Merge pull request #1499 from nickzoic/nickzoic/circuitpython-nrf-touchin-1048

Nickzoic/circuitpython nrf touchin 1048

Author: tannewt

ports/nrf/Makefile

@@ -169,6 +169,8 @@ SRC_COMMON_HAL += \
 	supervisor/Runtime.c \
 	supervisor/__init__.c \
 	time/__init__.c \
+	touchio/__init__.c \
+	touchio/TouchIn.c \
 
 ifneq ($(SD), )
 SRC_COMMON_HAL += \

ports/nrf/common-hal/touchio/TouchIn.c

@@ -0,0 +1,116 @@
+/*
+ * 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;
+}

ports/nrf/common-hal/touchio/TouchIn.h

@@ -0,0 +1,43 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2016 Scott Shawcroft
+ * 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.
+ */
+
+#ifndef MICROPY_INCLUDED_NRF_COMMON_HAL_TOUCHIO_TOUCHIN_H
+#define MICROPY_INCLUDED_NRF_COMMON_HAL_TOUCHIO_TOUCHIN_H
+
+#include "common-hal/microcontroller/Pin.h"
+
+#include "py/obj.h"
+
+typedef struct {
+    mp_obj_base_t base;
+    const mcu_pin_obj_t *pin;
+    uint16_t threshold;
+} touchio_touchin_obj_t;
+
+void touchin_reset(void);
+
+#endif // MICROPY_INCLUDED_NRF_COMMON_HAL_TOUCHIO_TOUCHIN_H

ports/nrf/common-hal/touchio/__init__.c

@@ -0,0 +1 @@
+// No touchio module functions.

ports/nrf/mpconfigport.h

@@ -178,6 +178,8 @@ extern const struct _mp_obj_module_t neopixel_write_module;
 extern const struct _mp_obj_module_t usb_hid_module;
 extern const struct _mp_obj_module_t usb_midi_module;
 extern const struct _mp_obj_module_t bleio_module;
+extern const struct _mp_obj_module_t touchio_module;
+
 
 #if MICROPY_PY_BLEIO
 #define BLEIO_MODULE { MP_ROM_QSTR(MP_QSTR_bleio), MP_ROM_PTR(&bleio_module) },
@@ -209,6 +211,7 @@ extern const struct _mp_obj_module_t bleio_module;
     { MP_OBJ_NEW_QSTR (MP_QSTR_gamepad         ), (mp_obj_t)&gamepad_module         }, \
     { MP_OBJ_NEW_QSTR (MP_QSTR_time            ), (mp_obj_t)&time_module            }, \
     { MP_OBJ_NEW_QSTR (MP_QSTR_json            ), (mp_obj_t)&mp_module_ujson        }, \
+    { MP_OBJ_NEW_QSTR (MP_QSTR_touchio         ), (mp_obj_t)&touchio_module         }, \
     USBHID_MODULE  \
     { MP_OBJ_NEW_QSTR(MP_QSTR_usb_midi),(mp_obj_t)&usb_midi_module }, \
     BLEIO_MODULE