diff --git a/code/hello_world_01/main/spi.c b/code/hello_world_01/main/spi.c
index 33a5a1f..dcaa76d 100644
--- a/code/hello_world_01/main/spi.c
+++ b/code/hello_world_01/main/spi.c
@@ -69,6 +69,16 @@ void spi_init()
  */
 esp_err_t epd_spi_send_sync_fullduplex(const uint8_t *tx_data, uint8_t *rx_data, size_t len)
 {
+    esp_err_t ret;
+    // ret = spi_device_set_speed(spi2, speed * 1000 * 1000);
+    // if (ret == ESP_OK) {
+    //     ESP_LOGI(TAG, "EPD speed changed to 4MHz");
+    // }else
+    // {
+    //     ESP_LOGE(TAG, "EPD speed changed ERROR");
+    //     return ESP_ERR_INVALID_ARG;
+    // }
+
     // 入参校验：长度为0 或 收发缓冲区同时为NULL
     if (len == 0 || (tx_data == NULL && rx_data == NULL)) {
         ESP_LOGE(TAG, "Invalid args: len=%d, tx=%p, rx=%p", len, tx_data, rx_data);
@@ -85,7 +95,7 @@ esp_err_t epd_spi_send_sync_fullduplex(const uint8_t *tx_data, uint8_t *rx_data,
     };
 
     // 2. 同步传输（无队列，阻塞等待硬件完成）
-    esp_err_t ret = spi_device_transmit(spi2, &t);
+    ret = spi_device_transmit(spi2, &t);
 
     if (ret != ESP_OK) {
         ESP_LOGE(TAG, "SPI full duplex transmit failed: %s", esp_err_to_name(ret));