esp32-s2/main/main.c

/* SPDX-License-Identifier: GPL-3.0-or-later
 * Copyright 2022-2023 King Kévin <kingkevin@cuvoodoo.info>
 */
#include <stdio.h>
#include <stdlib.h>
#include <sys/reent.h>
#include "esp_log.h"
#include "esp_mac.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "tinyusb.h"
#include "tusb_cdc_acm.h"
#include "tusb_dfu_rt.h"
#include "tusb_console.h"
#include "sdkconfig.h"

#include "driver/gpio.h"

// GPIO to force DFU mode (on high)
#define DFU_PIN 14
// GPIO for on-board LED (WEMOS S2 mini, source on)
#define LED_BOARD 15

static const char *TAG = "main";

/**
 * @brief USB string descriptor
 */
static const char* usb_str_desc[USB_STRING_DESCRIPTOR_ARRAY_SIZE] = {
	(char[]){0x09, 0x04},                    // 0: language: English
	CONFIG_TINYUSB_DESC_MANUFACTURER_STRING, // 1: Manufacturer
	CONFIG_TINYUSB_DESC_PRODUCT_STRING,      // 2: Product
	CONFIG_TINYUSB_DESC_SERIAL_STRING,       // 3: Serials, should use chip ID
	CONFIG_TINYUSB_DESC_CDC_STRING,          // 4: CDC Interface
	"",                                      // 5: MSC Interface
	"DFU (runtime mode)"                     // 6: DFU RT
};

void app_main(void)
{
	// check DFU force
	gpio_config_t io_conf = {}; // to configure GPIO
	// GPIO0 can also be pressed while soft reboot
	io_conf.pin_bit_mask = (1ULL << 0); // GPIO to configure
	io_conf.intr_type = GPIO_INTR_DISABLE; // disable interrupt
	io_conf.mode = GPIO_MODE_INPUT; // set as input
	io_conf.pull_down_en = false; // disable pull-down mode
	io_conf.pull_up_en = true; // enable pull-up mode
	ESP_ERROR_CHECK( gpio_config(&io_conf) ); // configure GPIO
	// dedicated DFU button
	io_conf.pin_bit_mask = (1ULL << DFU_PIN); // GPIO to configure
	io_conf.intr_type = GPIO_INTR_DISABLE; // disable interrupt
	io_conf.mode = GPIO_MODE_INPUT; // set as input
	io_conf.pull_down_en = 1; // enable pull-down mode
	io_conf.pull_up_en = 0; // disable pull-up mode
	ESP_ERROR_CHECK( gpio_config(&io_conf) ); // configure GPIO
	if (!gpio_get_level(0) || gpio_get_level(DFU_PIN)) { // DFU mode asserted
		tud_dfu_runtime_reboot_to_dfu_cb(); // reboot to DFU mode
	}

	// configure LEDs
	io_conf.pin_bit_mask = (1ULL << LED_BOARD); // GPIO to configure
	io_conf.intr_type = GPIO_INTR_DISABLE; // disable interrupt
	io_conf.mode = GPIO_MODE_INPUT_OUTPUT; // set as output (push-pull), and input to read state
	io_conf.pull_down_en = 0; // disable pull-down mode
	io_conf.pull_up_en = 0; // disable pull-up mode
	ESP_ERROR_CHECK( gpio_config(&io_conf) ); // configure GPIO
	gpio_set_level(LED_BOARD, 0); // switch running LED off until all is ready

	// setup USB CDC ACM for printing
	ESP_LOGI(TAG, "USB initialization");
	// get MAC
	uint8_t mac[6];
	esp_read_mac(mac, ESP_MAC_ETH);
	static char usb_serial[13] = {0};
	snprintf(usb_serial, sizeof(usb_serial), "%02X%02X%02X%02X%02X%02X", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
	usb_str_desc[3] = usb_serial;
	const tinyusb_config_t tusb_cfg = {
		.device_descriptor = NULL, // use default USB descriptor
		.string_descriptor = usb_str_desc, // use custom string description to set serial
		.external_phy = false, // use integrated phy
		.configuration_descriptor = NULL,
	};
	ESP_ERROR_CHECK( tinyusb_driver_install(&tusb_cfg) ); // configure USB
	tinyusb_config_cdcacm_t amc_cfg = { 0 }; // the configuration uses default values
	ESP_ERROR_CHECK( tusb_cdc_acm_init(&amc_cfg) ); // configure CDC ACM
	ESP_ERROR_CHECK( tusb_dfu_rf_init() ); // configure DFU runtime (ensures we can use it)
	esp_tusb_init_console(TINYUSB_CDC_ACM_0); // log to USB
	ESP_LOGI(TAG, "USB initialized");

	ESP_LOGI(TAG, "application ready");
	gpio_set_level(LED_BOARD, 0); // switch running LED on to indicate all is ready
	while (1) {
		vTaskDelay(1000 / portTICK_PERIOD_MS);
		// toggle LED as heart beat
		if (gpio_get_level(LED_BOARD)) {
			gpio_set_level(LED_BOARD, 0);
		} else {
			gpio_set_level(LED_BOARD, 1);
		}
	}
}