esp-idf/components/driver/esp32/include/driver/touch_sensor.h
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C

// Copyright 2019 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#pragma once
#ifdef __cplusplus
extern "C" {
#endif
#include "driver/touch_sensor_common.h"
/**
* @brief Configure touch pad interrupt threshold.
*
* @note If FSM mode is set to TOUCH_FSM_MODE_TIMER, this function will be blocked for one measurement cycle and wait for data to be valid.
*
* @param touch_num touch pad index
* @param threshold interrupt threshold,
*
* @return
* - ESP_OK Success
* - ESP_ERR_INVALID_ARG if argument wrong
* - ESP_FAIL if touch pad not initialized
*/
esp_err_t touch_pad_config(touch_pad_t touch_num, uint16_t threshold);
/**
* @brief get touch sensor counter value.
* Each touch sensor has a counter to count the number of charge/discharge cycles.
* When the pad is not 'touched', we can get a number of the counter.
* When the pad is 'touched', the value in counter will get smaller because of the larger equivalent capacitance.
*
* @note This API requests hardware measurement once. If IIR filter mode is enabled,
* please use 'touch_pad_read_raw_data' interface instead.
*
* @param touch_num touch pad index
* @param touch_value pointer to accept touch sensor value
*
* @return
* - ESP_OK Success
* - ESP_ERR_INVALID_ARG Touch pad parameter error
* - ESP_ERR_INVALID_STATE This touch pad hardware connection is error, the value of "touch_value" is 0.
* - ESP_FAIL Touch pad not initialized
*/
esp_err_t touch_pad_read(touch_pad_t touch_num, uint16_t *touch_value);
/**
* @brief get filtered touch sensor counter value by IIR filter.
*
* @note touch_pad_filter_start has to be called before calling touch_pad_read_filtered.
* This function can be called from ISR
*
* @param touch_num touch pad index
* @param touch_value pointer to accept touch sensor value
*
* @return
* - ESP_OK Success
* - ESP_ERR_INVALID_ARG Touch pad parameter error
* - ESP_ERR_INVALID_STATE This touch pad hardware connection is error, the value of "touch_value" is 0.
* - ESP_FAIL Touch pad not initialized
*/
esp_err_t touch_pad_read_filtered(touch_pad_t touch_num, uint16_t *touch_value);
/**
* @brief get raw data (touch sensor counter value) from IIR filter process.
* Need not request hardware measurements.
*
* @note touch_pad_filter_start has to be called before calling touch_pad_read_raw_data.
* This function can be called from ISR
*
* @param touch_num touch pad index
* @param touch_value pointer to accept touch sensor value
*
* @return
* - ESP_OK Success
* - ESP_ERR_INVALID_ARG Touch pad parameter error
* - ESP_ERR_INVALID_STATE This touch pad hardware connection is error, the value of "touch_value" is 0.
* - ESP_FAIL Touch pad not initialized
*/
esp_err_t touch_pad_read_raw_data(touch_pad_t touch_num, uint16_t *touch_value);
/**
* @brief Callback function that is called after each IIR filter calculation.
* @note This callback is called in timer task in each filtering cycle.
* @note This callback should not be blocked.
* @param raw_value The latest raw data(touch sensor counter value) that
* points to all channels(raw_value[0..TOUCH_PAD_MAX-1]).
* @param filtered_value The latest IIR filtered data(calculated from raw data) that
* points to all channels(filtered_value[0..TOUCH_PAD_MAX-1]).
*
*/
typedef void (* filter_cb_t)(uint16_t *raw_value, uint16_t *filtered_value);
/**
* @brief Register the callback function that is called after each IIR filter calculation.
* @note The 'read_cb' callback is called in timer task in each filtering cycle.
* @param read_cb Pointer to filtered callback function.
* If the argument passed in is NULL, the callback will stop.
* @return
* - ESP_OK Success
* - ESP_ERR_INVALID_ARG set error
*/
esp_err_t touch_pad_set_filter_read_cb(filter_cb_t read_cb);
/**
* @brief Register touch-pad ISR.
* The handler will be attached to the same CPU core that this function is running on.
* @param fn Pointer to ISR handler
* @param arg Parameter for ISR
* @return
* - ESP_OK Success ;
* - ESP_ERR_INVALID_ARG GPIO error
* - ESP_ERR_NO_MEM No memory
*/
esp_err_t touch_pad_isr_register(intr_handler_t fn, void *arg);
/**
* @brief Set touch sensor measurement and sleep time.
* Excessive total time will slow down the touch response.
* Too small measurement time will not be sampled enough, resulting in inaccurate measurements.
*
* @note The greater the duty cycle of the measurement time, the more system power is consumed.
* @param sleep_cycle The touch sensor will sleep after each measurement.
* sleep_cycle decide the interval between each measurement.
* t_sleep = sleep_cycle / (RTC_SLOW_CLK frequency).
* The approximate frequency value of RTC_SLOW_CLK can be obtained using rtc_clk_slow_freq_get_hz function.
* @param meas_cycle The duration of the touch sensor measurement.
* t_meas = meas_cycle / 8M, the maximum measure time is 0xffff / 8M = 8.19 ms
* @return
* - ESP_OK on success
*/
esp_err_t touch_pad_set_meas_time(uint16_t sleep_cycle, uint16_t meas_cycle);
/**
* @brief Get touch sensor measurement and sleep time
* @param sleep_cycle Pointer to accept sleep cycle number
* @param meas_cycle Pointer to accept measurement cycle count.
* @return
* - ESP_OK on success
*/
esp_err_t touch_pad_get_meas_time(uint16_t *sleep_cycle, uint16_t *meas_cycle);
/**
* @brief Trigger a touch sensor measurement, only support in SW mode of FSM
* @return
* - ESP_OK on success
*/
esp_err_t touch_pad_sw_start(void);
/**
* @brief Set touch sensor interrupt threshold
* @param touch_num touch pad index
* @param threshold threshold of touchpad count, refer to touch_pad_set_trigger_mode to see how to set trigger mode.
* @return
* - ESP_OK on success
* - ESP_ERR_INVALID_ARG if argument is wrong
*/
esp_err_t touch_pad_set_thresh(touch_pad_t touch_num, uint16_t threshold);
/**
* @brief Get touch sensor interrupt threshold
* @param touch_num touch pad index
* @param threshold pointer to accept threshold
* @return
* - ESP_OK on success
* - ESP_ERR_INVALID_ARG if argument is wrong
*/
esp_err_t touch_pad_get_thresh(touch_pad_t touch_num, uint16_t *threshold);
/**
* @brief Set touch sensor interrupt trigger mode.
* Interrupt can be triggered either when counter result is less than
* threshold or when counter result is more than threshold.
* @param mode touch sensor interrupt trigger mode
* @return
* - ESP_OK on success
* - ESP_ERR_INVALID_ARG if argument is wrong
*/
esp_err_t touch_pad_set_trigger_mode(touch_trigger_mode_t mode);
/**
* @brief Get touch sensor interrupt trigger mode
* @param mode pointer to accept touch sensor interrupt trigger mode
* @return
* - ESP_OK on success
*/
esp_err_t touch_pad_get_trigger_mode(touch_trigger_mode_t *mode);
/**
* @brief Set touch sensor interrupt trigger source. There are two sets of touch signals.
* Set1 and set2 can be mapped to several touch signals. Either set will be triggered
* if at least one of its touch signal is 'touched'. The interrupt can be configured to be generated
* if set1 is triggered, or only if both sets are triggered.
* @param src touch sensor interrupt trigger source
* @return
* - ESP_OK on success
* - ESP_ERR_INVALID_ARG if argument is wrong
*/
esp_err_t touch_pad_set_trigger_source(touch_trigger_src_t src);
/**
* @brief Get touch sensor interrupt trigger source
* @param src pointer to accept touch sensor interrupt trigger source
* @return
* - ESP_OK on success
*/
esp_err_t touch_pad_get_trigger_source(touch_trigger_src_t *src);
/**
* @brief Set touch sensor group mask.
* Touch pad module has two sets of signals, 'Touched' signal is triggered only if
* at least one of touch pad in this group is "touched".
* This function will set the register bits according to the given bitmask.
* @param set1_mask bitmask of touch sensor signal group1, it's a 10-bit value
* @param set2_mask bitmask of touch sensor signal group2, it's a 10-bit value
* @param en_mask bitmask of touch sensor work enable, it's a 10-bit value
* @return
* - ESP_OK on success
* - ESP_ERR_INVALID_ARG if argument is wrong
*/
esp_err_t touch_pad_set_group_mask(uint16_t set1_mask, uint16_t set2_mask, uint16_t en_mask);
/**
* @brief Get touch sensor group mask.
* @param set1_mask pointer to accept bitmask of touch sensor signal group1, it's a 10-bit value
* @param set2_mask pointer to accept bitmask of touch sensor signal group2, it's a 10-bit value
* @param en_mask pointer to accept bitmask of touch sensor work enable, it's a 10-bit value
* @return
* - ESP_OK on success
*/
esp_err_t touch_pad_get_group_mask(uint16_t *set1_mask, uint16_t *set2_mask, uint16_t *en_mask);
/**
* @brief Clear touch sensor group mask.
* Touch pad module has two sets of signals, Interrupt is triggered only if
* at least one of touch pad in this group is "touched".
* This function will clear the register bits according to the given bitmask.
* @param set1_mask bitmask touch sensor signal group1, it's a 10-bit value
* @param set2_mask bitmask touch sensor signal group2, it's a 10-bit value
* @param en_mask bitmask of touch sensor work enable, it's a 10-bit value
* @return
* - ESP_OK on success
* - ESP_ERR_INVALID_ARG if argument is wrong
*/
esp_err_t touch_pad_clear_group_mask(uint16_t set1_mask, uint16_t set2_mask, uint16_t en_mask);
/**
* @brief To enable touch pad interrupt
* @return
* - ESP_OK on success
*/
esp_err_t touch_pad_intr_enable(void);
/**
* @brief To disable touch pad interrupt
* @return
* - ESP_OK on success
*/
esp_err_t touch_pad_intr_disable(void);
/**
* @brief To clear touch pad interrupt
* @return
* - ESP_OK on success
*/
esp_err_t touch_pad_intr_clear(void);
/**
* @brief set touch pad filter calibration period, in ms.
* Need to call touch_pad_filter_start before all touch filter APIs
* @param new_period_ms filter period, in ms
* @return
* - ESP_OK Success
* - ESP_ERR_INVALID_STATE driver state error
* - ESP_ERR_INVALID_ARG parameter error
*/
esp_err_t touch_pad_set_filter_period(uint32_t new_period_ms);
/**
* @brief get touch pad filter calibration period, in ms
* Need to call touch_pad_filter_start before all touch filter APIs
* @param p_period_ms pointer to accept period
* @return
* - ESP_OK Success
* - ESP_ERR_INVALID_STATE driver state error
* - ESP_ERR_INVALID_ARG parameter error
*/
esp_err_t touch_pad_get_filter_period(uint32_t *p_period_ms);
/**
* @brief start touch pad filter function
* This API will start a filter to process the noise in order to prevent false triggering
* when detecting slight change of capacitance.
* Need to call touch_pad_filter_start before all touch filter APIs
*
* @note This filter uses FreeRTOS timer, which is dispatched from a task with
* priority 1 by default on CPU 0. So if some application task with higher priority
* takes a lot of CPU0 time, then the quality of data obtained from this filter will be affected.
* You can adjust FreeRTOS timer task priority in menuconfig.
* @param filter_period_ms filter calibration period, in ms
* @return
* - ESP_OK Success
* - ESP_ERR_INVALID_ARG parameter error
* - ESP_ERR_NO_MEM No memory for driver
* - ESP_ERR_INVALID_STATE driver state error
*/
esp_err_t touch_pad_filter_start(uint32_t filter_period_ms);
/**
* @brief stop touch pad filter function
* Need to call touch_pad_filter_start before all touch filter APIs
* @return
* - ESP_OK Success
* - ESP_ERR_INVALID_STATE driver state error
*/
esp_err_t touch_pad_filter_stop(void);
/**
* @brief delete touch pad filter driver and release the memory
* Need to call touch_pad_filter_start before all touch filter APIs
* @return
* - ESP_OK Success
* - ESP_ERR_INVALID_STATE driver state error
*/
esp_err_t touch_pad_filter_delete(void);
#ifdef __cplusplus
}
#endif