Sudeep Mohanty
ba2daf3c9e
This commit adds a driver for reading the touch sensor from the ULP RISC-V core during sleep. The commit also adds an example to demonstrate this feature. Closes https://github.com/espressif/esp-idf/issues/10480
77 lines
1.9 KiB
C
77 lines
1.9 KiB
C
/*
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* SPDX-FileCopyrightText: 2023 Espressif Systems (Shanghai) CO LTD
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*
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* SPDX-License-Identifier: Unlicense OR CC0-1.0
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*/
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/*
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* ULP-RISC-V touch sensor example
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* This code runs on ULP-RISC-V coprocessor
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*/
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#include <stdint.h>
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#include "ulp_riscv.h"
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#include "ulp_riscv_utils.h"
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#include "ulp_riscv_touch_ulp_core.h"
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/* This variable will be exported as a public symbol, visible from main CPU: */
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uint32_t touch_data = 0;
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/* Touch pad threshold */
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#define TOUCH_PAD_THRESHOLD 1000U
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#define TOUCH_BUTTON_NUM 14U
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static const touch_pad_t button[TOUCH_BUTTON_NUM] = {
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TOUCH_PAD_NUM1,
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TOUCH_PAD_NUM2,
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TOUCH_PAD_NUM3,
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TOUCH_PAD_NUM4,
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TOUCH_PAD_NUM5,
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TOUCH_PAD_NUM6,
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TOUCH_PAD_NUM7,
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TOUCH_PAD_NUM8,
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TOUCH_PAD_NUM9,
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TOUCH_PAD_NUM10,
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TOUCH_PAD_NUM11,
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TOUCH_PAD_NUM12,
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TOUCH_PAD_NUM13,
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TOUCH_PAD_NUM14
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};
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int main (void)
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{
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esp_err_t err = ESP_OK;
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uint32_t benchmark = 0;
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uint32_t smooth = 0;
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uint32_t touch_value = 0;
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for (int i = 0; i < TOUCH_BUTTON_NUM; i++) {
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/* Read the benchmark and the filtered (smooth) touch data */
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err = ulp_riscv_touch_pad_read_benchmark(button[i], &benchmark);
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err = ulp_riscv_touch_pad_filter_read_smooth(button[i], &smooth);
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if (err != ESP_OK) {
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/* Skip channel this time */
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continue;
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}
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/* The difference between the benchmark and the smooth touch data
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* is used to determine an active touch pad.
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* Check if the touch value breaches the wakeup threshold.
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*/
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if (smooth > benchmark) {
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if ((smooth - benchmark) > TOUCH_PAD_THRESHOLD) {
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touch_value |= (1 << button[i]);
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}
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}
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}
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if (touch_value) {
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touch_data = touch_value;
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ulp_riscv_wakeup_main_processor();
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touch_value = 0;
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}
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/* ulp_riscv_halt() is called automatically when main exits */
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return 0;
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}
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