diff --git a/demo/oled/test.c b/demo/oled/test.c
index 31b9862..483d244 100644
--- a/demo/oled/test.c
+++ b/demo/oled/test.c
@@ -4,12 +4,12 @@
 #include "tool.h"
 #include "t_oled.h"
 
-void Cmd(uint8_t *data, size_t l) {
+uint8_t Cmd(uint8_t *data, size_t l) {
     Buf_Print("Cmd", data, l, 16);
 }
 
-void Data(uint8_t *data, size_t l) {
-    Buf_Print("Data", data, l, 16);
+uint8_t Data(uint8_t *data, size_t l) {
+    Buf_Print("Data", data, l, 128);
 }
 
 void Refresh_Call(OLED_T *dev) {
@@ -21,7 +21,7 @@ uint8_t oledbuf[8][128] = {0};
 
 void Test_OLED() {
     OLED_T oled = {
-            .height=(uint8_t) 64,
+            .height=64,
             .width=128,
             .state=IDLE,
             .buf=oledbuf,