Posted on September 23, 2016 at 12:07Hi to all i have this problem, i have a STM32L152RE with a temperature Sensor,
this sensor use 1-wire protocol,the data is codifing with pulse width,
lather the mcu start the connection the sensor give the 40 bit,
i have 0 if the pulse width is 28 usec, i have 1 if the pulse is 70 usec.
I use cube_mx for configure the board, i use the time3, channel 2 with interrupt,
this is the my configuration
/* TIM3 init function */
static void MX_TIM3_Init(void)
{
TIM_ClockConfigTypeDef sClockSourceConfig;
TIM_MasterConfigTypeDef sMasterConfig;
TIM_IC_InitTypeDef sConfigIC;
htim3.Instance = TIM3;
htim3.Init.Prescaler = 32000; //1MHz
htim3.Init.CounterMode = TIM_COUNTERMODE_UP;
htim3.Init.Period = 65535;
htim3.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
if (HAL_TIM_Base_Init(&htim3) != HAL_OK)
{
Error_Handler();
}
sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
if (HAL_TIM_ConfigClockSource(&htim3, &sClockSourceConfig) != HAL_OK)
{
Error_Handler();
}
if (HAL_TIM_IC_Init(&htim3) != HAL_OK)
{
Error_Handler();
}
sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
if (HAL_TIMEx_MasterConfigSynchronization(&htim3, &sMasterConfig) != HAL_OK)
{
Error_Handler();
}
sConfigIC.ICPolarity = TIM_INPUTCHANNELPOLARITY_RISING;
sConfigIC.ICSelection = TIM_ICSELECTION_DIRECTTI;
sConfigIC.ICPrescaler = TIM_ICPSC_DIV1;
sConfigIC.ICFilter = 15; // input filter
if (HAL_TIM_IC_ConfigChannel(&htim3, &sConfigIC, TIM_CHANNEL_2) != HAL_OK)
{
Error_Handler();
}
now all work well, but where should I set the width codifing?:
void HAL_TIM_IC_CaptureCallback(TIM_HandleTypeDef *htim)
{
int i=0;
uint32_t input_capture;
if (htim->Instance==TIM3)
{
input_capture=__HAL_TIM_GetCompare(&htim3, TIM_CHANNEL_2); //READ TIM3 channel 2
printf ( '' Value: %u \n \r '' , input_capture); // debug
...
}
can you help me?
best regards
antonio
#one-wire #input_capture
