diff --git a/main/i2c_bitaxe.c b/main/i2c_bitaxe.c
index ca8a0ae..494c48b 100644
--- a/main/i2c_bitaxe.c
+++ b/main/i2c_bitaxe.c
@@ -5,8 +5,12 @@
 #define I2C_MASTER_SCL_IO 48        /*!< GPIO number used for I2C master clock */
 #define I2C_MASTER_SDA_IO 47        /*!< GPIO number used for I2C master data  */
 #define I2C_MASTER_FREQ_HZ 100000   /*!< I2C master clock frequency */
-#define I2C_MASTER_TX_BUF_DISABLE 0 /*!< I2C master doesn't need buffer */
-#define I2C_MASTER_RX_BUF_DISABLE 0 /*!< I2C master doesn't need buffer */
+
+#define I2C_MASTER_NUM 0            /*!< I2C master i2c port number, the number of i2c peripheral interfaces available will depend on the chip */
+#define I2C_MASTER_TIMEOUT_MS 1000
+
+//#define I2C_DEFAULT_TIMEOUT ( I2C_MASTER_TIMEOUT_MS / portTICK_PERIOD_MS )
+#define I2C_DEFAULT_TIMEOUT -1  //-1 means wait forever
 
 static i2c_master_bus_handle_t i2c_bus_handle;
 
@@ -55,7 +59,7 @@ esp_err_t i2c_bitaxe_register_read(i2c_master_dev_handle_t dev_handle, uint8_t r
     // return i2c_master_write_read_device(I2C_MASTER_NUM, device_address, &reg_addr, 1, data, len, I2C_MASTER_TIMEOUT_MS / portTICK_PERIOD_MS);
     //ESP_LOGI("I2C", "Reading %d bytes from register 0x%02X", len, reg_addr);
 
-    return i2c_master_transmit_receive(dev_handle, &reg_addr, 1, read_buf, len, I2C_MASTER_TIMEOUT_MS / portTICK_PERIOD_MS);
+    return i2c_master_transmit_receive(dev_handle, &reg_addr, 1, read_buf, len, I2C_DEFAULT_TIMEOUT);
 }
 
 /**
@@ -70,7 +74,7 @@ esp_err_t i2c_bitaxe_register_write_byte(i2c_master_dev_handle_t dev_handle, uin
 
     //return i2c_master_write_to_device(I2C_MASTER_NUM, device_address, write_buf, sizeof(write_buf), I2C_MASTER_TIMEOUT_MS / portTICK_PERIOD_MS);
 
-    return i2c_master_transmit(dev_handle, write_buf, 2, I2C_MASTER_TIMEOUT_MS / portTICK_PERIOD_MS);
+    return i2c_master_transmit(dev_handle, write_buf, 2, I2C_DEFAULT_TIMEOUT);
 }
 
 /**
@@ -81,7 +85,7 @@ esp_err_t i2c_bitaxe_register_write_byte(i2c_master_dev_handle_t dev_handle, uin
  */
 esp_err_t i2c_bitaxe_register_write_bytes(i2c_master_dev_handle_t dev_handle, uint8_t * data, uint8_t len)
 {
-    return i2c_master_transmit(dev_handle, data, len, I2C_MASTER_TIMEOUT_MS / portTICK_PERIOD_MS);
+    return i2c_master_transmit(dev_handle, data, len, I2C_DEFAULT_TIMEOUT);
 }
 
 /**
@@ -96,5 +100,5 @@ esp_err_t i2c_bitaxe_register_write_word(i2c_master_dev_handle_t dev_handle, uin
 
     //return i2c_master_write_to_device(I2C_MASTER_NUM, device_address, write_buf, sizeof(write_buf), I2C_MASTER_TIMEOUT_MS / portTICK_PERIOD_MS);
 
-    return i2c_master_transmit(dev_handle, write_buf, 3, I2C_MASTER_TIMEOUT_MS / portTICK_PERIOD_MS);
+    return i2c_master_transmit(dev_handle, write_buf, 3, I2C_DEFAULT_TIMEOUT);
 }
diff --git a/main/i2c_bitaxe.h b/main/i2c_bitaxe.h
index 399e010..67521bc 100644
--- a/main/i2c_bitaxe.h
+++ b/main/i2c_bitaxe.h
@@ -4,9 +4,6 @@
 #include "driver/i2c_master.h"
 //#include "driver/i2c.h"
 
-#define I2C_MASTER_NUM 0            /*!< I2C master i2c port number, the number of i2c peripheral interfaces available will depend on the chip */
-#define I2C_MASTER_TIMEOUT_MS 1000
-
 esp_err_t i2c_bitaxe_init(void);
 esp_err_t i2c_bitaxe_add_device(uint8_t device_address, i2c_master_dev_handle_t * dev_handle);