Add touchio pullup rp2350

locale/circuitpython.pot

@@ -1555,6 +1555,10 @@ msgstr ""
 msgid "No pulldown on pin; 1Mohm recommended"
 msgstr ""
 
+#: ports/raspberrypi/common-hal/touchio/TouchIn.c
+msgid "No pullup on pin; 1Mohm recommended"
+msgstr ""
+
 #: py/moderrno.c
 msgid "No space left on device"
 msgstr ""
@@ -2577,7 +2581,8 @@ msgstr ""
 msgid "bits must be 32 or less"
 msgstr ""
 
-#: shared-bindings/audiodelays/Echo.c shared-bindings/audiodelays/PitchShift.c
+#: shared-bindings/audiodelays/Chorus.c shared-bindings/audiodelays/Echo.c
+#: shared-bindings/audiodelays/PitchShift.c
 #: shared-bindings/audiofilters/Distortion.c
 #: shared-bindings/audiofilters/Filter.c shared-bindings/audiomixer/Mixer.c
 msgid "bits_per_sample must be 8 or 16"

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

@@ -0,0 +1,103 @@
+// This file is part of the CircuitPython project: https://circuitpython.org
+//
+// SPDX-FileCopyrightText: Copyright (c) 2016 Scott Shawcroft for Adafruit Industries
+// SPDX-FileCopyrightText: Copyright (c) 2018 Nick Moore for Adafruit Industries
+//
+// SPDX-License-Identifier: MIT
+
+#include <string.h>
+#include <stdio.h>
+
+#include "py/runtime.h"
+#include "py/mphal.h"
+#include "shared-bindings/touchio/TouchIn.h"
+#include "shared-bindings/microcontroller/Pin.h"
+
+// Native touchio only for RP2350, which cannot do shared-module touchio
+#ifdef PICO_RP2350
+
+// 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 LOW for 10us to charge it
+
+        common_hal_digitalio_digitalinout_switch_to_output(self->digitalinout, false, DRIVE_MODE_PUSH_PULL);
+        mp_hal_delay_us(10);
+
+        // set pad back to an input and take some samples, waiting for it to go HIGH
+
+        common_hal_digitalio_digitalinout_switch_to_input(self->digitalinout, PULL_NONE);
+
+        while (!common_hal_digitalio_digitalinout_get_value(self->digitalinout)) {
+            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) {
+    common_hal_mcu_pin_claim(pin);
+    self->digitalinout = mp_obj_malloc(digitalio_digitalinout_obj_t, &digitalio_digitalinout_type);
+
+    common_hal_digitalio_digitalinout_construct(self->digitalinout, pin);
+
+    uint16_t raw_reading = get_raw_reading(self);
+    if (raw_reading == TIMEOUT_TICKS) {
+        common_hal_touchio_touchin_deinit(self);
+        mp_raise_ValueError(MP_ERROR_TEXT("No pullup on pin; 1Mohm recommended"));
+    }
+    self->threshold = raw_reading * 1.05 + 100;
+}
+
+bool common_hal_touchio_touchin_deinited(touchio_touchin_obj_t *self) {
+    return self->digitalinout == MP_OBJ_NULL;
+}
+
+void common_hal_touchio_touchin_deinit(touchio_touchin_obj_t *self) {
+    if (common_hal_touchio_touchin_deinited(self)) {
+        return;
+    }
+
+    common_hal_digitalio_digitalinout_deinit(self->digitalinout);
+    self->digitalinout = MP_OBJ_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;
+}
+
+#endif

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

@@ -0,0 +1,26 @@
+// This file is part of the CircuitPython project: https://circuitpython.org
+//
+// SPDX-FileCopyrightText: Copyright (c) 2016 Scott Shawcroft
+// SPDX-FileCopyrightText: Copyright (c) 2018 Nick Moore for Adafruit Industries
+//
+// SPDX-License-Identifier: MIT
+
+#pragma once
+
+#include "common-hal/microcontroller/Pin.h"
+#include "shared-bindings/digitalio/DigitalInOut.h"
+
+#include "py/obj.h"
+
+// Native touchio only for RP2350, which cannot do shared-module touchio
+#ifdef PICO_RP2350
+
+typedef struct {
+    mp_obj_base_t base;
+    digitalio_digitalinout_obj_t *digitalinout;
+    uint16_t threshold;
+} touchio_touchin_obj_t;
+
+void touchin_reset(void);
+
+#endif

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

@@ -0,0 +1,5 @@
+// This file is part of the CircuitPython project: https://circuitpython.org
+//
+// SPDX-FileCopyrightText: Copyright (c) 2024 Adafruit Industries LLC
+//
+// SPDX-License-Identifier: MIT

ports/raspberrypi/mpconfigport.mk

@@ -65,8 +65,10 @@ CIRCUITPY_ALARM = 0
 CIRCUITPY_PICODVI ?= 1
 
 # Our generic touchio uses a pull down and RP2350 A2 hardware doesn't work correctly.
-# So, turn touchio off because it doesn't work.
-CIRCUITPY_TOUCHIO = 0
+# So, turn generic touchio off because it doesn't work.
+# And use a "native" touchio that expects 1M pull-up resistor instead of pull-down
+CIRCUITPY_TOUCHIO = 1
+CIRCUITPY_TOUCHIO_USE_NATIVE ?= 1
 
 # delay in ms before calling cyw43_arch_init_with_country
 CIRCUITPY_CYW43_INIT_DELAY ?= 0