This is an automated email from the ASF dual-hosted git repository.
rymek pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/mynewt-core.git
commit fd0c300b2fccb6f6c2a58575f0193aa46fed1e0e
Author: Jerzy Kasenberg <jerzy.kasenb...@codecoup.pl>
AuthorDate: Fri May 12 11:32:28 2023 +0200
lvgl: Add support for ADC touch screen
This add support for resistive 4 wire touch screen,
where X+/X-/Y+/Y- electrodes are connected to GPIO
pins and MCU's ADC.
Signed-off-by: Jerzy Kasenberg <jerzy.kasenb...@codecoup.pl>
---
.../lvgl/indev/adc_touch/include/adc_touch.h | 56 +++++
hw/drivers/display/lvgl/indev/adc_touch/pkg.yml | 43 ++++
.../display/lvgl/indev/adc_touch/src/adc_touch.c | 227 +++++++++++++++++++++
hw/drivers/display/lvgl/indev/adc_touch/syscfg.yml | 83 ++++++++
hw/drivers/display/lvgl/pkg.yml | 2 +
hw/drivers/display/lvgl/syscfg.yml | 3 +
6 files changed, 414 insertions(+)
diff --git a/hw/drivers/display/lvgl/indev/adc_touch/include/adc_touch.h
b/hw/drivers/display/lvgl/indev/adc_touch/include/adc_touch.h
new file mode 100644
index 000000000..337770651
--- /dev/null
+++ b/hw/drivers/display/lvgl/indev/adc_touch/include/adc_touch.h
@@ -0,0 +1,56 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you 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.
+ */
+
+#ifndef ADC_TOUCH_H
+#define ADC_TOUCH_H
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef void * adc_dev_t;
+
+/**
+ * Open ADC device for touch screen access
+ *
+ * Function should be implemented by user to setup ADC that will be used
+ * to measure values connected to X and Y electrodes.
+ *
+ * @param x_pin - pin to use for X coordinate measurement.
+ * @param y_pin - pit to use for Y coordinate measurement.
+ * @return value to be used in subsequent adc_touch_adc_read function
+ */
+adc_dev_t adc_touch_adc_open(int x_pin, int y_pin);
+
+/**
+ * Read ADC value for given pin
+ *
+ * @param adc - value returned form adc_touch_adc_open()
+ * @param pin - one of the pins to measure
+ * @return value measured on selected pin
+ */
+uint16_t adc_touch_adc_read(adc_dev_t adc, int pin);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* ADC_TOUCH_H */
diff --git a/hw/drivers/display/lvgl/indev/adc_touch/pkg.yml
b/hw/drivers/display/lvgl/indev/adc_touch/pkg.yml
new file mode 100644
index 000000000..f7eca8c20
--- /dev/null
+++ b/hw/drivers/display/lvgl/indev/adc_touch/pkg.yml
@@ -0,0 +1,43 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements. See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership. The ASF licenses this file
+# to you 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.
+#
+
+pkg.name: hw/drivers/display/lvgl/indev/adc_touch
+pkg.description: ADC touch driver
+pkg.keywords:
+ - display
+ - touch
+
+
+pkg.cflags:
+ - -DLV_CONF_INCLUDE_SIMPLE
+
+pkg.req_apis:
+ - adc_touch_adc
+
+pkg.deps.(ADC_TOUCH_DEFAULT_ADC && NORDIC_NRFX):
+ - hw/drivers/display/lvgl/indev/adc_touch/adc_nrfx
+
+pkg.deps.(ADC_TOUCH_DEFAULT_ADC && MCU_STM32F4):
+ - hw/drivers/display/lvgl/indev/adc_touch/adc_stm32f4
+
+pkg.deps.(ADC_TOUCH_DEFAULT_ADC && MCU_STM32F7):
+ - hw/drivers/display/lvgl/indev/adc_touch/adc_stm32f7
+
+pkg.init:
+ adc_touch_init: 1100
diff --git a/hw/drivers/display/lvgl/indev/adc_touch/src/adc_touch.c
b/hw/drivers/display/lvgl/indev/adc_touch/src/adc_touch.c
new file mode 100644
index 000000000..453591b45
--- /dev/null
+++ b/hw/drivers/display/lvgl/indev/adc_touch/src/adc_touch.c
@@ -0,0 +1,227 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you 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.
+ */
+
+#include <stdio.h>
+#include <os/mynewt.h>
+#include <os/os_time.h>
+#include <os/os_dev.h>
+#include <hal/hal_gpio.h>
+#include <bsp/bsp.h>
+
+#include <hal/lv_hal_indev.h>
+#include <core/lv_disp.h>
+#include <lv_api_map.h>
+#include <adc_touch.h>
+
+static adc_dev_t touch_dev;
+
+struct touch_electrodes {
+ int xp_pin;
+ int yp_pin;
+ int xm_pin;
+ int ym_pin;
+};
+
+struct touch_electrodes electrodes = {
+ .xp_pin = MYNEWT_VAL(ADC_TOUCH_XP_PIN),
+ .yp_pin = MYNEWT_VAL(ADC_TOUCH_YP_PIN),
+ .xm_pin = MYNEWT_VAL(ADC_TOUCH_XM_PIN),
+ .ym_pin = MYNEWT_VAL(ADC_TOUCH_YM_PIN),
+};
+
+static lv_indev_drv_t adc_drv;
+static lv_indev_t *adc_dev;
+
+struct touch_screen_data {
+ /* ADC value for left edge */
+ uint16_t adc_left;
+ /* ADC value for right edge */
+ uint16_t adc_right;
+ /* ADC value for top edge */
+ uint16_t adc_top;
+ /* ADC value for bottom edge */
+ uint16_t adc_bottom;
+ /* Current value for X, Y detected */
+ int x;
+ int y;
+ /* Values that were last reported */
+ int last_x;
+ int last_y;
+};
+
+#define INVERTED_X (MYNEWT_VAL(ADC_TOUCH_ADC_LEFT) >
MYNEWT_VAL(ADC_TOUCH_ADC_RIGHT))
+#define INVERTED_Y (MYNEWT_VAL(ADC_TOUCH_ADC_TOP) >
MYNEWT_VAL(ADC_TOUCH_ADC_BOTTOM))
+
+static struct touch_screen_data touch_screen_data = {
+ .adc_left = MYNEWT_VAL(ADC_TOUCH_ADC_LEFT),
+ .adc_right = MYNEWT_VAL(ADC_TOUCH_ADC_RIGHT),
+ .adc_top = MYNEWT_VAL(ADC_TOUCH_ADC_TOP),
+ .adc_bottom = MYNEWT_VAL(ADC_TOUCH_ADC_BOTTOM),
+};
+
+void
+adc_touch_handler(void)
+{
+ bool touched;
+ int x;
+ int y;
+ int last_val;
+ int nx, ny;
+ touch_screen_data.x = -1;
+ touch_screen_data.y = -1;
+
+ /* Check if there is short between plates using GPIO
+ */
+ hal_gpio_init_in(electrodes.yp_pin, HAL_GPIO_PULL_UP);
+ hal_gpio_init_in(electrodes.ym_pin, HAL_GPIO_PULL_NONE);
+ hal_gpio_init_out(electrodes.xp_pin, 0);
+ hal_gpio_init_out(electrodes.xm_pin, 0);
+
+ os_cputime_delay_usecs(MYNEWT_VAL(ADC_TOUCH_ADC_DELAY_US));
+
+ touched = hal_gpio_read(electrodes.ym_pin) == 0;
+
+ if (touched) {
+ /* Short detected */
+
+ /* X+ = VCC
+ * X- = GND,
+ * Y+/Y- as input without pull-up
+ */
+ hal_gpio_init_out(electrodes.xp_pin, 1);
+ hal_gpio_init_in(electrodes.yp_pin, HAL_GPIO_PULL_NONE);
+ os_cputime_delay_usecs(MYNEWT_VAL(ADC_TOUCH_ADC_DELAY_US));
+
+ last_val = -1;
+ for (nx = 0; nx < 10; nx++) {
+ /* Take measurement on Y pin that is routed to ADC channel */
+ x = adc_touch_adc_read(touch_dev, electrodes.yp_pin);
+ if (abs((x - last_val)) > (x / 16)) {
+ last_val = x;
+ } else {
+ x = (x + last_val) / 2;
+ ++nx;
+ break;
+ }
+ }
+
+ /* Sanity check for ADC reading */
+ if (x < MYNEWT_VAL_ADC_TOUCH_ADC_X_MIN || x >
MYNEWT_VAL_ADC_TOUCH_ADC_X_MAX) {
+ goto done;
+ }
+
+ /* Y+ = VCC
+ * Y- = GND,
+ * X+/X- as input without pull-up
+ */
+ hal_gpio_init_out(electrodes.yp_pin, 1);
+ hal_gpio_init_out(electrodes.ym_pin, 0);
+ hal_gpio_init_in(electrodes.xp_pin, HAL_GPIO_PULL_NONE);
+ hal_gpio_init_in(electrodes.xm_pin, HAL_GPIO_PULL_NONE);
+
+ os_cputime_delay_usecs(MYNEWT_VAL(ADC_TOUCH_ADC_DELAY_US));
+
+ last_val = -1;
+ for (ny = 0; ny < 10; ++ny) {
+ /* Take measurement on X pin that is routed to ADC channel */
+ y = adc_touch_adc_read(touch_dev, electrodes.xp_pin);
+ if (abs((y - last_val)) > (y / 16)) {
+ last_val = y;
+ } else {
+ ++ny;
+ break;
+ }
+ }
+
+ /* Sanity check for ADC reading */
+ if (y < MYNEWT_VAL_ADC_TOUCH_ADC_Y_MIN || x >
MYNEWT_VAL_ADC_TOUCH_ADC_Y_MAX) {
+ goto done;
+ }
+
+ /* If x is outside what is considered left-right range, adjust range */
+ if (INVERTED_X) {
+ if (x > touch_screen_data.adc_left) {
+ touch_screen_data.adc_left = x;
+ } else if (x < touch_screen_data.adc_right) {
+ touch_screen_data.adc_right = x;
+ }
+ } else {
+ if (x < touch_screen_data.adc_left) {
+ touch_screen_data.adc_left = x;
+ } else if (x > touch_screen_data.adc_right) {
+ touch_screen_data.adc_right = x;
+ }
+ }
+ /* If y is outside what is considered top-bottom range, adjust range */
+ if (INVERTED_Y) {
+ if (y > touch_screen_data.adc_top) {
+ touch_screen_data.adc_top = y;
+ } else if (y < touch_screen_data.adc_bottom) {
+ touch_screen_data.adc_bottom = y;
+ }
+ } else {
+ if (y < touch_screen_data.adc_top) {
+ touch_screen_data.adc_top = y;
+ } else if (y > touch_screen_data.adc_bottom) {
+ touch_screen_data.adc_bottom = y;
+ }
+ }
+
+ /* Convert to display coordinates */
+ touch_screen_data.x = (x - touch_screen_data.adc_left) * LV_HOR_RES /
+ (touch_screen_data.adc_right -
touch_screen_data.adc_left);
+ touch_screen_data.y = (y - touch_screen_data.adc_top) * LV_VER_RES /
+ (touch_screen_data.adc_bottom -
touch_screen_data.adc_top);
+ }
+done:
+ hal_gpio_init_out(electrodes.xp_pin, 0);
+ hal_gpio_init_out(electrodes.xm_pin, 0);
+ hal_gpio_init_out(electrodes.yp_pin, 0);
+ hal_gpio_init_out(electrodes.ym_pin, 0);
+}
+
+static void
+adc_touch_read(lv_indev_drv_t *indev_drv, lv_indev_data_t *data)
+{
+ adc_touch_handler();
+
+ if (touch_screen_data.x < 0 || touch_screen_data.y < 0) {
+ data->point.x = touch_screen_data.last_x;
+ data->point.y = touch_screen_data.last_y;
+ data->state = LV_INDEV_STATE_REL;
+ } else {
+ touch_screen_data.last_x = touch_screen_data.x;
+ touch_screen_data.last_y = touch_screen_data.y;
+ data->point.x = touch_screen_data.last_x;
+ data->point.y = touch_screen_data.last_y;
+ data->state = LV_INDEV_STATE_PR;
+ }
+}
+
+void
+adc_touch_init(void)
+{
+ touch_dev = adc_touch_adc_open(electrodes.xp_pin, electrodes.yp_pin);
+
+ /* Register a keypad input device */
+ lv_indev_drv_init(&adc_drv);
+ adc_drv.type = LV_INDEV_TYPE_POINTER;
+ adc_drv.read_cb = adc_touch_read;
+ adc_dev = lv_indev_drv_register(&adc_drv);
+}
diff --git a/hw/drivers/display/lvgl/indev/adc_touch/syscfg.yml
b/hw/drivers/display/lvgl/indev/adc_touch/syscfg.yml
new file mode 100644
index 000000000..c6e7cc553
--- /dev/null
+++ b/hw/drivers/display/lvgl/indev/adc_touch/syscfg.yml
@@ -0,0 +1,83 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements. See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership. The ASF licenses this file
+# to you 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.
+#
+
+syscfg.defs:
+ ADC_TOUCH_XP_PIN:
+ description: >
+ Pin connected to touch screen X+ electrode.
+ value:
+ ADC_TOUCH_XM_PIN:
+ description: >
+ Pin connected to touch screen X- electrode.
+ value:
+ ADC_TOUCH_YP_PIN:
+ description: >
+ Pin connected to touch screen Y+ electrode.
+ value:
+ ADC_TOUCH_YM_PIN:
+ description: >
+ Pin connected to touch screen Y- electrode.
+ value:
+ ADC_TOUCH_ADC_X_MIN:
+ description: >
+ Minimum value of ADC for x reading.
+ Readings lower then this value will be considered invalid.
+ value: 4300
+ ADC_TOUCH_ADC_X_MAX:
+ description: >
+ Maximum value of ADC for x reading.
+ Readings higher then this value will be considered invalid.
+ value: 11500
+ ADC_TOUCH_ADC_Y_MIN:
+ description: >
+ Minimum value of ADC for y reading.
+ Readings lower then this value will be considered invalid.
+ value: 3400
+ ADC_TOUCH_ADC_Y_MAX:
+ description: >
+ Maximum value of ADC for y reading.
+ Readings higher then this value will be considered invalid.
+ value: 12500
+ ADC_TOUCH_ADC_LEFT:
+ description:
+ ADC value for X coordinate 0.
+ This value will be adjusted in runtime.
+ It can be set to value between ADC_TOUCH_ADC_X_MIN or
ADC_TOUCH_ADC_X_MAX.
+ value:
+ ADC_TOUCH_ADC_RIGHT:
+ description:
+ ADC value for X coordinate at the right edge of the screen.
+ This value will be adjusted in runtime.
+ It can be set to value between ADC_TOUCH_ADC_X_MIN or
ADC_TOUCH_ADC_X_MAX.
+ value:
+ ADC_TOUCH_ADC_TOP:
+ description:
+ ADC value for Y coordinate 0.
+ This value will be adjusted in runtime.
+ It can be set to value between ADC_TOUCH_ADC_Y_MIN or
ADC_TOUCH_ADC_Y_MAX.
+ value:
+ ADC_TOUCH_ADC_BOTTOM:
+ description:
+ ADC value for Y coordinate at the bottom edge of the screen.
+ This value will be adjusted in runtime.
+ It can be set to value between ADC_TOUCH_ADC_Y_MIN or
ADC_TOUCH_ADC_Y_MAX.
+ value:
+ ADC_TOUCH_ADC_DELAY_US:
+ description:
+ Delay after GPIO is set high and measurement
+ value: 30
diff --git a/hw/drivers/display/lvgl/pkg.yml b/hw/drivers/display/lvgl/pkg.yml
index faec417cb..b40e34aa6 100644
--- a/hw/drivers/display/lvgl/pkg.yml
+++ b/hw/drivers/display/lvgl/pkg.yml
@@ -73,6 +73,8 @@ pkg.deps.LVGL_XPT2046:
- "@apache-mynewt-core/hw/drivers/display/lvgl/indev/xpt2046"
pkg.deps.LVGL_STMPE610:
- "@apache-mynewt-core/hw/drivers/display/lvgl/indev/stmpe610"
+pkg.deps.LVGL_ADC_TOUCH:
+ - "@apache-mynewt-core/hw/drivers/display/lvgl/indev/adc_touch"
pkg.cflags:
- -DLV_CONF_INCLUDE_SIMPLE=1
diff --git a/hw/drivers/display/lvgl/syscfg.yml
b/hw/drivers/display/lvgl/syscfg.yml
index 504f2a1ac..7da15004b 100644
--- a/hw/drivers/display/lvgl/syscfg.yml
+++ b/hw/drivers/display/lvgl/syscfg.yml
@@ -43,6 +43,9 @@ syscfg.defs:
LVGL_STMPE610:
description: Enable STMPE610 touchscreen driver.
value:
+ LVGL_ADC_TOUCH:
+ description: Enable ADC touchscreen driver.
+ value:
LVGL_TIMER_PERIOD_MS:
description: LV timer interval for periodical refresh and touch read
value: 10
