KEY¶

Introduction¶

Note

In this section, we will talk about the onboard key on the DNESP32S3M development board.

Alientek DNESP32S3M development board has a key button (boot) for user input. Before reset, BOOT can be used to choose startup mode. After reset, BOOT can be used as normal key.

KEY

Overview¶

In the project, we created a new directory named KEY under the components directory to store the key driver code, including the key.h and key.c files.

Pin Configuration¶

According to the schematic, the onboard key is connected to GPIO0.

KEY_CIRCUIT

Code¶

KEY.h¶

/**
 * @file key.h
 * @author SHUAIWEN CUI (SHUAIWEN001@e.ntu.edu.sg)
 * @brief This file is for the onboard key.
 * @version 1.0
 * @date 2024-11-17
 * 
 * @copyright Copyright (c) 2024
 * 
 */

#ifndef __KEY_H__
#define __KEY_H__

#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "driver/gpio.h"

/* Pin Definition */
#define BOOT_GPIO_PIN   GPIO_NUM_0

/* IO Operation */
#define BOOT            gpio_get_level(BOOT_GPIO_PIN)

/* Key Press Definition */
#define BOOT_PRES       1       /* BOOT key pressed */

/* Function declarations */
/**
 * @brief       Initialize the key
 * @param       None
 * @retval      None
 */
void key_init(void);            /* Initialize the key */

/**
 * @brief       Key scan function
 * @param       mode: 0 / 1, with the following meanings:
 *              0: Non-continuous press (returns key value only on the first press.
 *                 Must release and press again to return a value).
 *              1: Continuous press supported (returns key value each time the function is called while the key is pressed).
 * @retval      Key value, defined as follows:
 *              BOOT_PRES, 1, BOOT key pressed
 */
uint8_t key_scan(uint8_t mode); /* Key scan function */

#endif

KEY.c¶

/**
 * @file key.c
 * @author SHUAIWEN CUI (SHUAIWEN001@e.ntu.edu.sg)
 * @brief This file is for the onboard key.
 * @version 1.0
 * @date 2024-11-17
 * 
 * @copyright Copyright (c) 2024
 * 
 */

#include "key.h"

/**
 * @brief       Initialize the key
 * @param       None
 * @retval      None
 */
void key_init(void)
{
    gpio_config_t gpio_init_struct;

    gpio_init_struct.intr_type = GPIO_INTR_DISABLE;         /* Disable pin interrupt */
    gpio_init_struct.mode = GPIO_MODE_INPUT;                /* Input mode */
    gpio_init_struct.pull_up_en = GPIO_PULLUP_ENABLE;       /* Enable pull-up */
    gpio_init_struct.pull_down_en = GPIO_PULLDOWN_DISABLE;  /* Disable pull-down */
    gpio_init_struct.pin_bit_mask = 1ull << BOOT_GPIO_PIN;  /* BOOT key pin */
    gpio_config(&gpio_init_struct);                         /* Configure and enable */
}

/**
 * @brief       Key scan function
 * @param       mode: 0 / 1, with the following meanings:
 *              0: Non-continuous press (returns key value only on the first press.
 *                 Must release and press again to return a value).
 *              1: Continuous press supported (returns key value each time the function is called while the key is pressed).
 * @retval      Key value, defined as follows:
 *              BOOT_PRES, 1, BOOT key pressed
 */
uint8_t key_scan(uint8_t mode)
{
    uint8_t keyval = 0;
    static uint8_t key_boot = 1;    /* Key release flag */

    if(mode)
    {
        key_boot = 1;
    }

    if (key_boot && (BOOT == 0))    /* Key release flag is 1 and any key is pressed */
    {
        vTaskDelay(10);             /* Debounce */
        key_boot = 0;

        if (BOOT == 0)
        {
            keyval = BOOT_PRES;
        }
    }
    else if (BOOT == 1)
    {
        key_boot = 1;
    }

    return keyval;                  /* Return key value */
}

Test Program¶

Replace the code in the main.c file with the following code:

/**
 * @file main.c
 * @author SHUAIWEN CUI (SHUAIWEN001@e.ntu.edu.sg)
 * @brief 
 * @version 1.0
 * @date 2024-11-17
 * 
 * @copyright Copyright (c) 2024
 * 
 */

/* Dependencies */
// Basic
#include "esp_system.h"
#include "esp_chip_info.h"
#include "esp_psram.h"
#include "esp_flash.h"
#include "nvs_flash.h"
#include "esp_log.h"

// RTOS
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"

// BSP
#include "led.h"
#include "key.h"

/**
 * @brief Entry point of the program
 * @param None
 * @retval None
 */
void app_main(void)
{
    esp_err_t ret;
    uint32_t flash_size;
    esp_chip_info_t chip_info;

    uint8_t key;

    // Initialize NVS
    ret = nvs_flash_init();
    if (ret == ESP_ERR_NVS_NO_FREE_PAGES || ret == ESP_ERR_NVS_NEW_VERSION_FOUND)
    {
        ESP_ERROR_CHECK(nvs_flash_erase()); // Erase if needed
        ret = nvs_flash_init();
    }

    // Get FLASH size
    esp_flash_get_size(NULL, &flash_size);
    esp_chip_info(&chip_info);

    // Display CPU core count
    printf("CPU Cores: %d\n", chip_info.cores);

    // Display FLASH size
    printf("Flash size: %ld MB flash\n", flash_size / (1024 * 1024));

    // Display PSRAM size
    printf("PSRAM size: %d bytes\n", esp_psram_get_size());

    // BSP
    led_init();
    key_init();

    while (1)
    {
        key = key_scan(0);

        switch(key)
        {
            case BOOT_PRES:
                led_toggle();
                break;
            default:
                break;
        }

        vTaskDelay(10);

    }

}