diff --git a/main/main.c b/main/main.c
index 3a06fb1..714ff14 100644
--- a/main/main.c
+++ b/main/main.c
@@ -26,6 +26,7 @@ void app_main(void) {
   ambient_light_auto_fetch();
   auto_fetch_temperature();
   pca9555_init();
+  pca9555_auto_fetch();
   ui_input_init();
   xTaskCreate(mqtt_publish_ui_input, "mqtt_publish_ui_input", 2048, NULL, 10,
               NULL);
diff --git a/main/pca9555.c b/main/pca9555.c
index d08a3c2..a881f53 100644
--- a/main/pca9555.c
+++ b/main/pca9555.c
@@ -19,8 +19,86 @@
 #define PCA95555_CMD_CONFIGURATION_PORT_0 0x06
 #define PCA95555_CMD_CONFIGURATION_PORT_1 0x07
 
+esp_err_t pca9555_write_config(uint8_t cmd_byte, uint8_t data) {
+  i2c_cmd_handle_t cmd = i2c_cmd_link_create();
+  i2c_master_start(cmd);
+  i2c_master_write_byte(cmd, PCA9555_ADDRESS << 1 | I2C_MASTER_WRITE,
+                        ACK_CHECK_EN);
+  i2c_master_write_byte(cmd, cmd_byte, ACK_CHECK_EN);
+  i2c_master_write_byte(cmd, data, ACK_CHECK_EN);
+  i2c_master_stop(cmd);
+  esp_err_t error =
+      i2c_master_cmd_begin(I2C_MASTER_NUM, cmd, 1000 / portTICK_PERIOD_MS);
+  i2c_cmd_link_delete(cmd);
+  if (error != ESP_OK) {
+    ESP_LOGW(PCA_9555_TAG, "write config failed. %d", error);
+  }
+  return error;
+}
 
+esp_err_t pca9555_write_output(uint8_t cmd_byte, uint8_t data) {
+  i2c_cmd_handle_t cmd = i2c_cmd_link_create();
+  i2c_master_start(cmd);
+  i2c_master_write_byte(cmd, PCA9555_ADDRESS << 1 | I2C_MASTER_WRITE,
+                        ACK_CHECK_EN);
+  i2c_master_write_byte(cmd, cmd_byte, ACK_CHECK_EN);
+  i2c_master_write_byte(cmd, data, ACK_CHECK_EN);
+  i2c_master_stop(cmd);
+  esp_err_t error =
+      i2c_master_cmd_begin(I2C_MASTER_NUM, cmd, 1000 / portTICK_PERIOD_MS);
+  i2c_cmd_link_delete(cmd);
+  if (error != ESP_OK) {
+    ESP_LOGW(PCA_9555_TAG, "write output failed. %d", error);
+  }
+  return error;
+}
 
+esp_err_t pca9555_read_one_input(uint8_t cmd_byte, uint8_t* data) {
+  i2c_cmd_handle_t cmd = i2c_cmd_link_create();
+  i2c_master_start(cmd);
+  i2c_master_write_byte(cmd, PCA9555_ADDRESS << 1 | I2C_MASTER_WRITE,
+                        ACK_CHECK_EN);
+  i2c_master_write_byte(cmd, cmd_byte, ACK_CHECK_EN);
+  i2c_master_start(cmd);
+  i2c_master_write_byte(cmd, PCA9555_ADDRESS << 1 | I2C_MASTER_READ,
+                        ACK_CHECK_EN);
+  i2c_master_read_byte(cmd, data, NACK_VAL);
+  i2c_master_stop(cmd);
+  esp_err_t error =
+      i2c_master_cmd_begin(I2C_MASTER_NUM, cmd, 1000 / portTICK_PERIOD_MS);
+  i2c_cmd_link_delete(cmd);
+  if (error != ESP_OK) {
+    ESP_LOGW(PCA_9555_TAG, "read input failed. %d", error);
+  }
+  return error;
+}
+
+void pca9555_fetch(void* arg) {
+  ESP_LOGI(PCA_9555_TAG, "fetching");
+  esp_err_t error;
+  uint8_t buff;
+  char disp_str[17];
+  display_fill_rect(0, 6, 128, 8, 0x00);
+  for (;;) {
+    error = pca9555_read_one_input(PCA95555_CMD_INPUT_PORT_1, &buff);
+    if (error != ESP_OK) {
+      ESP_LOGW(PCA_9555_TAG, "read failed. %x", error);
+    } else {
+      sprintf(disp_str, "IO0: 0x%2x  ", buff);
+      display_print8_str(8, 6, disp_str);
+      ESP_LOGD(PCA_9555_TAG, "IO0: 0x%2x", buff);
+    }
+    vTaskDelay(pdMS_TO_TICKS(10));
+  }
+  display_fill_rect(0, 6, 128, 8, 0x00);
+}
+
+void pca9555_auto_fetch() {
+  if (is_apds_9930_online == 0) {
+    return;
+  }
+  xTaskCreate(pca9555_fetch, "pac05555-fetching", 2048, NULL, 10, NULL);
+}
 
 void pca9555_init() {
   if (is_pca9555_online == 0) {
@@ -28,5 +106,6 @@ void pca9555_init() {
     return;
   }
   ESP_LOGI(PCA_9555_TAG, "Initializing PCA9555");
-  // esp_log_level_set(PCA_9555_TAG, ESP_LOG_ERROR);
+  esp_log_level_set(PCA_9555_TAG, ESP_LOG_DEBUG);
+  pca9555_write_config(PCA95555_CMD_CONFIGURATION_PORT_1, 0x01);
 }