diff --git a/examples/ad770x/main.c b/examples/ad770x/main.c
index 6b13afc..2a021cc 100644
--- a/examples/ad770x/main.c
+++ b/examples/ad770x/main.c
@@ -8,7 +8,6 @@
 #include <esp/uart.h>
 #include <espressif/esp_common.h>
 #include <stdio.h>
-#include <i2c/i2c.h>
 #include <ad770x/ad770x.h>
 #include <FreeRTOS.h>
 #include <task.h>
diff --git a/examples/ads1115_test/main.c b/examples/ads1115_test/main.c
index 8065f04..5c0c4db 100644
--- a/examples/ads1115_test/main.c
+++ b/examples/ads1115_test/main.c
@@ -17,6 +17,7 @@
 // Connect ADDR pin to GND
 #define ADDR ADS111X_ADDR_GND
 
+#define I2C_BUS 0
 #define SCL_PIN 5
 #define SDA_PIN 4
 
@@ -28,23 +29,27 @@ void user_init(void)
     uart_set_baud(0, 115200);
     printf("SDK version:%s\n", sdk_system_get_sdk_version());
 
-    i2c_init(SCL_PIN, SDA_PIN);
+    i2c_dev_t dev = {
+        .addr = ADDR,
+        .bus = I2C_BUS,
+    };
+    i2c_init(I2C_BUS, SCL_PIN, SDA_PIN, I2C_FREQ_100K);
 
-    ads111x_set_mode(ADDR, ADS111X_MODE_CONTUNOUS);
-    ads111x_set_data_rate(ADDR, ADS111X_DATA_RATE_32);
+    ads111x_set_mode(&dev, ADS111X_MODE_CONTUNOUS);
+    ads111x_set_data_rate(&dev, ADS111X_DATA_RATE_32);
 
-    ads111x_set_input_mux(ADDR, ADS111X_MUX_0_GND);
-    ads111x_set_gain(ADDR, GAIN);
+    ads111x_set_input_mux(&dev, ADS111X_MUX_0_GND);
+    ads111x_set_gain(&dev, GAIN);
 
     float gain_val = ads111x_gain_values[GAIN];
 
     while (true)
     {
         // wait for conversion end
-        while (ads111x_busy(ADDR)) {}
+        while (ads111x_busy(&dev)) {}
 
         // Read result
-        int16_t raw = ads111x_get_value(ADDR);
+        int16_t raw = ads111x_get_value(&dev);
 
         float voltage = gain_val / ADS111X_MAX_VALUE * raw;
 
diff --git a/examples/bh1750/bh1750_example.c b/examples/bh1750/bh1750_example.c
index fad67bd..b75115c 100644
--- a/examples/bh1750/bh1750_example.c
+++ b/examples/bh1750/bh1750_example.c
@@ -11,17 +11,20 @@
 
 #define SCL_PIN 5
 #define SDA_PIN 4
+#define I2C_BUS 0
 
 static void measure(void *pvParameters)
 {
-    bh1750_configure(BH1750_ADDR_LO,
-                     BH1750_CONTINUOUS_MODE | BH1750_HIGH_RES_MODE);
+    i2c_dev_t dev = {
+        .addr = BH1750_ADDR_LO,
+        .bus = I2C_BUS,
+    };
+    bh1750_configure(&dev, BH1750_CONTINUOUS_MODE | BH1750_HIGH_RES_MODE);
 
     while (1) {
         while(1) {
             vTaskDelay(200 / portTICK_PERIOD_MS);
-            
-            printf("Lux: %d\n", bh1750_read(BH1750_ADDR_LO));
+            printf("Lux: %d\n", bh1750_read(&dev));
         }
     }
 }
@@ -35,7 +38,7 @@ void user_init(void)
     printf("SDK version : %s\n", sdk_system_get_sdk_version());
     printf("GIT version : %s\n", GITSHORTREV);
 
-    i2c_init(SCL_PIN, SDA_PIN);
+    i2c_init(I2C_BUS, SCL_PIN, SDA_PIN, I2C_FREQ_100K);
 
     xTaskCreate(measure, "measure_task", 256, NULL, 2, NULL);
 }
diff --git a/examples/ds3231_test/ds3231_test.c b/examples/ds3231_test/ds3231_test.c
index 395cf83..b6f41bb 100644
--- a/examples/ds3231_test/ds3231_test.c
+++ b/examples/ds3231_test/ds3231_test.c
@@ -12,15 +12,21 @@
 
 #include "ds3231/ds3231.h"
 
+#define ADDR DS3231_ADDR
+#define I2C_BUS 0
+
 void task1(void *pvParameters)
 {
     struct tm time;
     float tempFloat;
-
+    i2c_dev_t dev = {
+        .addr = ADDR,
+        .bus = I2C_BUS,
+    };
     while(1) {
         vTaskDelay(100);
-        ds3231_getTime(&time);
-	ds3231_getTempFloat(&tempFloat);
+        ds3231_getTime(&dev, &time);
+	    ds3231_getTempFloat(&dev, &tempFloat);
         printf("TIME:%d:%d:%d, TEMPERATURE:%.2f DegC\r\n", time.tm_hour, time.tm_min, time.tm_sec, tempFloat);
     }
 }
@@ -36,7 +42,6 @@ void user_init(void)
     printf("GIT version : %s\n", GITSHORTREV);
 
     i2c_init(0,scl,sda,I2C_FREQ_400K);
-    ds3231_Init(0);
 
     xTaskCreate(task1, "tsk1", 256, NULL, 2, NULL);
 }
diff --git a/extras/ads111x/ads111x.c b/extras/ads111x/ads111x.c
index c9d3cf3..8e68ee4 100644
--- a/extras/ads111x/ads111x.c
+++ b/extras/ads111x/ads111x.c
@@ -6,7 +6,6 @@
  * BSD Licensed as described in the file LICENSE
  */
 #include "ads111x.h"
-#include <i2c/i2c.h>
 
 #define ADS111X_DEBUG
 
@@ -52,144 +51,144 @@ const float ads111x_gain_values[] = {
     [ADS111X_GAIN_0V256_3] = 0.256
 };
 
-static uint16_t read_reg(uint8_t addr, uint8_t reg)
+static uint16_t read_reg(i2c_dev_t* dev, uint8_t reg)
 {
     uint16_t res = 0;
-    if (i2c_slave_read(addr, &reg, (uint8_t *)&res, 2))
+    if (i2c_slave_read(dev->bus, dev->addr, &reg, (uint8_t *)&res, 2))
         debug("Could not read register %d", reg);
     //debug("Read %d: 0x%04x", reg, res);
     return res;
 }
 
-static void write_reg(uint8_t addr, uint8_t reg, uint16_t val)
+static void write_reg(i2c_dev_t* dev, uint8_t reg, uint16_t val)
 {
     //debug("Write %d: 0x%04x", reg, val);
     uint8_t buf[2] = { val >> 8, val};
-    if (i2c_slave_write(addr, &reg, buf, 2))
+    if (i2c_slave_write(dev->bus, dev->addr, &reg, buf, 2))
         debug("Could not write 0x%04x to register %d", val, reg);
 }
 
-static uint16_t read_conf_bits(uint8_t addr, uint8_t offs, uint16_t mask)
+static uint16_t read_conf_bits(i2c_dev_t* dev, uint8_t offs, uint16_t mask)
 {
-    return (read_reg(addr, REG_CONFIG) >> offs) & mask;
+    return (read_reg(dev, REG_CONFIG) >> offs) & mask;
 }
 
-static void write_conf_bits(uint8_t addr, uint16_t val, uint8_t offs, uint16_t mask)
+static void write_conf_bits(i2c_dev_t* dev, uint16_t val, uint8_t offs, uint16_t mask)
 {
-    write_reg(addr, REG_CONFIG, (read_reg(addr, REG_CONFIG) & ~(mask << offs)) | (val << offs));
+    write_reg(dev, REG_CONFIG, (read_reg(dev, REG_CONFIG) & ~(mask << offs)) | (val << offs));
 }
 
-bool ads111x_busy(uint8_t addr)
+bool ads111x_busy(i2c_dev_t* dev)
 {
-    return read_conf_bits(addr, OS_OFFSET, OS_MASK);
+    return read_conf_bits(dev, OS_OFFSET, OS_MASK);
 }
 
-void ads111x_start_conversion(uint8_t addr)
+void ads111x_start_conversion(i2c_dev_t* dev)
 {
-    write_conf_bits(addr, 1, OS_OFFSET, OS_MASK);
+    write_conf_bits(dev, 1, OS_OFFSET, OS_MASK);
 }
 
-int16_t ads111x_get_value(uint8_t addr)
+int16_t ads111x_get_value(i2c_dev_t* dev)
 {
-    return read_reg(addr, REG_CONVERSION);
+    return read_reg(dev, REG_CONVERSION);
 }
 
-ads111x_gain_t ads111x_get_gain(uint8_t addr)
+ads111x_gain_t ads111x_get_gain(i2c_dev_t* dev)
 {
-    return read_conf_bits(addr, PGA_OFFSET, PGA_MASK);
+    return read_conf_bits(dev, PGA_OFFSET, PGA_MASK);
 }
 
-void ads111x_set_gain(uint8_t addr, ads111x_gain_t gain)
+void ads111x_set_gain(i2c_dev_t* dev, ads111x_gain_t gain)
 {
-    write_conf_bits(addr, gain, PGA_OFFSET, PGA_MASK);
+    write_conf_bits(dev, gain, PGA_OFFSET, PGA_MASK);
 }
 
-ads111x_mux_t ads111x_get_input_mux(uint8_t addr)
+ads111x_mux_t ads111x_get_input_mux(i2c_dev_t* dev)
 {
-    return read_conf_bits(addr, MUX_OFFSET, MUX_MASK);
+    return read_conf_bits(dev, MUX_OFFSET, MUX_MASK);
 }
 
-void ads111x_set_input_mux(uint8_t addr, ads111x_mux_t mux)
+void ads111x_set_input_mux(i2c_dev_t* dev, ads111x_mux_t mux)
 {
-    write_conf_bits(addr, mux, MUX_OFFSET, MUX_MASK);
+    write_conf_bits(dev, mux, MUX_OFFSET, MUX_MASK);
 }
 
-ads111x_mode_t ads111x_get_mode(uint8_t addr)
+ads111x_mode_t ads111x_get_mode(i2c_dev_t* dev)
 {
-    return read_conf_bits(addr, MODE_OFFSET, MODE_MASK);
+    return read_conf_bits(dev, MODE_OFFSET, MODE_MASK);
 }
 
-void ads111x_set_mode(uint8_t addr, ads111x_mode_t mode)
+void ads111x_set_mode(i2c_dev_t* dev, ads111x_mode_t mode)
 {
-    write_conf_bits(addr, mode, MODE_OFFSET, MODE_MASK);
+    write_conf_bits(dev, mode, MODE_OFFSET, MODE_MASK);
 }
 
-ads111x_data_rate_t ads111x_get_data_rate(uint8_t addr)
+ads111x_data_rate_t ads111x_get_data_rate(i2c_dev_t* dev)
 {
-    return read_conf_bits(addr, DR_OFFSET, DR_MASK);
+    return read_conf_bits(dev, DR_OFFSET, DR_MASK);
 }
 
-void ads111x_set_data_rate(uint8_t addr, ads111x_data_rate_t rate)
+void ads111x_set_data_rate(i2c_dev_t* dev, ads111x_data_rate_t rate)
 {
-    write_conf_bits(addr, rate, DR_OFFSET, DR_MASK);
+    write_conf_bits(dev, rate, DR_OFFSET, DR_MASK);
 }
 
-ads111x_comp_mode_t ads111x_get_comp_mode(uint8_t addr)
+ads111x_comp_mode_t ads111x_get_comp_mode(i2c_dev_t* dev)
 {
-    return read_conf_bits(addr, COMP_MODE_OFFSET, COMP_MODE_MASK);
+    return read_conf_bits(dev, COMP_MODE_OFFSET, COMP_MODE_MASK);
 }
 
-void ads111x_set_comp_mode(uint8_t addr, ads111x_comp_mode_t mode)
+void ads111x_set_comp_mode(i2c_dev_t* dev, ads111x_comp_mode_t mode)
 {
-    write_conf_bits(addr, mode, COMP_MODE_OFFSET, COMP_MODE_MASK);
+    write_conf_bits(dev, mode, COMP_MODE_OFFSET, COMP_MODE_MASK);
 }
 
-ads111x_comp_polarity_t ads111x_get_comp_polarity(uint8_t addr)
+ads111x_comp_polarity_t ads111x_get_comp_polarity(i2c_dev_t* dev)
 {
-    return read_conf_bits(addr, COMP_POL_OFFSET, COMP_POL_MASK);
+    return read_conf_bits(dev, COMP_POL_OFFSET, COMP_POL_MASK);
 }
 
-void ads111x_set_comp_polarity(uint8_t addr, ads111x_comp_polarity_t polarity)
+void ads111x_set_comp_polarity(i2c_dev_t* dev, ads111x_comp_polarity_t polarity)
 {
-    write_conf_bits(addr, polarity, COMP_POL_OFFSET, COMP_POL_MASK);
+    write_conf_bits(dev, polarity, COMP_POL_OFFSET, COMP_POL_MASK);
 }
 
-ads111x_comp_latch_t ads111x_get_comp_latch(uint8_t addr)
+ads111x_comp_latch_t ads111x_get_comp_latch(i2c_dev_t* dev)
 {
-    return read_conf_bits(addr, COMP_LAT_OFFSET, COMP_LAT_MASK);
+    return read_conf_bits(dev, COMP_LAT_OFFSET, COMP_LAT_MASK);
 }
 
-void ads111x_set_comp_latch(uint8_t addr, ads111x_comp_latch_t latch)
+void ads111x_set_comp_latch(i2c_dev_t* dev, ads111x_comp_latch_t latch)
 {
-    write_conf_bits(addr, latch, COMP_LAT_OFFSET, COMP_LAT_MASK);
+    write_conf_bits(dev, latch, COMP_LAT_OFFSET, COMP_LAT_MASK);
 }
 
-ads111x_comp_queue_t ads111x_get_comp_queue(uint8_t addr)
+ads111x_comp_queue_t ads111x_get_comp_queue(i2c_dev_t* dev)
 {
-    return read_conf_bits(addr, COMP_QUE_OFFSET, COMP_QUE_MASK);
+    return read_conf_bits(dev, COMP_QUE_OFFSET, COMP_QUE_MASK);
 }
 
-void ads111x_set_comp_queue(uint8_t addr, ads111x_comp_queue_t queue)
+void ads111x_set_comp_queue(i2c_dev_t* dev, ads111x_comp_queue_t queue)
 {
-    write_conf_bits(addr, queue, COMP_QUE_OFFSET, COMP_QUE_MASK);
+    write_conf_bits(dev, queue, COMP_QUE_OFFSET, COMP_QUE_MASK);
 }
 
-int16_t ads111x_get_comp_low_thresh(uint8_t addr)
+int16_t ads111x_get_comp_low_thresh(i2c_dev_t* dev)
 {
-    return read_reg(addr, REG_THRESH_L);
+    return read_reg(dev, REG_THRESH_L);
 }
 
-void ads111x_set_comp_low_thresh(uint8_t addr, int16_t thresh)
+void ads111x_set_comp_low_thresh(i2c_dev_t* dev, int16_t thresh)
 {
-    write_reg(addr, REG_THRESH_L, thresh);
+    write_reg(dev, REG_THRESH_L, thresh);
 }
 
-int16_t ads111x_get_comp_high_thresh(uint8_t addr)
+int16_t ads111x_get_comp_high_thresh(i2c_dev_t* dev)
 {
-    return read_reg(addr, REG_THRESH_H);
+    return read_reg(dev, REG_THRESH_H);
 }
 
-void ads111x_set_comp_high_thresh(uint8_t addr, int16_t thresh)
+void ads111x_set_comp_high_thresh(i2c_dev_t* dev, int16_t thresh)
 {
-    write_reg(addr, REG_THRESH_H, thresh);
+    write_reg(dev, REG_THRESH_H, thresh);
 }
diff --git a/extras/ads111x/ads111x.h b/extras/ads111x/ads111x.h
index fe64464..af93d4e 100644
--- a/extras/ads111x/ads111x.h
+++ b/extras/ads111x/ads111x.h
@@ -10,6 +10,7 @@
 
 #include <stdint.h>
 #include <stdbool.h>
+#include <i2c/i2c.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -124,20 +125,20 @@ typedef enum
  * @param addr Deivce address
  * @return true when device performing conversion
  */
-bool ads111x_busy(uint8_t addr);
+bool ads111x_busy(i2c_dev_t* dev);
 
 /**
  * Begin a single conversion (when in single-shot mode)
  * @param addr Deivce address
  */
-void ads111x_start_conversion(uint8_t addr);
+void ads111x_start_conversion(i2c_dev_t* dev);
 
 /**
  * Read last conversion result
  * @param addr
  * @return Last conversion result
  */
-int16_t ads111x_get_value(uint8_t addr);
+int16_t ads111x_get_value(i2c_dev_t* dev);
 
 /**
  * Read the programmable gain amplifier configuration
@@ -145,70 +146,70 @@ int16_t ads111x_get_value(uint8_t addr);
  * @param addr Deivce address
  * @return Gain value
  */
-ads111x_gain_t ads111x_get_gain(uint8_t addr);
+ads111x_gain_t ads111x_get_gain(i2c_dev_t* dev);
 
 /**
  * Configure the programmable gain amplifier (ADS1114 and ADS1115 only)
  * @param addr Deivce address
  * @param gain Gain value
  */
-void ads111x_set_gain(uint8_t addr, ads111x_gain_t gain);
+void ads111x_set_gain(i2c_dev_t* dev, ads111x_gain_t gain);
 
 /**
  * Read the input multiplexer configuration (ADS1115 only)
  * @param addr Deivce address
  * @return Input multiplexer configuration
  */
-ads111x_mux_t ads111x_get_input_mux(uint8_t addr);
+ads111x_mux_t ads111x_get_input_mux(i2c_dev_t* dev);
 
 /**
  * Configure the input multiplexer configuration (ADS1115 only)
  * @param addr Deivce address
  * @param mux Input multiplexer configuration
  */
-void ads111x_set_input_mux(uint8_t addr, ads111x_mux_t mux);
+void ads111x_set_input_mux(i2c_dev_t* dev, ads111x_mux_t mux);
 
 /**
  * Read the device operating mode
  * @param addr Deivce address
  * @return Device operating mode
  */
-ads111x_mode_t ads111x_get_mode(uint8_t addr);
+ads111x_mode_t ads111x_get_mode(i2c_dev_t* dev);
 
 /**
  * Set the device operating mode
  * @param addr Deivce address
  * @param mode Device operating mode
  */
-void ads111x_set_mode(uint8_t addr, ads111x_mode_t mode);
+void ads111x_set_mode(i2c_dev_t* dev, ads111x_mode_t mode);
 
 /**
  * Read the data rate
  * @param addr Deivce address
  * @return Data rate
  */
-ads111x_data_rate_t ads111x_get_data_rate(uint8_t addr);
+ads111x_data_rate_t ads111x_get_data_rate(i2c_dev_t* dev);
 
 /**
  * Configure the data rate
  * @param addr Deivce address
  * @param rate Data rate
  */
-void ads111x_set_data_rate(uint8_t addr, ads111x_data_rate_t rate);
+void ads111x_set_data_rate(i2c_dev_t* dev, ads111x_data_rate_t rate);
 
 /**
  * Get comparator mode (ADS1114 and ADS1115 only)
  * @param addr Deivce address
  * @return Comparator mode
  */
-ads111x_comp_mode_t ads111x_get_comp_mode(uint8_t addr);
+ads111x_comp_mode_t ads111x_get_comp_mode(i2c_dev_t* dev);
 
 /**
  * Set comparator mode (ADS1114 and ADS1115 only)
  * @param addr Deivce address
  * @param mode Comparator mode
  */
-void ads111x_set_comp_mode(uint8_t addr, ads111x_comp_mode_t mode);
+void ads111x_set_comp_mode(i2c_dev_t* dev, ads111x_comp_mode_t mode);
 
 /**
  * Get polarity of the comparator output pin ALERT/RDY
@@ -216,7 +217,7 @@ void ads111x_set_comp_mode(uint8_t addr, ads111x_comp_mode_t mode);
  * @param addr Deivce address
  * @return Comparator output pin polarity
  */
-ads111x_comp_polarity_t ads111x_get_comp_polarity(uint8_t addr);
+ads111x_comp_polarity_t ads111x_get_comp_polarity(i2c_dev_t* dev);
 
 /**
  * Set polarity of the comparator output pin ALERT/RDY
@@ -224,7 +225,7 @@ ads111x_comp_polarity_t ads111x_get_comp_polarity(uint8_t addr);
  * @param addr Deivce address
  * @param polarity Comparator output pin polarity
  */
-void ads111x_set_comp_polarity(uint8_t addr, ads111x_comp_polarity_t polarity);
+void ads111x_set_comp_polarity(i2c_dev_t* dev, ads111x_comp_polarity_t polarity);
 
 /**
  * Get comparator output latch mode, see datasheet.
@@ -232,14 +233,14 @@ void ads111x_set_comp_polarity(uint8_t addr, ads111x_comp_polarity_t polarity);
  * @param addr Deivce address
  * @return Comparator output latch mode
  */
-ads111x_comp_latch_t ads111x_get_comp_latch(uint8_t addr);
+ads111x_comp_latch_t ads111x_get_comp_latch(i2c_dev_t* dev);
 
 /**
  * Set comparator output latch mode (ADS1114 and ADS1115 only)
  * @param addr Deivce address
  * @param latch Comparator output latch mode
  */
-void ads111x_set_comp_latch(uint8_t addr, ads111x_comp_latch_t latch);
+void ads111x_set_comp_latch(i2c_dev_t* dev, ads111x_comp_latch_t latch);
 
 /**
  * Set number of the comparator conversions before pin ALERT/RDY
@@ -247,7 +248,7 @@ void ads111x_set_comp_latch(uint8_t addr, ads111x_comp_latch_t latch);
  * @param addr Deivce address
  * @return Number of the comparator conversions
  */
-ads111x_comp_queue_t ads111x_get_comp_queue(uint8_t addr);
+ads111x_comp_queue_t ads111x_get_comp_queue(i2c_dev_t* dev);
 
 /**
  * Get number of the comparator conversions before pin ALERT/RDY
@@ -255,35 +256,35 @@ ads111x_comp_queue_t ads111x_get_comp_queue(uint8_t addr);
  * @param addr Deivce address
  * @param queue Number of the comparator conversions
  */
-void ads111x_set_comp_queue(uint8_t addr, ads111x_comp_queue_t queue);
+void ads111x_set_comp_queue(i2c_dev_t* dev, ads111x_comp_queue_t queue);
 
 /**
  * Get the lower threshold value used by comparator
  * @param addr Deivce address
  * @return Lower threshold value
  */
-int16_t ads111x_get_comp_low_thresh(uint8_t addr);
+int16_t ads111x_get_comp_low_thresh(i2c_dev_t* dev);
 
 /**
  * Set the lower threshold value used by comparator
  * @param addr Deivce address
  * @param thresh Lower threshold value
  */
-void ads111x_set_comp_low_thresh(uint8_t addr, int16_t thresh);
+void ads111x_set_comp_low_thresh(i2c_dev_t* dev, int16_t thresh);
 
 /**
  * Get the upper threshold value used by comparator
  * @param addr Deivce address
  * @return Upper threshold value
  */
-int16_t ads111x_get_comp_high_thresh(uint8_t addr);
+int16_t ads111x_get_comp_high_thresh(i2c_dev_t* dev);
 
 /**
  * Set the upper threshold value used by comparator
  * @param addr Deivce address
  * @param thresh Upper threshold value
  */
-void ads111x_set_comp_high_thresh(uint8_t addr, int16_t thresh);
+void ads111x_set_comp_high_thresh(i2c_dev_t* dev, int16_t thresh);
 
 #ifdef __cplusplus
 }
diff --git a/extras/bh1750/bh1750.c b/extras/bh1750/bh1750.c
index 68e623a..51860d0 100644
--- a/extras/bh1750/bh1750.c
+++ b/extras/bh1750/bh1750.c
@@ -6,20 +6,19 @@
  * BSD Licensed as described in the file LICENSE
  */
 #include "bh1750.h"
-#include <i2c/i2c.h>
 #include <stdio.h>
 
-void bh1750_configure(uint8_t addr, uint8_t mode)
+void bh1750_configure(i2c_dev_t *dev, uint8_t mode)
 {
-	i2c_slave_write(addr, NULL, &mode, 1);
+	i2c_slave_write(dev->bus, dev->addr, NULL, &mode, 1);
 }
 
-uint16_t bh1750_read(uint8_t addr)
+uint16_t bh1750_read(i2c_dev_t *dev)
 {
 	uint8_t buf[2];
 	uint16_t level;
 
-	i2c_slave_read(addr, NULL, buf, 2);
+	i2c_slave_read(dev->bus, dev->addr, NULL, buf, 2);
 
 	level = buf[0] << 8 | buf[1];
 	level = (level * 10) / 12; // convert to LUX
diff --git a/extras/bh1750/bh1750.h b/extras/bh1750/bh1750.h
index b280c45..a6bcae6 100644
--- a/extras/bh1750/bh1750.h
+++ b/extras/bh1750/bh1750.h
@@ -13,6 +13,7 @@
 #include <stdint.h>
 #include <stdbool.h>
 #include <time.h>
+#include <i2c/i2c.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -65,7 +66,7 @@ extern "C" {
  *
  * Example: BH1750_ADDR_LO, BH1750_CONTINUOUS_MODE | BH1750_HIGH_RES_MODE
  */
-void bh1750_configure(uint8_t addr, uint8_t mode);
+void bh1750_configure(i2c_dev_t *dev, uint8_t mode);
 
 /**
  * Read LUX value from the device.
@@ -73,7 +74,7 @@ void bh1750_configure(uint8_t addr, uint8_t mode);
  * @param addr Device address
  * @returns read value in lux units
  */
-uint16_t bh1750_read(uint8_t addr);
+uint16_t bh1750_read(i2c_dev_t *dev);
 
 #ifdef __cplusplus
 }
diff --git a/extras/ds3231/ds3231.c b/extras/ds3231/ds3231.c
index 41d453a..dfc5757 100644
--- a/extras/ds3231/ds3231.c
+++ b/extras/ds3231/ds3231.c
@@ -11,9 +11,6 @@
 #include "espressif/sdk_private.h"
 #include "esp8266.h"
 
-#include "i2c/i2c.h"
-
-static uint8_t _bus;
 
 /* Convert normal decimal to binary coded decimal */
 static inline uint8_t  decToBcd(uint8_t dec)
@@ -30,20 +27,20 @@ static inline uint8_t  bcdToDec(uint8_t bcd)
 /* Send a number of bytes to the rtc over i2c
  * returns true to indicate success
  */
-static inline int ds3231_send(uint8_t reg, uint8_t *data, uint8_t len)
+static inline int ds3231_send(i2c_dev_t *dev, uint8_t reg, uint8_t *data, uint8_t len)
 {
-    return i2c_slave_write(_bus, DS3231_ADDR, &reg, data, len);
+    return i2c_slave_write(dev->bus, dev->addr, &reg, data, len);
 }
 
 /* Read a number of bytes from the rtc over i2c
  * returns true to indicate success
  */
-static inline int ds3231_recv(uint8_t reg, uint8_t *data, uint8_t len)
+static inline int ds3231_recv(i2c_dev_t *dev, uint8_t reg, uint8_t *data, uint8_t len)
 {
-    return i2c_slave_read(_bus, DS3231_ADDR, &reg, data, len);
+    return i2c_slave_read(dev->bus, dev->addr, &reg, data, len);
 }
 
-int ds3231_setTime(struct tm *time)
+int ds3231_setTime(i2c_dev_t *dev, struct tm *time)
 {
     uint8_t data[7];
 
@@ -56,10 +53,10 @@ int ds3231_setTime(struct tm *time)
     data[5] = decToBcd(time->tm_mon + 1);
     data[6] = decToBcd(time->tm_year - 100);
 
-    return ds3231_send(DS3231_ADDR_TIME, data, 7);
+    return ds3231_send(dev, DS3231_ADDR_TIME, data, 7);
 }
 
-int ds3231_setAlarm(uint8_t alarms, struct tm *time1, uint8_t option1, struct tm *time2, uint8_t option2)
+int ds3231_setAlarm(i2c_dev_t *dev, uint8_t alarms, struct tm *time1, uint8_t option1, struct tm *time2, uint8_t option2)
 {
     int i = 0;
     uint8_t data[7];
@@ -83,7 +80,7 @@ int ds3231_setAlarm(uint8_t alarms, struct tm *time1, uint8_t option1, struct tm
             (option2 == DS3231_ALARM2_MATCH_MINHOURDATE ? decToBcd(time2->tm_mday) : DS3231_ALARM_NOTSET));
     }
 
-    return ds3231_send((alarms == DS3231_ALARM_2 ? DS3231_ADDR_ALARM2 : DS3231_ADDR_ALARM1), data, i);
+    return ds3231_send(dev, (alarms == DS3231_ALARM_2 ? DS3231_ADDR_ALARM2 : DS3231_ADDR_ALARM1), data, i);
 }
 
 /* Get a byte containing just the requested bits
@@ -93,12 +90,12 @@ int ds3231_setAlarm(uint8_t alarms, struct tm *time1, uint8_t option1, struct tm
  * of use a mask of 0xff to just return the whole register byte
  * returns true to indicate success
  */
-bool ds3231_getFlag(uint8_t addr, uint8_t mask, uint8_t *flag)
+bool ds3231_getFlag(i2c_dev_t *dev, uint8_t addr, uint8_t mask, uint8_t *flag)
 {
     uint8_t data;
 
     /* get register */
-    if (!ds3231_recv(addr, &data, 1))
+    if (!ds3231_recv(dev, addr, &data, 1))
     {
         /* return only requested flag */
         *flag = (data & mask);
@@ -114,12 +111,12 @@ bool ds3231_getFlag(uint8_t addr, uint8_t mask, uint8_t *flag)
  * DS3231_SET/DS3231_CLEAR/DS3231_REPLACE
  * returns true to indicate success
  */
-bool ds3231_setFlag(uint8_t addr, uint8_t bits, uint8_t mode)
+bool ds3231_setFlag(i2c_dev_t *dev, uint8_t addr, uint8_t bits, uint8_t mode)
 {
     uint8_t data;
 
     /* get status register */
-    if (!ds3231_recv(addr, &data, 1))
+    if (!ds3231_recv(dev, addr, &data, 1))
     {
         /* clear the flag */
         if (mode == DS3231_REPLACE)
@@ -129,18 +126,18 @@ bool ds3231_setFlag(uint8_t addr, uint8_t bits, uint8_t mode)
         else
             data &= ~bits;
 
-        if (!ds3231_send(addr, &data, 1))
+        if (!ds3231_send(dev, addr, &data, 1))
             return true;
     }
 
     return false;
 }
 
-bool ds3231_getOscillatorStopFlag(bool *flag)
+bool ds3231_getOscillatorStopFlag(i2c_dev_t *dev, bool *flag)
 {
     uint8_t f;
 
-    if (ds3231_getFlag(DS3231_ADDR_STATUS, DS3231_STAT_OSCILLATOR, &f))
+    if (ds3231_getFlag(dev, DS3231_ADDR_STATUS, DS3231_STAT_OSCILLATOR, &f))
     {
         *flag = (f ? true : false);
         return true;
@@ -149,76 +146,76 @@ bool ds3231_getOscillatorStopFlag(bool *flag)
     return false;
 }
 
-inline bool ds3231_clearOscillatorStopFlag()
+inline bool ds3231_clearOscillatorStopFlag(i2c_dev_t *dev)
 {
-    return ds3231_setFlag(DS3231_ADDR_STATUS, DS3231_STAT_OSCILLATOR, DS3231_CLEAR);
+    return ds3231_setFlag(dev, DS3231_ADDR_STATUS, DS3231_STAT_OSCILLATOR, DS3231_CLEAR);
 }
 
-inline bool ds3231_getAlarmFlags(uint8_t *alarms)
+inline bool ds3231_getAlarmFlags(i2c_dev_t *dev, uint8_t *alarms)
 {
-    return ds3231_getFlag(DS3231_ADDR_STATUS, DS3231_ALARM_BOTH, alarms);
+    return ds3231_getFlag(dev, DS3231_ADDR_STATUS, DS3231_ALARM_BOTH, alarms);
 }
 
-inline bool ds3231_clearAlarmFlags(uint8_t alarms)
+inline bool ds3231_clearAlarmFlags(i2c_dev_t *dev, uint8_t alarms)
 {
-    return ds3231_setFlag(DS3231_ADDR_STATUS, alarms, DS3231_CLEAR);
+    return ds3231_setFlag(dev, DS3231_ADDR_STATUS, alarms, DS3231_CLEAR);
 }
 
-inline bool ds3231_enableAlarmInts(uint8_t alarms)
+inline bool ds3231_enableAlarmInts(i2c_dev_t *dev, uint8_t alarms)
 {
-    return ds3231_setFlag(DS3231_ADDR_CONTROL, DS3231_CTRL_ALARM_INTS | alarms, DS3231_SET);
+    return ds3231_setFlag(dev, DS3231_ADDR_CONTROL, DS3231_CTRL_ALARM_INTS | alarms, DS3231_SET);
 }
 
-inline bool ds3231_disableAlarmInts(uint8_t alarms)
+inline bool ds3231_disableAlarmInts(i2c_dev_t *dev, uint8_t alarms)
 {
     /* Just disable specific alarm(s) requested
      * does not disable alarm interrupts generally (which would enable the squarewave)
      */
-    return ds3231_setFlag(DS3231_ADDR_CONTROL, alarms, DS3231_CLEAR);
+    return ds3231_setFlag(dev, DS3231_ADDR_CONTROL, alarms, DS3231_CLEAR);
 }
 
-inline bool ds3231_enable32khz()
+inline bool ds3231_enable32khz(i2c_dev_t *dev)
 {
-    return ds3231_setFlag(DS3231_ADDR_STATUS, DS3231_STAT_32KHZ, DS3231_SET);
+    return ds3231_setFlag(dev, DS3231_ADDR_STATUS, DS3231_STAT_32KHZ, DS3231_SET);
 }
 
-inline bool ds3231_disable32khz()
+inline bool ds3231_disable32khz(i2c_dev_t *dev)
 {
-    return ds3231_setFlag(DS3231_ADDR_STATUS, DS3231_STAT_32KHZ, DS3231_CLEAR);
+    return ds3231_setFlag(dev, DS3231_ADDR_STATUS, DS3231_STAT_32KHZ, DS3231_CLEAR);
 }
 
-inline bool ds3231_enableSquarewave()
+inline bool ds3231_enableSquarewave(i2c_dev_t *dev)
 {
-    return ds3231_setFlag(DS3231_ADDR_CONTROL, DS3231_CTRL_ALARM_INTS, DS3231_CLEAR);
+    return ds3231_setFlag(dev, DS3231_ADDR_CONTROL, DS3231_CTRL_ALARM_INTS, DS3231_CLEAR);
 }
 
-inline bool ds3231_disableSquarewave()
+inline bool ds3231_disableSquarewave(i2c_dev_t *dev)
 {
-    return ds3231_setFlag(DS3231_ADDR_CONTROL, DS3231_CTRL_ALARM_INTS, DS3231_SET);
+    return ds3231_setFlag(dev, DS3231_ADDR_CONTROL, DS3231_CTRL_ALARM_INTS, DS3231_SET);
 }
 
-bool ds3231_setSquarewaveFreq(uint8_t freq)
+bool ds3231_setSquarewaveFreq(i2c_dev_t *dev, uint8_t freq)
 {
     uint8_t flag = 0;
 
-    if (ds3231_getFlag(DS3231_ADDR_CONTROL, 0xff, &flag))
+    if (ds3231_getFlag(dev, DS3231_ADDR_CONTROL, 0xff, &flag))
     {
         /* clear current rate */
         flag &= ~DS3231_CTRL_SQWAVE_8192HZ;
         /* set new rate */
         flag |= freq;
 
-        return ds3231_setFlag(DS3231_ADDR_CONTROL, flag, DS3231_REPLACE);
+        return ds3231_setFlag(dev, DS3231_ADDR_CONTROL, flag, DS3231_REPLACE);
     }
     return false;
 }
 
-bool ds3231_getRawTemp(int16_t *temp)
+bool ds3231_getRawTemp(i2c_dev_t *dev, int16_t *temp)
 {
     uint8_t data[2];
 
     data[0] = DS3231_ADDR_TEMP;
-    if (!ds3231_recv(DS3231_ADDR_TEMP,data, 2))
+    if (!ds3231_recv(dev, DS3231_ADDR_TEMP,data, 2))
     {
         *temp = (int16_t)(int8_t)data[0] << 2 | data[1] >> 6;
         return true;
@@ -227,11 +224,11 @@ bool ds3231_getRawTemp(int16_t *temp)
     return false;
 }
 
-bool ds3231_getTempInteger(int8_t *temp)
+bool ds3231_getTempInteger(i2c_dev_t *dev, int8_t *temp)
 {
     int16_t tInt;
 
-    if (ds3231_getRawTemp(&tInt)) {
+    if (ds3231_getRawTemp(dev, &tInt)) {
         *temp = tInt >> 2;
         return true;
     }
@@ -239,11 +236,11 @@ bool ds3231_getTempInteger(int8_t *temp)
     return false;
 }
 
-bool ds3231_getTempFloat(float *temp)
+bool ds3231_getTempFloat(i2c_dev_t *dev, float *temp)
 {
     int16_t tInt;
 
-    if (ds3231_getRawTemp(&tInt)) {
+    if (ds3231_getRawTemp(dev, &tInt)) {
         *temp = tInt * 0.25;
         return true;
     }
@@ -251,12 +248,12 @@ bool ds3231_getTempFloat(float *temp)
     return false;
 }
 
-bool ds3231_getTime(struct tm *time)
+bool ds3231_getTime(i2c_dev_t *dev, struct tm *time)
 {
     uint8_t data[7];
 
     /* read time */
-    if (ds3231_recv(DS3231_ADDR_TIME, data, 7))
+    if (ds3231_recv(dev, DS3231_ADDR_TIME, data, 7))
     {
         return false;
     }
@@ -285,9 +282,3 @@ bool ds3231_getTime(struct tm *time)
     return true;
 
 }
-
-void ds3231_Init(uint8_t bus)
-{
-    _bus = bus;
-    //i2c_init(0, scl, sda);
-}
diff --git a/extras/ds3231/ds3231.h b/extras/ds3231/ds3231.h
index 39c1466..6ef9ff7 100644
--- a/extras/ds3231/ds3231.h
+++ b/extras/ds3231/ds3231.h
@@ -12,6 +12,8 @@
 #include <stdint.h>
 #include <stdbool.h>
 #include <time.h>
+#include "i2c/i2c.h"
+
 
 #ifdef	__cplusplus
 extern "C" {
@@ -87,7 +89,7 @@ enum {
  * I suggest using GMT and applying timezone and DST when read back
  * returns true to indicate success
  */
-int ds3231_setTime(struct tm *time);
+int ds3231_setTime(i2c_dev_t *dev, struct tm *time);
 
 /* Set alarms
  * alarm1 works with seconds, minutes, hours and day of week/month, or fires every second
@@ -100,30 +102,30 @@ int ds3231_setTime(struct tm *time);
  * if you want to enable interrupts for the alarms you need to do that separately
  * returns true to indicate success
  */
-int ds3231_setAlarm(uint8_t alarms, struct tm *time1, uint8_t option1, struct tm *time2, uint8_t option2);
+int ds3231_setAlarm(i2c_dev_t *dev, uint8_t alarms, struct tm *time1, uint8_t option1, struct tm *time2, uint8_t option2);
 
 /* Check if oscillator has previously stopped, e.g. no power/battery or disabled
  * sets flag to true if there has been a stop
  * returns true to indicate success
  */
-bool ds3231_getOscillatorStopFlag(bool *flag);
+bool ds3231_getOscillatorStopFlag(i2c_dev_t *dev, bool *flag);
 
 /* Clear the oscillator stopped flag
  * returns true to indicate success
  */
-bool ds3231_clearOscillatorStopFlag();
+bool ds3231_clearOscillatorStopFlag(i2c_dev_t *dev);
 
 /* Check which alarm(s) have past
  * sets alarms to DS3231_ALARM_NONE/DS3231_ALARM_1/DS3231_ALARM_2/DS3231_ALARM_BOTH
  * returns true to indicate success
  */
-bool ds3231_getAlarmFlags(uint8_t *alarms);
+bool ds3231_getAlarmFlags(i2c_dev_t *dev, uint8_t *alarms);
 
 /* Clear alarm past flag(s)
  * pass DS3231_ALARM_1/DS3231_ALARM_2/DS3231_ALARM_BOTH
  * returns true to indicate success
  */
-bool ds3231_clearAlarmFlags(uint8_t alarm);
+bool ds3231_clearAlarmFlags(i2c_dev_t *dev, uint8_t alarm);
 
 /* enable alarm interrupts (and disables squarewave)
  * pass DS3231_ALARM_1/DS3231_ALARM_2/DS3231_ALARM_BOTH
@@ -132,61 +134,60 @@ bool ds3231_clearAlarmFlags(uint8_t alarm);
  * interrupt enabled, else it will trigger immediately
  * returns true to indicate success
  */
-bool ds3231_enableAlarmInts(uint8_t alarms);
+bool ds3231_enableAlarmInts(i2c_dev_t *dev, uint8_t alarms);
 
 /* Disable alarm interrupts (does not (re-)enable squarewave)
  * pass DS3231_ALARM_1/DS3231_ALARM_2/DS3231_ALARM_BOTH
  * returns true to indicate success
  */
-bool ds3231_disableAlarmInts(uint8_t alarms);
+bool ds3231_disableAlarmInts(i2c_dev_t *dev, uint8_t alarms);
 
 /* Enable the output of 32khz signal
  * returns true to indicate success
  */
-bool ds3231_enable32khz();
+bool ds3231_enable32khz(i2c_dev_t *dev);
 
 /* Disable the output of 32khz signal
  * returns true to indicate success
  */
-bool ds3231_disable32khz();
+bool ds3231_disable32khz(i2c_dev_t *dev);
 
 /* Enable the squarewave output (disables alarm interrupt functionality)
  * returns true to indicate success
  */
-bool ds3231_enableSquarewave();
+bool ds3231_enableSquarewave(i2c_dev_t *dev);
 
 /* Disable the squarewave output (which re-enables alarm interrupts, but individual
  * alarm interrupts also need to be enabled, if not already, before they will trigger)
  * returns true to indicate success
  */
-bool ds3231_disableSquarewave();
+bool ds3231_disableSquarewave(i2c_dev_t *dev);
 
 /* Set the frequency of the squarewave output (but does not enable it)
  * pass DS3231_SQUAREWAVE_RATE_1HZ/DS3231_SQUAREWAVE_RATE_1024HZ/DS3231_SQUAREWAVE_RATE_4096HZ/DS3231_SQUAREWAVE_RATE_8192HZ
  * returns true to indicate success
  */
-bool ds3231_setSquarewaveFreq(uint8_t freq);
+bool ds3231_setSquarewaveFreq(i2c_dev_t *dev, uint8_t freq);
 
 /* Get the raw value
  * returns true to indicate success
  */
-bool ds3231_getRawTemp(int16_t *temp);
+bool ds3231_getRawTemp(i2c_dev_t *dev, int16_t *temp);
 
 /* Get the temperature as an integer
  * returns true to indicate success
  */
-bool ds3231_getTempInteger(int8_t *temp);
+bool ds3231_getTempInteger(i2c_dev_t *dev, int8_t *temp);
 
 /* Get the temerapture as a float (in quarter degree increments)
  * returns true to indicate success
  */
-bool ds3231_getTempFloat(float *temp);
+bool ds3231_getTempFloat(i2c_dev_t *dev, float *temp);
 
 /* Get the time from the rtc, populates a supplied tm struct
  * returns true to indicate success
  */
-bool ds3231_getTime(struct tm *time);
-void ds3231_Init(uint8_t bus);
+bool ds3231_getTime(i2c_dev_t *dev, struct tm *time);
 
 #ifdef	__cplusplus
 }
diff --git a/extras/i2c/i2c.c b/extras/i2c/i2c.c
index 066f8ac..d519735 100644
--- a/extras/i2c/i2c.c
+++ b/extras/i2c/i2c.c
@@ -66,7 +66,7 @@ void i2c_init(uint8_t bus, uint8_t scl_pin, uint8_t sda_pin, uint8_t freq)
 
     // Prevent user, if frequency is high
     if (sdk_system_get_cpu_freq() == SYS_CPU_80MHZ)
-        if (I2C_CUSTOM_DELAY_80MHZ == 1)
+        if (i2c_freq_array[i2c_bus[bus].frequency][1] == 1)
             debug("Max frequency is 320Khz at 80MHz");
 
 }
@@ -130,12 +130,12 @@ static inline void clear_sda(uint8_t bus)
 // Output start condition
 void i2c_start(uint8_t bus)
 {
-    uint32_t clk_stretch = CLK_STRETCH;
     freq = sdk_system_get_cpu_freq();
     if (i2c_bus[bus].started) { // if started, do a restart cond
         // Set SDA to 1
         (void) read_sda(bus);
         i2c_delay(bus);
+        uint32_t clk_stretch = CLK_STRETCH;
         while (read_scl(bus) == 0 && clk_stretch--) ;
         // Repeated start setup time, minimum 4.7us
         i2c_delay(bus);
@@ -229,7 +229,7 @@ uint8_t i2c_read(uint8_t bus, bool ack)
     uint8_t byte = 0;
     uint8_t bit;
     for (bit = 0; bit < 8; bit++) {
-        byte = (byte << 1) | i2c_read_bit(bus);
+        byte = ((byte << 1)) | (i2c_read_bit(bus));
     }
     i2c_write_bit(bus,ack);
     return byte;
diff --git a/extras/i2c/i2c.h b/extras/i2c/i2c.h
index 156b76a..065323d 100644
--- a/extras/i2c/i2c.h
+++ b/extras/i2c/i2c.h
@@ -51,8 +51,17 @@ extern "C" {
 
 const static uint8_t i2c_freq_array[3][2] = { {100,20}, {10,1}, {6,1} } ;
 
+/**
+ * Device descriptor
+ */
+typedef struct i2c_dev {
+  uint8_t bus ;
+  uint8_t addr ;
+} i2c_dev_t ;
 
-
+/**
+ * Bus settings
+ */
 typedef struct i2c_bus_description {
   uint8_t g_scl_pin;  // Scl pin
   uint8_t g_sda_pin;  // Sda pin