diff -r 000000000000 -r 88d965579617 main/u8g2_esp32_hal.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main/u8g2_esp32_hal.h	Tue Oct 08 12:00:31 2019 +0200
@@ -0,0 +1,41 @@
+/*
+ * u8g2_esp32_hal.h
+ *
+ *  Created on: Feb 12, 2017
+ *      Author: kolban
+ */
+
+#ifndef U8G2_ESP32_HAL_H_
+#define U8G2_ESP32_HAL_H_
+#include "u8g2.h"
+
+#include "driver/gpio.h"
+#include "driver/spi_master.h"
+#include "driver/i2c.h"
+
+#define U8G2_ESP32_HAL_UNDEFINED (-1)
+
+#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 ACK_CHECK_EN   0x1                 //  I2C master will check ack from slave
+#define ACK_CHECK_DIS  0x0                 //  I2C master will not check ack from slave
+
+typedef struct {
+	gpio_num_t clk;
+	gpio_num_t mosi;
+	gpio_num_t sda; // data for I²C
+	gpio_num_t scl; // clock for I²C
+	gpio_num_t cs;
+	gpio_num_t reset;
+	gpio_num_t dc;
+} u8g2_esp32_hal_t ;
+
+#define U8G2_ESP32_HAL_DEFAULT {U8G2_ESP32_HAL_UNDEFINED, U8G2_ESP32_HAL_UNDEFINED, U8G2_ESP32_HAL_UNDEFINED, U8G2_ESP32_HAL_UNDEFINED, U8G2_ESP32_HAL_UNDEFINED, U8G2_ESP32_HAL_UNDEFINED, U8G2_ESP32_HAL_UNDEFINED }
+
+void u8g2_esp32_hal_init(u8g2_esp32_hal_t u8g2_esp32_hal_param);
+uint8_t u8g2_esp32_spi_byte_cb(u8x8_t *u8x8, uint8_t msg, uint8_t arg_int, void *arg_ptr);
+uint8_t u8g2_esp32_i2c_byte_cb(u8x8_t *u8x8, uint8_t msg, uint8_t arg_int, void *arg_ptr);
+uint8_t u8g2_esp32_gpio_and_delay_cb(u8x8_t *u8x8, uint8_t msg, uint8_t arg_int, void *arg_ptr);
+#endif /* U8G2_ESP32_HAL_H_ */