diff --git a/libraries/SD/src/utility/Sd2Card.cpp b/libraries/SD/src/utility/Sd2Card.cpp
index 1fc0f80..a1edc13 100644
--- a/libraries/SD/src/utility/Sd2Card.cpp
+++ b/libraries/SD/src/utility/Sd2Card.cpp
@@ -20,6 +20,9 @@
 #define USE_SPI_LIB
 #include <Arduino.h>
 #include "Sd2Card.h"
+#include "fpioa.h"
+#include "gpio.h"
+#include "wiring_digital.h"
 //------------------------------------------------------------------------------
 #ifndef SOFTWARE_SPI
 #ifdef USE_SPI_LIB
@@ -249,8 +252,18 @@ uint8_t Sd2Card::init(uint8_t sckRateID, uint8_t chipSelectPin) {
   uint32_t arg;
 
   // set pin modes
-  pinMode(chipSelectPin_, OUTPUT);
-  digitalWrite(chipSelectPin_, HIGH);
+//#ifdef BOARD_SIPEED_MAIXDUINO
+  int gpionum = get_gpio(chipSelectPin_);
+    if(gpionum >= 0){
+        fpioa_function_t function = fpioa_function_t(FUNC_GPIOHS0 + gpionum);
+        fpioa_set_function(chipSelectPin_, function);
+        gpiohs_set_drive_mode((uint8_t)gpionum, GPIO_DM_OUTPUT);
+         gpiohs_set_pin((uint8_t)gpionum, GPIO_PV_HIGH);
+    }
+//#else
+//  pinMode(chipSelectPin_, OUTPUT);
+//  digitalWrite(chipSelectPin_, HIGH);
+//#endif
 #ifndef USE_SPI_LIB
   pinMode(SPI_MISO_PIN, INPUT);
   pinMode(SPI_MOSI_PIN, OUTPUT);
diff --git a/libraries/Sipeed_OV2640/examples/selfie/selfie.ino b/libraries/Sipeed_OV2640/examples/selfie/selfie.ino
index f88d674..7a9b3f0 100644
--- a/libraries/Sipeed_OV2640/examples/selfie/selfie.ino
+++ b/libraries/Sipeed_OV2640/examples/selfie/selfie.ino
@@ -1,6 +1,5 @@
 #include <Sipeed_OV2640.h>
 #include <Sipeed_ST7789.h>
-#include <stdio.h>
 
 SPIClass spi_(SPI0); // MUST be SPI0 for Maix series on board LCD
 Sipeed_ST7789 lcd(320, 240, spi_);
@@ -10,11 +9,12 @@ Sipeed_OV2640 camera(FRAMESIZE_QVGA, PIXFORMAT_RGB565);
 
 void setup()
 {
+    Serial.begin(115200);
     lcd.begin(15000000, COLOR_RED);
     if(!camera.begin())
-      printf("camera init fail\n");
+      Serial.printf("camera init fail\n");
     else
-      printf("camera init success\n");
+      Serial.printf("camera init success\n");
     camera.run(true);
 }
 
@@ -22,7 +22,7 @@ void loop()
 {
   uint8_t*img = camera.snapshot();
   if(img == nullptr || img==0)
-    printf("snap fail\n");
+    Serial.printf("snap fail\n");
   else
     lcd.drawImage(0, 0, camera.width(), camera.height(), (uint16_t*)img);
 }