diff -r 495b7eafbf5a -r 090b9d36b7a1 main/u8g2_esp32_hal.h
--- a/main/u8g2_esp32_hal.h	Sun Nov 17 12:58:39 2019 +0100
+++ b/main/u8g2_esp32_hal.h	Thu Nov 21 22:19:27 2019 +0100
@@ -17,7 +17,7 @@
 #define I2C_MASTER_NUM I2C_NUM_1           ///<  I2C port number for master dev
 #define I2C_MASTER_TX_BUF_DISABLE   0      ///<  I2C master do not need buffer
 #define I2C_MASTER_RX_BUF_DISABLE   0      ///<  I2C master do not need buffer
-#define I2C_MASTER_FREQ_HZ          50000  ///<  I2C master clock frequency
+#define I2C_MASTER_FREQ_HZ          400000 ///<  I2C master clock frequency (original 50000)
 #define ACK_CHECK_EN   0x1                 ///<  I2C master will check ack from slave
 #define ACK_CHECK_DIS  0x0                 ///<  I2C master will not check ack from slave