere?
Your code only initialize GPIO 7 pin as output.
I try to implement a i2c slave receiver interrupt service routine on a stm32f4.
Here is my smart piece of code.
void I2C2_EV_IRQHandler()
{
switch (I2C_GetLastEvent(I2C2))
{
//The address sent by the master matches the own address of the peripheral
case I2C_EVENT_SLAVE_RECEIVER_ADDRESS_MATCHED:
//The slave stretches SCL low until ADDR is
//cleared and DR filled with the data to be sent
I2C_ClearFlag(I2C2,I2C_FLAG_ADDR);
break;
//The application is expecting a data byte to be received
case I2C_EVENT_SLAVE_BYTE_RECEIVED:
I2C_ReceiveData(I2C2);
break;
//The application is expecting the end of the communication
//Make sure that both ADDR and STOPF flags are cleared
//if both are found set.
case I2C_EVENT_SLAVE_STOP_DETECTED:
if(I2C_GetFlagStatus(I2C2,I2C_FLAG_ADDR) == SET)
I2C_ClearFlag(I2C2,I2C_FLAG_ADDR);
if(I2C_GetFlagStatus(I2C2,I2C_FLAG_STOPF) == SET)
I2C_ClearFlag(I2C2,I2C_FLAG_STOPF);
}
}
The interrupt becomes called and I2C_EVENT_SLAVE_RECEIVER_ADDRESS_MATCHED case is entered.
The SCL is low now. The reference manual says if I clear the address flag, the clock will continue and data will be sent (Page 579 - Slave receiver). In my opinion the interrupt always becomes called if any data arrives and next state will be I2C_EVENT_SLAVE_BYTE_RECEIVED.
I can not find any example from stm or via google. Can anybody help me or show me an example.
now it works. My problem was that I was not able to reset the ADDR and the STOPF register with the given commands out of reference manual. But if do it in a loop it works fine for me. Here my working Interrupt Routine.
void I2C3_EV_IRQHandler()
{
switch (I2C_GetLastEvent(I2C3))
{
case I2C_EVENT_SLAVE_RECEIVER_ADDRESS_MATCHED:
STM_EVAL_LEDOn(LED3);
STM_EVAL_LEDOff(LED5);
break;
case I2C_EVENT_SLAVE_BYTE_RECEIVED:
STM_EVAL_LEDToggle(LED4);
STM_EVAL_LEDOff(LED3);
I2C_InputBuffer[I2C_InputBufferIndex++] = I2C_ReceiveData(I2C3);
break;
case I2C_EVENT_SLAVE_STOP_DETECTED:
STM_EVAL_LEDOn(LED6);
STM_EVAL_LEDOff(LED4);
break;
}
I2C_CleanADDRandSTOPF();
if(I2C_InputBufferIndex > MOTOR_PACKAGE_SIZE-1)
{
motorHandleEvent(I2C_InputBuffer);
I2C_InputBufferIndex = 0;
uint8_t resetIndex;
for(resetIndex = 0; resetIndex < MOTOR_PACKAGE_SIZE; resetIndex ++)
I2C_InputBuffer[resetIndex] = 0;
}
}
inline void I2C_CleanADDRandSTOPF()
{
while ((I2C3->SR1 & I2C_SR1_ADDR) == I2C_SR1_ADDR)
{
volatile uint32_t temp;
temp=I2C3->SR1;
temp=I2C3->SR2;
}
while ((I2C3->SR1&I2C_SR1_STOPF) == I2C_SR1_STOPF)
{
volatile uint32_t temp;
temp=I2C3->SR1;
I2C3->CR1 |= 0x1;
}
}
The hardware is doing clock stretching to ensure that the slave is keeping up with the master. The slave first waits to get an address match. Then you get interrupt while SCL is held low. This allows slave to basically provide flow control to the master. The master detects that SCL is being held low by slave and it will wait for it to be released before master sends any more data. So you won't get additional interrupts on data being received because the master won't send any more data until you let SCL go high. You can read about clock stretching here http://en.wikipedia.org/wiki/I%C2%B2C