freeRTOS USING INTERRUPT AND TIMER ONESHOT IN A CODE MORSE PROJECT W ESP32 - embedded

Question

Eve guys,see, I took a shot developing this code. It's about a morse code encoder. I started from the beggining. This part that Ill show yall, I just copyied a documentation I took somewhere on internet.
I had a doubt and an request. I ask if u guy could (if it existed) an alternative way (more exploring hardware) for eencoding the morse code. And here goes the doubt, why the interrupt negative sensibility works better here? I found it very awkard when i changed it for POSEDGE, and realized that the proposal didnt work at all. ( the dashs rarely were captured).
Thats all. I Appreciate the help beforehand
#define BLINK_GPIO 21 //2
#define BUTTON_GPIO 0
#define ESP_INTR_FLAG_DEFAULT 0
#define DASH_PRD pdMS_TO_TICKS(200)
#define INTC_PRD pdMS_TO_TICKS(1000)
char morse[6];
uint8_t cnt = 0;
TimerHandle_t xOneShotTimerDASH;// handle para o SoftTimer
BaseType_t xDASHTimerStarted, xINTCTimerStarted; // flag para checar timer
static void timerDASH_callback(void *pvParameters);
//static void timerINTC_callback(void *pvParameters);
static void IRAM_ATTR gpio_isr_handler(void* arg)
{
xDASHTimerStarted = xTimerStart(xOneShotTimerDASH, 0);
// xINTCTimerStarted = xTimerStart(xOneShotTimerINTC, 0);
}
void app_main(void)
{
gpio_pad_select_gpio(BLINK_GPIO); // Configura o pino como IO
gpio_set_direction(BLINK_GPIO,GPIO_MODE_OUTPUT); // Configura o IO como saida
gpio_pad_select_gpio(BUTTON_GPIO); // Configura o pino como IO
gpio_set_direction(BUTTON_GPIO,GPIO_MODE_INPUT); // Configura o IO como entrada
gpio_set_intr_type(BUTTON_GPIO,GPIO_INTR_POSEDGE);
gpio_intr_enable(BUTTON_GPIO);
gpio_install_isr_service(ESP_INTR_FLAG_DEFAULT);
gpio_isr_handler_add(BUTTON_GPIO, gpio_isr_handler, (void*) BUTTON_GPIO);
ESP_LOGI("STARTUP","ISR Handler Instalado!!!");
/* Create the one shot timer, storing the handle to the created timer in xOneShotTimer. */
xOneShotTimerDASH = xTimerCreate("OneShot", DASH_PRD, pdFALSE, 0, timerDASH_callback);
ESP_LOGI("STARTUP","DASH Timer Criado!!!");
/* Create the one shot timer, storing the handle to the created timer in xOneShotTimer. */
//xOneShotTimerINTC = xTimerCreate("OneShot", INTC_PRD, pdFALSE, 0, timerINTC_callback);
ESP_LOGI("STARTUP","DASH Timer Criado!!!");
}
static void timerDASH_callback(void *pvParameters)
{
if(gpio_get_level(BUTTON_GPIO))
{
ESP_LOGI("MORSE",".");
morse[cnt++] = '.';
}
else
{
ESP_LOGI("MORSE","_");
morse[cnt++] = '_';
}
}