117 lines
3.8 KiB
C
117 lines
3.8 KiB
C
/*
|
|
* This file is part of the MicroPython project, http://micropython.org/
|
|
*
|
|
* The MIT License (MIT)
|
|
*
|
|
* Copyright (c) 2016 Scott Shawcroft for Adafruit Industries
|
|
* Copyright (c) 2018 Nick Moore for Adafruit Industries
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
* of this software and associated documentation files (the "Software"), to deal
|
|
* in the Software without restriction, including without limitation the rights
|
|
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
* copies of the Software, and to permit persons to whom the Software is
|
|
* furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included in
|
|
* all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
|
* THE SOFTWARE.
|
|
*/
|
|
|
|
#include <string.h>
|
|
#include <stdio.h>
|
|
|
|
#include "py/nlr.h"
|
|
#include "py/mperrno.h"
|
|
#include "py/runtime.h"
|
|
#include "py/binary.h"
|
|
#include "py/mphal.h"
|
|
#include "shared-bindings/touchio/TouchIn.h"
|
|
#include "supervisor/shared/translate.h"
|
|
|
|
#include "nrf.h"
|
|
|
|
// This is a capacitive touch sensing routine using a single digital
|
|
// pin. The pin should be connected to the sensing pad, and to ground
|
|
// via a 1Mohm or thereabout drain resistor. When a reading is taken,
|
|
// the pin's capacitance is charged by setting it to a digital output
|
|
// 'high' for a few microseconds, and then it is changed to a high
|
|
// impedance input. We measure how long it takes to discharge through
|
|
// the resistor (around 50us), using a busy-waiting loop, and average
|
|
// over N_SAMPLES cycles to reduce the effects of noise.
|
|
|
|
#define N_SAMPLES 10
|
|
#define TIMEOUT_TICKS 10000
|
|
|
|
static uint16_t get_raw_reading(touchio_touchin_obj_t *self) {
|
|
|
|
uint16_t ticks = 0;
|
|
|
|
for (uint16_t i = 0; i < N_SAMPLES; i++) {
|
|
// set pad to digital output high for 10us to charge it
|
|
|
|
nrf_gpio_cfg_output(self->pin->number);
|
|
nrf_gpio_pin_set(self->pin->number);
|
|
mp_hal_delay_us(10);
|
|
|
|
// set pad back to an input and take some samples
|
|
|
|
nrf_gpio_cfg_input(self->pin->number, NRF_GPIO_PIN_NOPULL);
|
|
|
|
while(nrf_gpio_pin_read(self->pin->number)) {
|
|
if (ticks >= TIMEOUT_TICKS) return TIMEOUT_TICKS;
|
|
ticks++;
|
|
}
|
|
}
|
|
return ticks;
|
|
}
|
|
|
|
void common_hal_touchio_touchin_construct(touchio_touchin_obj_t* self,
|
|
const mcu_pin_obj_t *pin) {
|
|
self->pin = pin;
|
|
claim_pin(pin);
|
|
|
|
self->threshold = get_raw_reading(self) * 1.05 + 100;
|
|
}
|
|
|
|
bool common_hal_touchio_touchin_deinited(touchio_touchin_obj_t* self) {
|
|
return self->pin == NULL;
|
|
}
|
|
|
|
void common_hal_touchio_touchin_deinit(touchio_touchin_obj_t* self) {
|
|
if (common_hal_touchio_touchin_deinited(self)) {
|
|
return;
|
|
}
|
|
|
|
reset_pin_number(self->pin->number);
|
|
self->pin = NULL;
|
|
}
|
|
|
|
void touchin_reset() {
|
|
}
|
|
|
|
bool common_hal_touchio_touchin_get_value(touchio_touchin_obj_t *self) {
|
|
uint16_t reading = get_raw_reading(self);
|
|
return reading > self->threshold;
|
|
}
|
|
|
|
uint16_t common_hal_touchio_touchin_get_raw_value(touchio_touchin_obj_t *self) {
|
|
return get_raw_reading(self);
|
|
}
|
|
|
|
uint16_t common_hal_touchio_touchin_get_threshold(touchio_touchin_obj_t *self) {
|
|
return self->threshold;
|
|
}
|
|
|
|
void common_hal_touchio_touchin_set_threshold(touchio_touchin_obj_t *self,
|
|
uint16_t new_threshold) {
|
|
self->threshold = new_threshold;
|
|
}
|