I am using the stm8l151... mcu and I am trying to send different strings via Uart1 to HTerminal. I have three different strings to send. The first two strings are transmitted completely but when the third one is being sent, it is truncated and it starts to send the first and second string again and repeatedly but when i go step by step through the code then it works perfectly fine. But if i allow the code to run, then the problem occurs.
I have attached the output from Hterm (uart_com) for better understanding and also some parts of my code(uart transmit and uart_init)
Just for better understanding of the attached output, the strings(cmd 1, 2 and 3) are at+nrb, at+cfun=1, and at+cops=1,2,"26201"
Please, Any suggestion will be greatly appreciated.😊
void nbiot_buf_transmit(void){
for(int i=0 ; i < sizeof(cmd1);i++){
USART_SendData8(USART1,((uint8_t)cmd1[i]));
while(!(USART1->SR));
while(USART_GetFlagStatus(USART1,USART_FLAG_TXE)==RESET);
}
for(int i=0 ; i < sizeof(cmd2);i++){
USART_SendData8(USART1,((uint8_t)cmd2[i]));
while(!(USART1->SR));
while(USART_GetFlagStatus(USART1,USART_FLAG_TXE)==RESET);
}
for(int i=0 ; i < sizeof(cmd3);i++){
USART_SendData8(USART1,((uint8_t)cmd3[i]));
while(!(USART1->SR));
while(USART_GetFlagStatus(USART1,USART_FLAG_TXE)==RESET);
}
void uart_init(void){
/* init Tx and Rx Pins */
GPIO_Init(GPIOC, GPIO_Pin_3, GPIO_Mode_Out_PP_High_Fast); //tx pin output
GPIO_Init(GPIOC, GPIO_Pin_2, GPIO_Mode_In_FL_No_IT); //rx pin input
/* enable usart1 clk */
(CLK->PCKENR1 |= (uint8_t)((uint8_t)1 << ((uint8_t)CLK_Peripheral_USART1 &
(uint8_t)0x0F)));
/* config for GPIO mode */
(CLK->PCKENR2 |= (uint8_t)((uint8_t)1 << ((uint8_t)CLK_Peripheral_COMP &
(uint8_t)0x0F)));
(RI->IOCMR3 &= 0xFD);
(RI->IOSR3 &= (uint8_t) (~(uint8_t) ((uint8_t)1 << (uint8_t) (RI_IOSwitch_6
& (uint8_t) 0x0F))));
(CLK->PCKENR2 &= (uint8_t)(~(uint8_t)(((uint8_t)1 <<
((uint8_t)CLK_Peripheral_COMP & (uint8_t)0x0F)))));
/* init usart peripheral */
USART_Init(USART1,
(PAL_dwCLK_FREQ_VALUE/9600),
USART_WordLength_8b,
USART_StopBits_1,
USART_Parity_No,
USART_Mode_Rx); //Rx enable
ITC->ISPR8 &= 0xFC; // Set USART1_RX_IRQn on ITC_PriorityLevel_2
ITC->ISPR7 &= 0x3F; // Set USART1_TX_IRQn on ITC_PriorityLevel_2
/* enable usart1 peripheral */
USART_Cmd(USART1,ENABLE)
}
strings definition
Related
I was trying baremetal programming for STM32L412T6 controller. I got stuck at RTC wakeup interrupt. My code is jumping to while(1) loop without going to the interrupt handler, Below mentioning my code.
int main(void)
{
//LedConfig();
rtc_domain_access();
rtc_init();
initialize_rtc_wakeup();
NVIC_EnableIRQ(RTC_WKUP_IRQn);
/* Loop forever */
for(;;)
{
flag = 1;
}
}
void rtc_domain_access(void)
{
/* Enable Clock for Power interface.*/
RCC->APB1ENR1 |= (1U<<28);
/*Disable backup domain write protection*/
PWR->CR1 |= (1U<<8);
while((PWR->CR1 & (1U<<8))==0);
/*Reset the Backup domain*/
RCC->BDCR |= (1U<<16);
RCC->BDCR &= ~(1U<<16);
/*Enable LSE Clock source and wait until LSERDY bit to set*/
RCC->BDCR |= (1U<<0);
while ((RCC->BDCR & (1U<<1)) == 0);
/*Select LSE as RTC Clock*/
RCC->BDCR |= (1U<<8);
RCC->BDCR &= ~(1U<<9);
/*Enable RTC Clock*/
RCC->BDCR |= (1U<<15);
/*Disable access to RTC registers*/
RCC->APB1ENR1 &= ~(1U<<28);
}
void rtc_init(void)
{
/* Disable the write protection for RTC registers */
RTC->WPR = 0xCA;
RTC->WPR = 0x53;
/* Check if the Initialization mode is set */
if((RTC->ICSR & (1U<<6))==0)
{
/* Set the Initialization mode */
RTC->ICSR |= (1U<<7);
/* Wait till RTC is in INIT state*/
while((RTC->ICSR & (1U<<6))==0);
}
/* Clear RTC_CR FMT, OSEL, POL and TAMPOE Bits */
RTC->CR &= ~(1U<<6); //FMT
RTC->CR &= ~(1U<<20); //POL
RTC->CR &= ~(1U<<21); //OSEL
RTC->CR &= ~(1U<<22); //OSEL
RTC->CR &= ~(1U<<26); //TAMPOE
/* Set RTC_CR register */
RTC->CR &= ~(1U<<6); //FMT bit set as Zero,Hour Format Selected as 24
RTC->CR &= ~(1U<<20); //POL bit set as Zero, Output polarity selected as high.
RTC->CR &= ~(1U<<21); //OSEL[22:21] set as zero, output selection disabled.
RTC->CR &= ~(1U<<22);
/* Configure the RTC PRER */
RTC->PRER = 0xFF; // Synchronus value set as 255
RTC->PRER |= (0x7F<<16); // Asynchronus value set as 127.
/* Exit Initialization mode */
RTC->ICSR &= ~(1U<<7); // Clear INIT bit.
/* If CR_BYPSHAD bit = 0, wait for synchro */
if((RTC->CR & (1U<<5))==0)
{
/* Clear RSF flag */
RTC->ICSR &= ~(1U<<5);
/* Wait the registers to be synchronised */
while((RTC->ICSR & (1U<<5))==0);
}
/* Clear RTC_CR TAMPALRM_PU, TAMPALRM_TYPE and OUT2EN Bits */
RTC->CR &= ~(1U<<29);
RTC->CR &= ~(1U<<30);
RTC->CR &= ~(1U<<31);
/*Set Output type as open drain pullup*/
RTC->CR |= (1U<<30);
/* Enable the write protection for RTC registers */
RTC->WPR = 0xFF;
}
void Pwr_Clear_Flag(void)
{
PWR->SCR = 0x1F;
}
void RTCEx_DeactivateWakeUpTimer(void)
{
/*Disable Write protection for RTC Registers*/
RTC->WPR = 0xCA;
RTC->WPR = 0x53;
/*Disable the Wakeup Timer*/
RTC->CR &= ~(1U<<10);
/*In case of interrupt mode is used, the interrupt source must disabled*/
RTC->CR &= ~(1U<<14);
/* Wait till RTC WUTWF flag is set */
while ((RTC->ICSR & (1U<<2)) == 0);
/* Enable the write protection for RTC registers */
RTC->WPR = 0xFF;
}
void RTCEx_SetWakeUpTimer_IT(uint32_t RTC_WAKEUP_TIME_IN_SECONDS,uint32_t WakeUpAutoClr)
{
/* Disable the write protection for RTC registers */
RTC->WPR = 0xCA;
RTC->WPR = 0x53;
/* Clear WUTE in RTC_CR to disable the wakeup timer */
RTC->CR &= ~(1U<<10);
/* Clear flag Wake-Up */
RTC->SCR = (1U<<2);
/* Poll WUTWF until it is set in RTC_ICSR to make sure the access to wakeup autoreload
counter and to WUCKSEL[2:0] bits is allowed. */
if((RTC->ICSR & (1U<<6))==0)
{
while((RTC->ICSR & (1U<<2))==0);
}
/* Configure the Wakeup Timer counter and auto clear value */
RTC->WUTR |= (RTC_WAKEUP_TIME_IN_SECONDS-1);
RTC->WUTR |= (WakeUpAutoClr<<16);
/* Configure the clock source */
RTC->CR &= ~(1U<<0);
RTC->CR &= ~(1U<<1);
RTC->CR |= (1U<<2);
/* RTC WakeUpTimer EXTI Configuration: Interrupt configuration */
EXTI->IMR1 |= (1U<<20);
EXTI->RTSR1 |= (1U<<20);
/* Configure the Interrupt in the RTC_CR register */
RTC->CR |= (1U<<14);
/* Enable the Wakeup Timer */
RTC->CR |= (1U<<10);
/* Enable the write protection for RTC registers */
RTC->WPR = 0xFF;
}
void initialize_rtc_wakeup(void)
{
RTCEx_DeactivateWakeUpTimer();
Pwr_Clear_Flag();
RTCEx_SetWakeUpTimer_IT(RTC_WAKEUP_TIME_IN_SECONDS,WakeUpAutoClr);
}
void RTC_WKUP_IRQHandler(void)
{
EXTI->PR1 = (1U<<20);
if((RTC->MISR & (1U<<2))!=0)
{
//GPIOB->ODR |= 1<<13;
RTC->SCR |= (1U<<2);
count++ ;
}
}
I tried to make a RTC wakeup interrupt in every 3 seconds, when it occurs I tried to increase the value of variable count, instead of that it goes to the infinite loop and changes the flag value.
The issue is solved, what happened is RTC_WUTR register has reset value 0x0000FFFF before giving my wakeup clock I had to set the register to zero, once I done that my issue is Solved.
I'm trying to read two ADC channels sequentially from my STM32F407ZGT6 using DMA. I'm just trying to get the values from two potentiometers independently on each channel. Although the program doesn't crash, I does not update my variable's value (sensor_val).
I'm using DMA2_Stream0 Channel 0, since I'm using ADC1. For my ADC1, I'm using PB1 (channel 9) and PA1 (channel 1). I tried to follow this tutorial, except that I do not want to trigger my ADC from a timmer just yet, and I've been also checking the example on this question. My ADC callback also never gets called. As far as my understanding goes, the sequence of calls should be:
ADC1->SR EOC --> ADC->CR1 EOCIE --> DMA2_Stream0_IRQHandler() --> dma_ADC_callback()┐
⮤─────────────────────────────────────────────────────────┘
Maybe I do need to include a periodic call to read the ADC?
All the ADC/DMA functions are on their separate .c/.h files. I've already tried to declare sensor_val as a global variable or as an extern variable from the adc.c file, and both give the same result. Here is an approximate mwe of my code:
#include <stdint.h> //uint32_t
#include <stdio.h> //printf
#include "stm32f407xx.h"
#define set(val, pos) ((val) << (pos))
#define msk(size, pos) (((1UL << (size)) - 1UL) << (pos))
static uint32_t sensor_val[2];
static void dma_ADC_callback(void);
void gpio_init(void)
{
RCC->AHB1ENR |= RCC_AHB1ENR_GPIOAEN; //Port A
RCC->AHB1ENR |= RCC_AHB1ENR_GPIOBEN; //Port B
RCC->AHB1ENR |= RCC_AHB1ENR_GPIOCEN; //Port C
RCC->AHB1ENR |= RCC_AHB1ENR_GPIODEN; //Port D
RCC->AHB1ENR |= RCC_AHB1ENR_GPIOFEN; //Port F
RCC->AHB1ENR;
//PORT B
GPIOA->MODER |= set(m,(2)); //ADC || PA1 || ADC123_IN1
GPIOB->MODER |= set(m,(2)); //ADC || PB1 || ADC12_IN9
}
void adc_init(void)
{
/*Enable clock access to ADC*/
RCC->APB2ENR |= RCC_APB2ENR_ADC1EN;
// RCC->APB2ENR |= RCC_APB2ENR_ADC2EN;
// RCC->APB2ENR |= RCC_APB2ENR_ADC3EN;
/* Config ADC parameters*/
/* Regular Sequence Register 3
* Since the sequence starts from
* the back, we need to set channels
* from SQ3[0] to SQ1[19]
*/
ADC1->SQR3 |= set(0b1001,0); //sets channel PB1 (ADC12_IN9) as 1st conversion
ADC1->SQR3 |= set(0b0001,5); //sets channel PA1 (ADC123_IN1) as 2nd conversion
ADC1->SQR1 |= set(0b0001,ADC_SQR1_L_Pos); //tells the channel sequence lenght = 2
/*If using more than one channel
* SCAN is required
*/
ADC1->CR1 |= set(1,ADC_CR1_SCAN_Pos);
/*Adjust ADC sample time
* The resulting frequency is
* APB2/#cycles:
* 000: 3 cycles
* 001: 15 cycles
* 010: 28 cycles
* 011: 56 cycles
* 100: 84 cycles
* 101: 112 cycles
* 110: 144 cycles
* 111: 480 cycles = 42MHz/480 = 87.5kHz
* */
ADC1->SMPR2 |= set(0b111,ADC_SMPR2_SMP0_Pos); //channel 0
ADC1->SMPR2 |= set(0b111,ADC_SMPR2_SMP9_Pos); //channel 9
/*Turn Interruption On*/
ADC1->CR1 |= set(1,ADC_CR1_EOCIE_Pos);
/*Enable ADC*/
ADC1->CR2 |= set(1,ADC_CR2_ADON_Pos);
}
void adc_start_conversion(void)
{
ADC1->CR2 |= set(1,ADC_CR2_EOCS_Pos); //enables multi-channel conversion
ADC1->CR2 |= set(1,ADC_CR2_CONT_Pos); //enables continuous conversion
ADC1->CR2 |= set(1,ADC_CR2_SWSTART_Pos); //starts conversion
}
/*ADC1 DMA2 => DMA2_Ch0_Stream0 and 4*/
/*ADC2 DMA2 => DMA2_Ch1_Stream2 and 3*/
/*ADC3 DMA2 => DMA2_Ch2_Stream0 and 1*/
void dma2_stream0_init(uint32_t memo, uint32_t periph, uint32_t len)
{
/*Enable clock acces to DMA*/
RCC->AHB1ENR |= RCC_AHB1ENR_DMA2EN;
/*Diable DMA2 Stream 0*/
DMA2_Stream0->CR &= ~DMA_SxCR_EN;
/*Clear all interrupt flags of Stream 0*/
DMA1->LIFCR |= DMA_LIFCR_CFEIF0;
DMA1->LIFCR |= DMA_LIFCR_CDMEIF0;
DMA1->LIFCR |= DMA_LIFCR_CTEIF0;
DMA1->LIFCR |= DMA_LIFCR_CHTIF0;
/*Set the source buffer*/ //Memory Address
DMA2_Stream0->M0AR = memo;
/*Set destination buffer*/ //Peripherial Address
DMA2_Stream0->PAR = periph;
/*Set the length*/
DMA2_Stream0->NDTR = len;
/*Set Control options
* Select Stream0_CH0 |
* Prioritu Lvl = High |
* Memory Increment On |
* Circular mode on |
* Direction Per->Mem (0b00)|
* Enable Transfer Complete interrupt
*/
DMA2_Stream0->CR &= ~(DMA_SxCR_CHSEL |
DMA_SxCR_PL |
DMA_SxCR_MSIZE |
DMA_SxCR_PSIZE |
DMA_SxCR_PINC);
DMA2_Stream0->CR |= (set(0,DMA_SxCR_CHSEL_Pos) |
set(2,DMA_SxCR_PL_Pos) |
set(1,DMA_SxCR_MINC_Pos) |
set(1,DMA_SxCR_CIRC_Pos) |
set(0,DMA_SxCR_DIR_Pos) |
set(1,DMA_SxCR_TCIE_Pos)
);
/*Enable direct mode and disable FIFO*/
DMA2_Stream0->FCR = 0;//set(0,DMA_SxFCR_FEIE_Pos);
/*!! Enable DMA1 Stream 6*/
DMA2_Stream0->CR |= set(1,DMA_SxCR_EN_Pos);
/*Enable ADC transmitter DMA*/
ADC1->CR2 |= set(1,ADC_CR2_DMA_Pos);
/*DMA Interrupt enable in NVIC*/
NVIC_EnableIRQ(DMA2_Stream0_IRQn);
}
void DMA2_Stream0_IRQHandler(void)
{
/*Check for transfer complete interrupt*/
if(DMA2->LISR & msk(1,DMA_LISR_TCIF0_Pos))
{
//Clear flag
DMA2->LIFCR |= msk(1,DMA_LIFCR_CTCIF0_Pos);
//Callback
dma_ADC_callback();
}
}
static void dma_ADC_callback(void)
{
printf("[ Readings Pots.: | %li | %li ]\r\n", sensor_val[0], sensor_val[1]);
}
int main(void)
{
/*Setup*/
//clock_init_168(); //SYSCLK = 168MHz, AHB = 84MHz, APB1 = 42MHz, APB2 = 84MHz
//init_systick_MS(SYSTICK_LOAD_VAL_MS);
gpio_init();
dma2_stream0_init((uint32_t)&sensor_val, (uint32_t)&ADC1->DR, 2);
adc_init();
adc_start_conversion(); //continuous conversion
char count = 0;
for(;;)
{
debug_msg("count : %d", __PRETTY_FUNCTION__, count);
delayMS(500);
count++;
}
}
I finally found a way to fix it!
First of all, the ADC has to be enabled before the DMA. With the code above, ADC1->CR2 |= set(1,ADC_CR2_DMA_Pos) wouldn't get set because I was trying to set the DMA before the ADC. Hence, my interruption never got called. The correct order of function calls is:
adc_init();
dma2_stream0_init((uint32_t)&sensor_val, (uint32_t)&ADC1->DR, 2);
adc_start_conversion();
However, after ADC_CR2_DMA was getting set, my callback got called, but only once. So I had to disable DMA selection with ACD1->CR2 = ADC_CR2_DDS, so DMA would issue conversion requests recurrently:
/*Enable ADC transmitter DMA*/
ADC1->CR2 |= (set(1,ADC_CR2_DMA_Pos) | //<<make sure ADC is already enabled
set(1,ADC_CR2_DDS_Pos)); //<<without DDS, the DMA does a single conversion
Once I did that, my callback got called and I was reading data, but only sensor_val[0] was being updated. That was happening because I had PSIZE == 00, which is the value used to set MSIZE in direct mode. Since I'm using DMA for ADC (maximum 12-bit resolution), I changed sensor_val to uint16_t and PSIZE = 0b01:
DMA2_Stream0->CR |= (set(0,DMA_SxCR_CHSEL_Pos) |
set(2,DMA_SxCR_PL_Pos) |
set(1,DMA_SxCR_PSIZE_Pos) | //<<sets MSIZE=PSIZE in direct mode
set(1,DMA_SxCR_MINC_Pos) |
set(1,DMA_SxCR_CIRC_Pos) |
set(0,DMA_SxCR_DIR_Pos) |
set(1,DMA_SxCR_TCIE_Pos));
And voilá!
NOTES
PINC should be kept at reset value for this configuration, otherwise ADC will expect data with more than 16-bits.
If you need slower rates of acquisition, instead of setting DDS, a DMA request function can be created where the DMA bit is reset and set again:
void adc_new_dma_conversion(void)
{
/*DMA has to be reset first
* then re-enabled to generate
* a new DMA request
*/
ADC1->CR2 &= ~set(1,ADC_CR2_DMA_Pos);
ADC1->CR2 |= set(1,ADC_CR2_DMA_Pos);
}
I'm trying to make a custom library for nRF24l01 for a stm32f103 target device, and I am writing code for a primary TX device.
And here I'm trying to read the register contents of nRF by sending the R_REGISTER command along with the address I am looking for, but I'm not able to figure out how to read the data after the R_REGISTER command is transmitted.
And i'm using the standard stm32f10x.h header file which comes along with startup files on Kiel uVision5.
Here are the configurations,
clock setup
RCC->CR |= RCC_CR_HSION; //HSI on
while( !(RCC_CR_HSIRDY & (RCC->CR)) ); //wait till its ready
//clocks for peripherals
RCC->APB2ENR |= RCC_APB2ENR_IOPAEN; //enable clock forport A
RCC->APB2ENR |= RCC_APB2ENR_AFIOEN; //enable clock for alternate functions
RCC->APB2ENR |= RCC_APB2ENR_SPI1EN; //enable clock for SPI1
GPIO setup
these are my custom-defined functions, they just work fine
//GPIO pin setup as alternate function
pin_mode(IOPA, GPIOA, 7, op_50MHz, op_afpp); //MOSI pin as GPIO alternate_pin can run upto 50MHz
pin_mode(IOPA, GPIOA, 6, ip, ip_pupd); //MISO pin as GPIO alternate_pin can run upto 50MHz
pin_mode(IOPA, GPIOA, 5, op_50MHz, op_afpp); //SCK pin as GPIO alternate_pin can run upto 50MHz
pin_mode(IOPA, GPIOA, 4, op_50MHz, op_gppp); //CS pin as GPIO general_puspose_pin can run upto 50MHz
SPI setup
SPI1->CR1 |= SPI_CR1_MSTR; //master mode
SPI1->CR1 |= SPI_CR1_BR_0 | SPI_CR1_BR_1 | SPI_CR1_BR_2; //at 571Kbps, max 31Mbps
SPI1->CR1 |= SPI_CR1_SSI; //Software slave management enabled
SPI1->CR2 |= SPI_CR2_SSOE; //SS o/p enable
SPI1->CR1 |= SPI_CR1_SPE; //turn on the SPI
Im stuck here
uint8_t SPI_read_uint8_t(uint8_t addr){
uint8_t reg_val;
//sending the read command first along with address where we are reading from
delay_us(50);
digital_writepin(GPIOA, 4, LOW);
SPI1->DR = (R_REGISTER | addr); //sending the R_REGISTER command along with address
while( (SPI1->SR) & (SPI_SR_BSY) );
//please help here, how do I read the Register data from MISO pin
uint8_t spi_read_write(uint8_t data)
{
while(SPI1 -> SR & SPI_SR_RXNE) (void)*(volatile uint8_t *)&SPI1 -> DR; //clean the FIFO
*(volatile uint8_t *)&SPI1 -> DR = data;
while(!(SPI1 -> SR & SPI_SR_RXNE));
return *(volatile uint8_t *)&SPI1 -> DR;
}
uint8_t youroperation(uint8_t command, uint16_t *data)
{
uint8_t status;
setCSLine();
status = spi_read_write(command);
*data = spi_read_write(0);
*data |= ((uint16_t)spi_read_write(0)) << 8;
clearCSLine();
return status
}
youroperation will return Sn status register
command parameter means Cn command bits
data will contain the Dx data bits
To read data from SPI slave you need to send dummy bytes because master provides the clock for the slave.
I am trying to query a temperature sensor (TMP007) over an I2C bus using the L011K4's DMA controller. I've managed to get TMP007 to respond with good data, but that data isn't appearing in the buffer array that I pass my I2C DMA receive function.
What I expect to happen is that the I2C hardware is set up by the software in the Init and Read function, then the start condition is generated, the slave's address and register address are sent, then a second start/a restart is sent out followed by the slave's address again, and finally ending with a transmission of two bytes from TMP007 and a stop condition.
The data acquired from the temperature sensor should be appearing in a buffer that is passed into Start_Read (as MemoryBaseAddress), but that data does not appear when viewing the processor in debug mode after the read function has been called.
The Channel 3 transfer complete interrupt is being called, so I know the DMA has activated and managed the RX transfer, but the data doesn't appear in the desired buffer.
Here's an image of the communication being observed by a logic analyzer: https://i.imgur.com/SzySsXl.png
DIO2 is connected to the onboard LED, which tells us that the DMA transfer has completed (it's the only ISR with the LED toggle).
Any help would be greatly appreciated!
STM32L011K4 Datasheet: https://www.st.com/content/ccc/resource/technical/document/datasheet/42/c0/ab/e5/71/7a/47/0b/DM00206508.pdf/files/DM00206508.pdf/jcr:content/translations/en.DM00206508.pdf
STM32L011K4 Reference Manual: https://www.st.com/resource/en/reference_manual/dm00108282-ultralowpower-stm32l0x1-advanced-armbased-32bit-mcus-stmicroelectronics.pdf
void I2C1_DMA_Start_Read(int SlaveAddress, int RegisterAddress, int* MemoryBaseAddress, int BufferSize) {
I2C1->CR1 &= ~I2C_CR1_PE; // Disable I2C1
DMA1_Channel3->CCR &= ~DMA_CCR_EN; // Disable Channel 3 DMA
DMA1_Channel3->CCR &= ~(0x00007FFF); // Channel 3 DMA mask
// Configure DMA Channel 3 for 16 bit memory and peripheral, and other aliased settings (reference manual page 249, 10.4.3)
DMA1_Channel3->CCR |= (0b11 << 12)|(0b01 << 10)|(0b01 << 8)|DMA_CCR_MINC|DMA_CCR_TEIE|DMA_CCR_TCIE;
DMA1_Channel3->CPAR = (uint32_t) &(I2C1->RXDR);
DMA1_Channel3->CMAR = (uint32_t) MemoryBaseAddress;
DMA1_Channel3->CNDTR = (uint16_t) BufferSize;
DMA1_Channel3->CCR |= DMA_CCR_EN; // Activate DMA channel 3
I2C1->CR1 |= I2C_CR1_NACKIE; // Enable no acknowledge interrupt for I2C1
I2C1->CR2 |= ((uint8_t) (SlaveAddress << 1)); // Set up the slave address
I2C1->CR2 &= ~I2C_CR2_RD_WRN; // Master requests a write transfer in order to send the register
I2C1->CR1 |= I2C_CR1_PE|I2C_CR1_RXDMAEN; // Enable I2C1 and RX DMA for I2C1
I2C1->CR2 &= ~(0xFF << I2C_CR2_NBYTES_Pos); // Mask byte count
I2C1->CR2 |= (0x01 << I2C_CR2_NBYTES_Pos); // Transfer one byte (the slave's register address)
while(!(I2C1->ISR & I2C_ISR_TXE)); // Wait until TX data register is empty
I2C1->TXDR = RegisterAddress; // Set the transmit data to the desired register address
I2C1->CR2 |= I2C_CR2_START; // Generate start condition
while(I2C1->CR2 & I2C_CR2_START); // Wait until hardware clears the start bit
while(!(I2C1->ISR & I2C_ISR_TC)); // Wait until hardware clears the transmit complete bit
I2C1->CR2 |= I2C_CR2_RD_WRN; // Master requests a read transfer after sending over the register address
I2C1->CR2 &= ~(0xFF << I2C_CR2_NBYTES_Pos); // Mask byte count
I2C1->CR2 |= (0x02 << I2C_CR2_NBYTES_Pos); // Master looks for two bytes from the slave
I2C1->CR2 |= I2C_CR2_START; // Generate start condition
while(I2C1->CR2 & I2C_CR2_START); // Wait until hardware clears the start bit
return;
}
void DMA1_Channel2_3_IRQHandler() {
if(DMA1->ISR & DMA_ISR_TCIF3) {
GPIOB->ODR ^= 1 << 3; // Toggle the onboard LED as an indicator
I2C1->CR2 |= I2C_CR2_STOP; // Generate stop condition
while(I2C1->CR2 & I2C_CR2_STOP); // Wait until hardware clears the stop bit
DMA1->IFCR |= DMA_IFCR_CTCIF3; // Clear transfer complete interrupt bit
I2C1->CR1 &= ~I2C_CR1_PE; // Disable I2C1
DMA1_Channel3->CCR &= ~DMA_CCR_EN; // Disable Channel 3 DMA
} else if(DMA1->ISR & DMA_ISR_TEIF3) {
I2C1->CR2 |= I2C_CR2_STOP; // Generate stop condition (if I2C comm is already stopped on error, delete this and following line)
while(I2C1->CR2 & I2C_CR2_STOP); // Wait until hardware clears the stop bit
DMA1->IFCR |= DMA_IFCR_CTEIF3; // Clear transfer error interrupt bit
I2C1->CR1 &= ~I2C_CR1_PE; // Disable I2C1
DMA1_Channel3->CCR &= ~DMA_CCR_EN; // Disable Channel 3 DMA
}
return;
}
void I2C1_IRQHandler() {
if(I2C1->ISR & I2C_ISR_NACKF) {
//GPIOB->ODR ^= 1 << 3; // Toggle the onboard LED as an indicator
I2C1->ICR |= I2C_ICR_NACKCF;
}
return;
}
I am having an issue in getting my computer (virtual COM port, to be exact) to communicate with my STM32L053R8T6 (Nucleo) board by DMA and USART. Here is my code for the DMA and USART part:
#include "Device/Include/stm32l0xx.h" // Device header
#include "JB.h"
#include <string.h>
#define PCLK 32000000
#define BAUD 19200
uint8_t stringtosend[] = "test\n";
uint8_t stringtoreceive[] = " ";
void ENABLE_UART_DMA(void){
RCC->AHBENR |= RCC_AHBENR_DMA1EN; //enable periph.clk for DMA1
/**Enabling DMA for transmission
* DMA1, Channel 4 mapped for USART2TX
* USART2 TDR for peripheral address
* stringtosend for data address
* Memory increment, memory to peripheral | 8-bit transfer | transfer complete interrupt**/
DMA1_CSELR->CSELR = (DMA1_CSELR->CSELR & ~DMA_CSELR_C4S) | (4 << (3 * 4));
DMA1_Channel4->CPAR = (uint32_t)&(USART2->TDR);
DMA1_Channel4->CMAR = (uint32_t)stringtosend;
DMA1_Channel4->CCR = DMA_CCR_MINC | DMA_CCR_DIR | DMA_CCR_TCIE;
/**Enabling DMA for reception
* DMA1, Channel 5 mapped for USART2RX
* USART2 RDR for peripheral address
* stringtoreceive for data address
* Data size given
* Memory increment, peripheral to memory | 8-bit transfer | transfer complete interrupt**/
DMA1_CSELR->CSELR = (DMA1_CSELR->CSELR & ~DMA_CSELR_C5S) | (4 << (4 * 4));
DMA1_Channel5->CPAR = (uint32_t)&(USART2->RDR);
DMA1_Channel5->CMAR = (uint32_t)stringtoreceive;
DMA1_Channel5->CNDTR = sizeof(stringtoreceive);
DMA1_Channel5->CCR = DMA_CCR_MINC | DMA_CCR_TCIE | DMA_CCR_EN;
NVIC_SetPriority(DMA1_Channel4_5_6_7_IRQn, 0); //NVIC enabled, max priority, channels 4-7
NVIC_EnableIRQ(DMA1_Channel4_5_6_7_IRQn);
}
void CONFIGURE_UART_PARAM(void){
RCC->IOPENR |= ( 1ul << 0); //Enable GPIOA clock
RCC->APB1ENR |= ( 1ul << 17); //Enable USART#2 clock
GPIOA->AFR[0] &= ~((15ul << 4* 3) | (15ul << 4* 2) ); //Clear PA2,PA3
GPIOA->AFR[0] |= (( 4ul << 4* 3) | ( 4ul << 4* 2) ); //Set PA2,PA3
GPIOA->MODER &= ~(( 3ul << 2* 3) | ( 3ul << 2* 2) ); //Same as above
GPIOA->MODER |= (( 2ul << 2* 3) | ( 2ul << 2* 2) );
USART2->BRR = PCLK/BAUD;
USART2->CR3 = USART_CR3_DMAT | USART_CR3_DMAR; //Enable DMA mode in transmit and receive
/*UART enabled for transmission and reception*/
USART2->CR1 = USART_CR1_TE | USART_CR1_RE | USART_CR1_UE;
while((USART2->ISR & USART_ISR_TC) != USART_ISR_TC)
{
/* add time out here for a robust application */
}
USART2->ICR = USART_ICR_TCCF;
}
void CONFIGURE_EXTI(void){
SYSCFG->EXTICR[0] = ((SYSCFG->EXTICR[0] & 0x0000) | SYSCFG_EXTICR4_EXTI13_PC); //clear EXTICR and set to PC13(B1)
EXTI->FTSR |= EXTI_FTSR_TR13; //falling edge trigger
EXTI->IMR |= EXTI_IMR_IM13; //unmask
NVIC_SetPriority(EXTI4_15_IRQn, 0); //def interrupt
NVIC_EnableIRQ(EXTI4_15_IRQn);
}
/*************************************************************************************************************************************************************************************************************************/
/*************************************************************************************************************************************************************************************************************************/
/*Interrupt Handlers*/
void DMA1_Channel4_5_6_7IRQHandler(void){
if((DMA1->ISR & DMA_ISR_TCIF4) == DMA_ISR_TCIF4){
DMA1->IFCR = DMA_IFCR_CTCIF4; //Clear Channel 4 Transfer Complete flag
}
else if((DMA1->ISR & DMA_ISR_TCIF5) == DMA_ISR_TCIF5){
DMA1->IFCR = DMA_IFCR_CTCIF5; //Clear Channel 5 Transfer Complete flag
DMA1_Channel5->CCR &= ~DMA_CCR_EN;
DMA1_Channel5->CNDTR = sizeof(stringtoreceive);/* Data size */
DMA1_Channel5->CCR |= DMA_CCR_EN;
}
}
void EXTI4_15_IRQHandler(void){
if(!(GPIOC->IDR & (1 << 13))){
/* Clear EXTI 13 flag */
EXTI->PR = EXTI_PR_PIF13;
/* start 8-bit transmission with DMA */
DMA1_Channel4->CCR &= ~DMA_CCR_EN; //channel disable
DMA1_Channel4->CNDTR = sizeof(stringtosend);/* Data size */
DMA1_Channel4->CCR |= DMA_CCR_EN; //channel enable
}
}
//void EXTI4_15_IRQHandler(void){
// if((EXTI->PR & EXTI_PR_PIF13) == EXTI_PR_PIF13){
// /* Clear EXTI 13 flag */
// EXTI->PR = EXTI_PR_PIF13;
//
// /* start 8-bit transmission with DMA */
// DMA1_Channel4->CCR &= ~DMA_CCR_EN; //channel disable
// DMA1_Channel4->CNDTR = sizeof(stringtosend);/* Data size */
// DMA1_Channel4->CCR |= DMA_CCR_EN; //channel enable
// }
//}
Now then, this specific code is based on an example from the STM32L0 snippets package 1.20, USART/Communcation Using DMA. USART 1 was simply redefined to USART 2 (as that is the one used by the virtual COM port), and the DMA channels were redefined according to that as well. However, the problem here is very simple: it will only print stringtosend once (would like to do it every time button B1 is pressed), and will not receive data by RX either - as if it completely ignores the DMA interrupt handler - which I am not sure how to test (no trace features available on this board). What I have seems to reflect the reference manual well enough, and all the main does is:
int main(){
SystemCoreClockInit();
CONFIGURE_UART_PARAM();
ENABLE_UART_DMA();
pushbutton_def();
CONFIGURE_EXTI();
while(1){
}
...which should just react to the defined interrupts, however it does not, and for the life of me, I cannot see why. I would love if you could help me - I would also like to avoid HAL or LL APIs - this is not a complex enough project to warrant their usage (several inputs, outputs, comms between two boards by USART/DMA), plus I would prefer to learn working closer to the register level.
Thanks!
edit (in response to Berendi's suggestions):
1. GPIOC was defined in another file, called with pushbutton_def():
RCC->IOPENR |= (1UL << 2); //enable GPIOC
I understand exactly what you mean by your explanation (indeed, the register referred by those two is "the same", 0x00000020U), but I am not sure as to how to redefine it: here is my attempt after looking at the reference manual (SYSCFG part) and the source (still, it does not work):
SYSCFG->EXTICR[3] = ((SYSCFG->EXTICR[3] & 0x0000) | SYSCFG_EXTICR4_EXTI13_PC);
As suggested, I have added USART2->ICR = USART_ICR_TCCF; to the EXTIhandler, right after the DMA channels. I have kept it in the USART definition. The message is still only being sent once, though.
GPIOC is not enabled
Here,
RCC->IOPENR |= ( 1ul << 0); //Enable GPIOA clock
you should enable GPIOC too.
EXTI13 is mapped to PA13
Here,
SYSCFG->EXTICR[0] = ((SYSCFG->EXTICR[0] & 0x0000) | SYSCFG_EXTICR4_EXTI13_PC); //clear EXTICR and set to PC13(B1)
you are setting the configuration register for EXTI0-EXTI3, actually mapping EXTI1 to PC1. EXTI13 remains mapped to PA13, which is actually SWDIO, connected to the onboard debugger. I guess the traffic on SWDIO triggers the EXTI interrupt, the handler checks PC13 which is always reading 0 because the port is disabled, and enables DMA. DMA transmit works only once though, because
USART_ISR_TC is not cleared in the interrupt
but only once at startup. You should move this line
USART2->ICR = USART_ICR_TCCF;
to the EXTI interrupt handler.
I'm not sure why receiving doesn't work, perhaps the DMA handler has no chance to run, because EXTI is constantly retriggered by SWD traffic. Both interrupts have the same priority, the one with lower interrupt number wins, which is the EXTI handler. If it's always retriggered before it finishes, then it will be called again, not letting the other handler to run.