feat: Initial esp32-hacking project with firmware sources and docs

esp-crab/master_recv/main/app/app_gpio.c

@@ -0,0 +1,35 @@
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include "driver/gpio.h"
+#include "esp_log.h"
+#include "esp_timer.h"
+#include "esp_log.h"
+#include <sys/types.h>
+
+#define GPIO_INPUT_IO        27
+#define GPIO_INPUT_PIN_SEL  (1ULL << GPIO_INPUT_IO)
+extern int64_t time_zero;
+static const char *TAG = "GPIO";
+extern QueueHandle_t csi_recv_queue;
+
+static void IRAM_ATTR gpio_isr_handler(void *arg) 
+{
+    xQueueReset(csi_recv_queue);
+    time_zero = esp_timer_get_time();
+    uint32_t gpio_num = (uint32_t)arg;
+}
+
+void init_gpio() 
+{
+    gpio_config_t io_conf = {
+        .intr_type = GPIO_INTR_NEGEDGE,
+        .mode = GPIO_MODE_INPUT,
+        .pin_bit_mask = GPIO_INPUT_PIN_SEL,
+        .pull_up_en = GPIO_PULLUP_ENABLE,
+        .pull_down_en = GPIO_PULLDOWN_DISABLE,
+    };
+    gpio_config(&io_conf);
+    gpio_install_isr_service(0);
+    gpio_isr_handler_add(GPIO_INPUT_IO, gpio_isr_handler, (void *)GPIO_INPUT_IO);
+    ESP_LOGI(TAG, "GPIO %d configured with negative edge interrupt.", GPIO_INPUT_IO);
+}