/**
* @brief Configures TIM5 to measure the LSI oscillator frequency.
* @param None
* @retval LSI Frequency
*/
static uint32_t GetLSIFrequency(void)
{
TIM_IC_InitTypeDef TIMInput_Config;
/* Configure the TIM peripheral *********************************************/
/* Set TIMx instance */
Input_Handle.Instance = TIM5;
/* TIM5 configuration: Input Capture mode ---------------------
The LSI oscillator is connected to TIM5 TIM_CHANNEL_4.
The Rising edge is used as active edge.
The TIM5 CCR TIM_CHANNEL_4 is used to compute the frequency value.
------------------------------------------------------------ */
Input_Handle.Init.Prescaler = 0;
Input_Handle.Init.CounterMode = TIM_COUNTERMODE_UP;
Input_Handle.Init.Period = 0xFFFF;
Input_Handle.Init.ClockDivision = 0;
if(HAL_TIM_IC_Init(&Input_Handle) != HAL_OK)
{
/* Initialization Error */
Error_Handler();
}
/* Connect internally the TIM5 TIM_CHANNEL_4 Input Capture to the LSI clock output */
__HAL_RCC_AFIO_CLK_ENABLE();
__HAL_AFIO_REMAP_TIM5CH4_ENABLE();
/* Configure the Input Capture of TIM_CHANNEL_4 */
TIMInput_Config.ICPolarity = TIM_ICPOLARITY_RISING;
TIMInput_Config.ICSelection = TIM_ICSELECTION_DIRECTTI;
TIMInput_Config.ICPrescaler = TIM_ICPSC_DIV8;
TIMInput_Config.ICFilter = 0;
if(HAL_TIM_IC_ConfigChannel(&Input_Handle, &TIMInput_Config, TIM_CHANNEL_4) != HAL_OK)
{
/* Initialization Error */
Error_Handler();
}
/* Start the TIM Input Capture measurement in interrupt mode */
if(HAL_TIM_IC_Start_IT(&Input_Handle, TIM_CHANNEL_4) != HAL_OK)
{
Error_Handler();
}
/* Wait until the TIM5 get 2 LSI edges */
while(uwCaptureNumber != 2)
{
}
/* Disable TIM5 CC1 Interrupt Request */
HAL_TIM_IC_Stop_IT(&Input_Handle, TIM_CHANNEL_4);
/* Deinitialize the TIM5 peripheral registers to their default reset values */
HAL_TIM_IC_DeInit(&Input_Handle);
return uwLsiFreq;
}
void DHT22_InterruptHandler(DHT22_HandleTypeDef* handle) {
uint16_t val = HAL_TIM_ReadCapturedValue(&handle->timHandle,
handle->timChannel);
uint32_t freq = HAL_RCC_GetPCLK2Freq();
uint16_t val2;
if (val > handle->lastVal)
val2 = val - handle->lastVal;
else
val2 = 65535 + val - handle->lastVal;
handle->lastVal = val;
float time = 1000000.0 * val2 / freq;
if (handle->bitPos < 0) {
if (time > 155.0 && time < 165.0) {
handle->bitPos = 0;
}
} else if (handle->bitPos >= 0 && handle->bitPos < 40) {
if (time > 78.0 && time < 97.0) {
handle->bitsRX[handle->bitPos / 8] &= ~(1
<< (7 - handle->bitPos % 8));
handle->bitPos++;
} else if (time > 120.0 && time < 145.0) {
handle->bitsRX[handle->bitPos / 8] |= 1 << (7 - handle->bitPos % 8);
handle->bitPos++;
} else {
handle->bitPos = -1;
HAL_TIM_IC_Stop_IT(&handle->timHandle, handle->timChannel);
handle->state = DHT22_READY;
}
}
if(handle->bitPos==40){
handle->bitPos = -1;
//TODO This was changed (commented out) recently i'm not sure why
HAL_TIM_IC_Stop_IT(&handle->timHandle, handle->timChannel);
uint8_t sum = 0;
for (int i = 0; i < 4; i++) {
sum += handle->bitsRX[i];
}
if (sum == handle->bitsRX[4]) {
handle->crcErrorFlag = 0;
int16_t temp10 = 0;
if ((handle->bitsRX[2] & 0x80) == 0x80) {
temp10 |= (handle->bitsRX[2] & 0x7F) << 8;
temp10 |= handle->bitsRX[3];
temp10 *= -1;
} else {
temp10 |= handle->bitsRX[2] << 8;
temp10 |= handle->bitsRX[3];
}
handle->temp = 0.1 * temp10;
int16_t hum10 = 0;
if ((handle->bitsRX[0] & 0x80) == 0x80) {
hum10 |= (handle->bitsRX[0] & 0x7F) << 8;
hum10 |= handle->bitsRX[1];
hum10 *= -1;
} else {
hum10 |= handle->bitsRX[0] << 8;
hum10 |= handle->bitsRX[1];
}
handle->hum = 0.1 * hum10;
} else {
handle->crcErrorFlag = 1;
}
handle->state = DHT22_RECEIVED;
}
}
/**
* @brief Configures TIM14 to measure the LSI oscillator frequency.
* @param None
* @retval LSI Frequency
*/
static uint32_t GetLSIFrequency(void)
{
TIM_IC_InitTypeDef TIMInput_Config;
/* Configure the TIM peripheral *********************************************/
/* Set TIMx instance */
Input_Handle.Instance = TIM14;
/* TIM14 configuration: Input Capture mode ---------------------
The LSI oscillator is connected to TIM14 CH1.
The Rising edge is used as active edge.
The TIM14 CCR1 is used to compute the frequency value.
------------------------------------------------------------ */
Input_Handle.Init.Prescaler = 0;
Input_Handle.Init.CounterMode = TIM_COUNTERMODE_UP;
Input_Handle.Init.Period = 0xFFFF;
Input_Handle.Init.ClockDivision = 0;
Input_Handle.Init.RepetitionCounter = 0;
if(HAL_TIM_IC_Init(&Input_Handle) != HAL_OK)
{
/* Initialization Error */
Error_Handler();
}
/* Connect internally the TIM14_CH1 Input Capture to the LSI clock output */
Input_Handle.Instance->OR |= 0x3; // TIM14_OR linked to MCO
HAL_RCC_MCOConfig(RCC_MCO, RCC_MCO1SOURCE_LSI, RCC_MCODIV_1);
/* Configure the Input Capture of channel 1 */
TIMInput_Config.ICPolarity = TIM_ICPOLARITY_RISING;
TIMInput_Config.ICSelection = TIM_ICSELECTION_DIRECTTI;
TIMInput_Config.ICPrescaler = TIM_ICPSC_DIV8;
TIMInput_Config.ICFilter = 0;
if(HAL_TIM_IC_ConfigChannel(&Input_Handle, &TIMInput_Config, TIM_CHANNEL_1) != HAL_OK)
{
/* Initialization Error */
Error_Handler();
}
/* Reset the flags */
Input_Handle.Instance->SR = 0;
/* Start the TIM Input Capture measurement in interrupt mode */
if(HAL_TIM_IC_Start_IT(&Input_Handle, TIM_CHANNEL_1) != HAL_OK)
{
Error_Handler();
}
/* Wait until the TIM14 get 2 LSI edges (refer to TIM14_IRQHandler() in
stm32f3xx_it.c file) ******************************************************/
while(uwCaptureNumber != 2)
{
}
/* Disable TIM14 CC1 Interrupt Request */
HAL_TIM_IC_Stop_IT(&Input_Handle, TIM_CHANNEL_1);
/* Deinitialize the TIM14 peripheral registers to their default reset values */
HAL_TIM_IC_DeInit(&Input_Handle);
return uwLsiFreq/*0*/;
}
