Add grid and EVSE meter components with load balancer

components/evsemeter/src/evsemeter_ade7758.c

@@ -0,0 +1,21 @@
+#include "evsemeter.h"
+#include "esp_event.h"
+#include "esp_log.h"
+
+static const char *TAG = "evsemeter_ade7758";
+
+esp_err_t evsemeter_init(void)
+{
+    ESP_LOGI(TAG, "Initializing EVSE meter (ADE7758)");
+    return ESP_OK;
+}
+
+esp_err_t evsemeter_read_current(float *current)
+{
+    if (!current) {
+        return ESP_ERR_INVALID_ARG;
+    }
+    *current = 0.0f;
+    esp_event_post(EVSEMETER_EVENT, EVSEMETER_EVENT_UPDATE, current, sizeof(float), portMAX_DELAY);
+    return ESP_OK;
+}