Workshop: ESP-IDF and ESP32-C6 - Assignment 7

#include <stdint.h>
#include <stdbool.h>
#include "ulp_lp_core.h"
#include "ulp_lp_core_utils.h"
#include "ulp_lp_core_gpio.h"
#include "ulp_lp_core_interrupts.h"

#define WAKEUP_PIN LP_IO_NUM_0
#define RED_PIN    LP_IO_NUM_4
#define GREEN_PIN  LP_IO_NUM_5

static uint32_t wakeup_count;
uint32_t start_toggle;

void LP_CORE_ISR_ATTR ulp_lp_core_lp_io_intr_handler(void)
{
    ulp_lp_core_gpio_clear_intr_status();
    wakeup_count++;
}

int main (void)
{
    /* Register interrupt for the wakeup pin */
    ulp_lp_core_intr_enable();
    ulp_lp_core_gpio_intr_enable(WAKEUP_PIN, LP_IO_INTR_POSEDGE);

    int level = 0;
    while (1) {
        /* Toggle the Red LED GPIO */
        ulp_lp_core_gpio_set_level(GREEN_PIN, 0);
        ulp_lp_core_gpio_set_level(RED_PIN, level);
        level = level ? 0 : 1;
        ulp_lp_core_delay_us(1000000);

        /* Wakeup the main processor after 4 toggles of the button */
        if (wakeup_count >= 4) {
            ulp_lp_core_gpio_set_level(RED_PIN, 0);
            ulp_lp_core_wakeup_main_processor();
            wakeup_count = 0;
        }
    }
    /* ulp_lp_core_halt() is called automatically when main exits */
    return 0;
}

# Set usual component variables
set(app_sources "hello_world_main.c")
idf_component_register(SRCS ${app_sources}
                       REQUIRES ulp
                       WHOLE_ARCHIVE)
#
# ULP support additions to component CMakeLists.txt.
#
# 1. The ULP app name must be unique (if multiple components use ULP).
set(ulp_app_name ulp_${COMPONENT_NAME})
#
# 2. Specify all C and Assembly source files.
#    Files should be placed into a separate directory (in this case, ulp/),
#    which should not be added to COMPONENT_SRCS.
set(ulp_sources "ulp/main.c")
#
# 3. List all the component source files which include automatically
#    generated ULP export file, ${ulp_app_name}.h:
set(ulp_exp_dep_srcs ${app_sources})
#
# 4. Call function to build ULP binary and embed in project using the argument
#    values above.
ulp_embed_binary(${ulp_app_name} "${ulp_sources}" "${ulp_exp_dep_srcs}")

#include <stdio.h>
#include "esp_sleep.h"
#include "driver/gpio.h"
#include "driver/rtc_io.h"
#include "ulp_lp_core.h"
#include "ulp_main.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"

extern const uint8_t ulp_main_bin_start[] asm("_binary_ulp_main_bin_start");
extern const uint8_t ulp_main_bin_end[]   asm("_binary_ulp_main_bin_end");

static void init_ulp_program(void);

#define WAKEUP_PIN  GPIO_NUM_0
#define RED_PIN     GPIO_NUM_4
#define GREEN_PIN   GPIO_NUM_5

void app_main(void)
{
    /* If user is using USB-serial-jtag then idf monitor needs some time to
    *  re-connect to the USB port. We wait 1 sec here to allow for it to make the reconnection
    *  before we print anything. Otherwise the chip will go back to sleep again before the user
    *  has time to monitor any output.
    */
    vTaskDelay(pdMS_TO_TICKS(1000));

    /* ULP caused wakeup */
    esp_sleep_wakeup_cause_t cause = esp_sleep_get_wakeup_cause();
    if (cause == ESP_SLEEP_WAKEUP_ULP) {
        printf("ULP woke up the main CPU! \n");
        ulp_lp_core_stop();
    }

    printf("In active mode\n");
    printf("Long press the wake button to put the chip to sleep and run the ULP\n");

    /* Initialize selected GPIOs */
    rtc_gpio_init(WAKEUP_PIN);
    rtc_gpio_set_direction(WAKEUP_PIN, RTC_GPIO_MODE_INPUT_ONLY);
    rtc_gpio_pulldown_dis(WAKEUP_PIN);
    rtc_gpio_pullup_dis(WAKEUP_PIN);

    rtc_gpio_init(RED_PIN);
    rtc_gpio_set_direction(RED_PIN, RTC_GPIO_MODE_OUTPUT_ONLY);
    rtc_gpio_pulldown_dis(RED_PIN);
    rtc_gpio_pullup_dis(RED_PIN);

    rtc_gpio_init(GREEN_PIN);
    rtc_gpio_set_direction(GREEN_PIN, RTC_GPIO_MODE_OUTPUT_ONLY);
    rtc_gpio_pulldown_dis(GREEN_PIN);
    rtc_gpio_pullup_dis(GREEN_PIN);

    int gpio_level = 0;
    int previous_gpio_level = 0;
    int cnt = 0;

    while (1) {
        /* Toggle the Green LED GPIO */
        rtc_gpio_set_level(RED_PIN, 0);
        rtc_gpio_set_level(GREEN_PIN, 1);
        vTaskDelay(pdMS_TO_TICKS(1000));
        rtc_gpio_set_level(GREEN_PIN, 0);
        vTaskDelay(pdMS_TO_TICKS(1000));

        /* Read the wakeup pin continuously */
        gpio_level = rtc_gpio_get_level(WAKEUP_PIN);
        if (gpio_level != previous_gpio_level) {
            previous_gpio_level = gpio_level;
            cnt++;
            if (cnt > 1) {
                rtc_gpio_set_level(GREEN_PIN, 0);
                cnt = 0;
                break;
                /* break and run the LP core code */
            }
        }
    }

    /* Load and run the ULP program */
    init_ulp_program();

    /* Go back to sleep, only the ULP will run */
    printf("Entering Deep-sleep mode\n\n");
    printf("Press the wake button at least 3 or 4 times to wake up the main CPU again\n");
    vTaskDelay(10);

    ESP_ERROR_CHECK( esp_sleep_enable_ulp_wakeup());

    esp_deep_sleep_start();
}

static void init_ulp_program(void)
{
    esp_err_t err = ulp_lp_core_load_binary(ulp_main_bin_start, (ulp_main_bin_end - ulp_main_bin_start));
    ESP_ERROR_CHECK(err);

    /* Start the program */
    ulp_lp_core_cfg_t cfg = {
        .wakeup_source = ULP_LP_CORE_WAKEUP_SOURCE_HP_CPU,
    };

    err = ulp_lp_core_run(&cfg);
    ESP_ERROR_CHECK(err);
}

# Enable ULP
CONFIG_ULP_COPROC_ENABLED=y
CONFIG_ULP_COPROC_TYPE_LP_CORE=y
CONFIG_ULP_COPROC_RESERVE_MEM=4096
# Set log level to Warning to produce clean output
CONFIG_BOOTLOADER_LOG_LEVEL_WARN=y
CONFIG_BOOTLOADER_LOG_LEVEL=2
CONFIG_LOG_DEFAULT_LEVEL_WARN=y
CONFIG_LOG_DEFAULT_LEVEL=2

In active mode
Long press the wake button to put the chip to sleep and run the ULP

Entering Deep-sleep mode
Press the wake button at least 3 or 4 times to wake up the main CPU again

ULP woke up the main CPU!
In active mode
Long press the wake button to put the chip to sleep and run the ULP