diff --git a/common/pimoroni_common.hpp b/common/pimoroni_common.hpp
index 30ccc268..9f372c11 100644
--- a/common/pimoroni_common.hpp
+++ b/common/pimoroni_common.hpp
@@ -6,9 +6,10 @@
 #define PIMORONI_SPI_DEFAULT_INSTANCE spi0
 
 namespace pimoroni {
-    static const unsigned int PIN_UNUSED = UINT_MAX;
+    static const unsigned int PIN_UNUSED = INT_MAX; // Intentionally INT_MAX to avoid overflowing MicroPython's int type
 
     // I2C
+    static const unsigned int I2C_DEFAULT_BAUDRATE = 400000;
     static const unsigned int I2C_DEFAULT_SDA = 20;
     static const unsigned int I2C_DEFAULT_SCL = 21;
     static const unsigned int I2C_DEFAULT_INT = 22;
diff --git a/common/pimoroni_i2c.cpp b/common/pimoroni_i2c.cpp
index c4f2e724..52fcda61 100644
--- a/common/pimoroni_i2c.cpp
+++ b/common/pimoroni_i2c.cpp
@@ -5,7 +5,7 @@ namespace pimoroni {
     void I2C::init() {
         i2c = ((sda / 2) & 0b1) ? i2c1 : i2c0;
 
-        i2c_init(i2c, 400000);
+        i2c_init(i2c, baudrate);
 
         gpio_set_function(sda, GPIO_FUNC_I2C); gpio_pull_up(sda);
         gpio_set_function(scl, GPIO_FUNC_I2C); gpio_pull_up(scl);
@@ -29,7 +29,28 @@ namespace pimoroni {
     uint8_t I2C::reg_read_uint8(uint8_t address, uint8_t reg) {
         uint8_t value;
         i2c_write_blocking(i2c, address, &reg, 1, false);
-        i2c_read_blocking(i2c, address, (uint8_t *)&value, 1, false);
+        i2c_read_blocking(i2c, address, (uint8_t *)&value, sizeof(uint8_t), false);
+        return value;
+    }
+
+    uint16_t I2C::reg_read_uint16(uint8_t address, uint8_t reg) {
+        uint16_t value;
+        i2c_write_blocking(i2c, address, &reg, 1, true);
+        i2c_read_blocking(i2c, address, (uint8_t *)&value, sizeof(uint16_t), false);
+        return value;
+    }
+
+    uint32_t I2C::reg_read_uint32(uint8_t address, uint8_t reg) {
+        uint32_t value;
+        i2c_write_blocking(i2c, address, &reg, 1, true);
+        i2c_read_blocking(i2c, address, (uint8_t *)&value, sizeof(uint32_t), false);
+        return value;
+    }
+
+    int16_t I2C::reg_read_int16(uint8_t address, uint8_t reg) {
+        int16_t value;
+        i2c_write_blocking(i2c, address, &reg, 1, true);
+        i2c_read_blocking(i2c, address, (uint8_t *)&value, sizeof(int16_t), false);
         return value;
     }
 
@@ -67,11 +88,4 @@ namespace pimoroni {
         value &= ~(mask << shift);
         write_bytes(address, reg, &value, 1);
     }
-
-    int16_t I2C::reg_read_int16(uint8_t address, uint8_t reg) {
-        int16_t value;
-        i2c_write_blocking(i2c, address, &reg, 1, true);
-        i2c_read_blocking(i2c, address, (uint8_t *)&value, 2, false);
-        return value;
-    }
 }
\ No newline at end of file
diff --git a/common/pimoroni_i2c.hpp b/common/pimoroni_i2c.hpp
index 28eb4157..87146c8e 100644
--- a/common/pimoroni_i2c.hpp
+++ b/common/pimoroni_i2c.hpp
@@ -13,9 +13,10 @@ namespace pimoroni {
         uint sda = I2C_DEFAULT_SDA;
         uint scl = I2C_DEFAULT_SCL;
         uint interrupt = PIN_UNUSED;
+        uint32_t baudrate = I2C_DEFAULT_BAUDRATE;
 
       public:
-        I2C(BOARD board) {
+        I2C(BOARD board, uint32_t baudrate = I2C_DEFAULT_BAUDRATE) : baudrate(baudrate) {
           switch(board) {
             case BREAKOUT_GARDEN:
               sda = I2C_BG_SDA;
@@ -32,10 +33,12 @@ namespace pimoroni {
           init();
         }
 
-        I2C(uint sda, uint scl) : sda(sda), scl(scl) {
+        I2C(uint sda, uint scl, uint32_t baudrate = I2C_DEFAULT_BAUDRATE) : sda(sda), scl(scl), baudrate(baudrate) {
           init();
         }
 
+        I2C() : I2C(I2C_DEFAULT_SDA, I2C_DEFAULT_SCL) {}
+
         ~I2C() {
           i2c_deinit(i2c);
           gpio_disable_pulls(sda);
@@ -46,7 +49,9 @@ namespace pimoroni {
 
         void reg_write_uint8(uint8_t address, uint8_t reg, uint8_t value);
         uint8_t reg_read_uint8(uint8_t address, uint8_t reg);
+        uint16_t reg_read_uint16(uint8_t address, uint8_t reg);
         int16_t reg_read_int16(uint8_t address, uint8_t reg);
+        uint32_t reg_read_uint32(uint8_t address, uint8_t reg);
 
         int write_bytes(uint8_t address, uint8_t reg, uint8_t *buf, int len);
         int read_bytes(uint8_t address, uint8_t reg, uint8_t *buf, int len);
@@ -60,6 +65,7 @@ namespace pimoroni {
         i2c_inst_t* get_i2c() {return i2c;}
         uint get_scl() {return scl;}
         uint get_sda() {return sda;}
+        uint32_t get_baudrate() {return baudrate;}
       private:
         void init();
     };
diff --git a/drivers/as7262/as7262.hpp b/drivers/as7262/as7262.hpp
index d2e4a75e..5a46471e 100644
--- a/drivers/as7262/as7262.hpp
+++ b/drivers/as7262/as7262.hpp
@@ -15,10 +15,6 @@ namespace pimoroni {
     //--------------------------------------------------
   public:
     static const uint8_t DEFAULT_I2C_ADDRESS  = 0x49;
-    static const uint8_t DEFAULT_SDA_PIN      = 20;
-    static const uint8_t DEFAULT_SCL_PIN      = 21;
-    static const uint8_t DEFAULT_INT_PIN      = 22;
-    static const uint8_t PIN_UNUSED           = UINT8_MAX;
 
 
     //--------------------------------------------------
@@ -76,24 +72,17 @@ namespace pimoroni {
 
     // interface pins with our standard defaults where appropriate
     int8_t address    = DEFAULT_I2C_ADDRESS;
-    int8_t interrupt  = DEFAULT_INT_PIN;
+    uint interrupt  = PIN_UNUSED;
 
 
     //--------------------------------------------------
     // Constructors/Destructor
     //--------------------------------------------------
   public:
-    AS7262() {
-      i2c = new I2C(DEFAULT_SDA_PIN, DEFAULT_SCL_PIN);
-    };
-    AS7262(uint8_t address) : address(address) {
-      i2c = new I2C(DEFAULT_SDA_PIN, DEFAULT_SCL_PIN);
-    };
-    AS7262(i2c_inst_t *i2c_inst, uint8_t address, uint sda, uint scl, uint8_t interrupt = PIN_UNUSED) : address(address), interrupt(interrupt) {
-      i2c = new I2C(sda, scl);
-    }
-    AS7262(I2C *i2c, uint8_t address = DEFAULT_I2C_ADDRESS, uint8_t interrupt = PIN_UNUSED) :
-      i2c(i2c), address(address), interrupt(interrupt) {}
+    AS7262() : AS7262(DEFAULT_I2C_ADDRESS) {};
+    AS7262(uint8_t address) : i2c(new I2C()), address(address) {};
+    AS7262(i2c_inst_t *i2c_inst, uint8_t address, uint sda, uint scl, uint interrupt = PIN_UNUSED) : i2c(new I2C()), address(address), interrupt(interrupt) {}
+    AS7262(I2C *i2c, uint8_t address = DEFAULT_I2C_ADDRESS, uint interrupt = PIN_UNUSED) : i2c(i2c), address(address), interrupt(interrupt) {}
 
 
     //--------------------------------------------------
diff --git a/drivers/ioexpander/ioexpander.cpp b/drivers/ioexpander/ioexpander.cpp
index 14709f25..c1d7756a 100644
--- a/drivers/ioexpander/ioexpander.cpp
+++ b/drivers/ioexpander/ioexpander.cpp
@@ -298,18 +298,18 @@ namespace pimoroni {
   }
 
   IOExpander::IOExpander() :
-    IOExpander(new I2C(DEFAULT_SDA_PIN, DEFAULT_SCL_PIN), DEFAULT_I2C_ADDRESS, DEFAULT_INT_PIN, timeout, debug) {};
+    IOExpander(new I2C(), DEFAULT_I2C_ADDRESS, DEFAULT_INT_PIN, timeout, debug) {};
 
   IOExpander::IOExpander(uint8_t address, uint32_t timeout, bool debug) :
-    IOExpander(new I2C(DEFAULT_SDA_PIN, DEFAULT_SCL_PIN), address, DEFAULT_INT_PIN, timeout, debug) {};
+    IOExpander(new I2C(), address, DEFAULT_INT_PIN, timeout, debug) {};
 
-  IOExpander::IOExpander(uint8_t address, uint8_t sda, uint8_t scl, uint8_t interrupt, uint32_t timeout, bool debug) :
+  IOExpander::IOExpander(uint8_t address, uint sda, uint scl, uint interrupt, uint32_t timeout, bool debug) :
     IOExpander(new I2C(sda, scl), address, interrupt, timeout, debug) {};
 
-  IOExpander::IOExpander(i2c_inst_t *i2c, uint8_t address, uint8_t sda, uint8_t scl, uint8_t interrupt, uint32_t timeout, bool debug) :
+  IOExpander::IOExpander(i2c_inst_t *i2c, uint8_t address, uint sda, uint scl, uint interrupt, uint32_t timeout, bool debug) :
     IOExpander(new I2C(sda, scl), address, interrupt, timeout, debug) {};
 
-  IOExpander::IOExpander(I2C *i2c, uint8_t address, uint8_t interrupt, uint32_t timeout, bool debug) :
+  IOExpander::IOExpander(I2C *i2c, uint8_t address, uint interrupt, uint32_t timeout, bool debug) :
     i2c(i2c),
     address(address), interrupt(interrupt),
     timeout(timeout), debug(debug), vref(3.3f),
diff --git a/drivers/ioexpander/ioexpander.hpp b/drivers/ioexpander/ioexpander.hpp
index da0c790b..dfee4047 100644
--- a/drivers/ioexpander/ioexpander.hpp
+++ b/drivers/ioexpander/ioexpander.hpp
@@ -148,7 +148,7 @@ namespace pimoroni {
 
     // interface pins with our standard defaults where appropriate
     int8_t address    = DEFAULT_I2C_ADDRESS;
-    int8_t interrupt  = DEFAULT_INT_PIN;
+    uint interrupt  = DEFAULT_INT_PIN;
 
     uint32_t timeout;
     bool debug;
@@ -164,9 +164,9 @@ namespace pimoroni {
   public:
     IOExpander();
     IOExpander(uint8_t address, uint32_t timeout = 1, bool debug = false);
-    IOExpander(uint8_t address, uint8_t sda, uint8_t scl, uint8_t interrupt = PIN_UNUSED, uint32_t timeout = 1, bool debug = false);
-    IOExpander(i2c_inst_t *i2c, uint8_t address, uint8_t sda, uint8_t scl, uint8_t interrupt = PIN_UNUSED, uint32_t timeout = 1, bool debug = false);
-    IOExpander(I2C *i2c, uint8_t address=DEFAULT_I2C_ADDRESS, uint8_t interrupt = PIN_UNUSED, uint32_t timeout = 1, bool debug = false);
+    IOExpander(uint8_t address, uint sda, uint scl, uint interrupt = PIN_UNUSED, uint32_t timeout = 1, bool debug = false);
+    IOExpander(i2c_inst_t *i2c, uint8_t address, uint sda, uint scl, uint interrupt = PIN_UNUSED, uint32_t timeout = 1, bool debug = false);
+    IOExpander(I2C *i2c, uint8_t address=DEFAULT_I2C_ADDRESS, uint interrupt = PIN_UNUSED, uint32_t timeout = 1, bool debug = false);
 
 
     //--------------------------------------------------
diff --git a/drivers/ltr559/ltr559.hpp b/drivers/ltr559/ltr559.hpp
index 7bc352b6..f32fa700 100644
--- a/drivers/ltr559/ltr559.hpp
+++ b/drivers/ltr559/ltr559.hpp
@@ -112,10 +112,6 @@ namespace pimoroni {
     //--------------------------------------------------
   public:
     static const uint8_t DEFAULT_I2C_ADDRESS    = 0x23;
-    static const uint8_t DEFAULT_SDA_PIN        = 20;
-    static const uint8_t DEFAULT_SCL_PIN        = 21;
-    static const uint8_t DEFAULT_INT_PIN        = 22;
-    static const uint8_t PIN_UNUSED             = UINT8_MAX;
 
   private:
     const int ch0_c[4] = {17743, 42785, 5926, 0};
@@ -133,7 +129,7 @@ namespace pimoroni {
 
     // interface pins with our standard defaults where appropriate
     uint8_t address    = DEFAULT_I2C_ADDRESS;
-    uint8_t interrupt  = DEFAULT_INT_PIN;
+    uint interrupt     = PIN_UNUSED;
 
     static pimoroni::lookup lookup_led_current; 
     static pimoroni::lookup lookup_led_duty_cycle;
@@ -148,16 +144,10 @@ namespace pimoroni {
     // Constructors/Destructor
     //--------------------------------------------------
   public:
-    LTR559() {
-      i2c = new I2C(DEFAULT_SDA_PIN, DEFAULT_SCL_PIN);
-    };
-    LTR559(uint8_t address) : address(address) {
-      i2c = new I2C(DEFAULT_SDA_PIN, DEFAULT_SCL_PIN);
-    };
-    LTR559(i2c_inst_t *i2c_inst, uint8_t address, uint sda, uint scl, uint8_t interrupt = PIN_UNUSED) : address(address), interrupt(interrupt) {
-      i2c = new I2C(sda, scl);
-    }
-    LTR559(I2C *i2c, uint8_t address = DEFAULT_I2C_ADDRESS, uint8_t interrupt = PIN_UNUSED) :
+    LTR559() : LTR559(DEFAULT_I2C_ADDRESS) {};
+    LTR559(uint8_t address) : i2c(new I2C()), address(address) {};
+    LTR559(i2c_inst_t *i2c_inst, uint8_t address, uint sda, uint scl, uint interrupt = PIN_UNUSED) : i2c(new I2C()), address(address), interrupt(interrupt) {}
+    LTR559(I2C *i2c, uint8_t address = DEFAULT_I2C_ADDRESS, uint interrupt = PIN_UNUSED) :
       i2c(i2c), address(address), interrupt(interrupt) {}
 
     //--------------------------------------------------
diff --git a/drivers/msa301/msa301.hpp b/drivers/msa301/msa301.hpp
index 7200e593..bab102e6 100644
--- a/drivers/msa301/msa301.hpp
+++ b/drivers/msa301/msa301.hpp
@@ -13,10 +13,6 @@ namespace pimoroni {
     //--------------------------------------------------
   public:
     static const uint8_t DEFAULT_I2C_ADDRESS    = 0x26;
-    static const uint8_t DEFAULT_SDA_PIN        = 20;
-    static const uint8_t DEFAULT_SCL_PIN        = 21;
-    static const uint8_t DEFAULT_INT_PIN        = 22;
-    static const uint8_t PIN_UNUSED             = UINT8_MAX;
     
     static const uint8_t SOFT_RESET             = 0x00;
     static const uint8_t PART_ID                = 0x01;
@@ -109,26 +105,17 @@ namespace pimoroni {
     //--------------------------------------------------
   private:
     I2C *i2c;
-
-    // interface pins with our standard defaults where appropriate
-    uint8_t address    = DEFAULT_I2C_ADDRESS;
-    uint interrupt    = I2C_DEFAULT_INT;
+    uint8_t address  = DEFAULT_I2C_ADDRESS;
+    uint interrupt   = PIN_UNUSED;
 
     //--------------------------------------------------
     // Constructors/Destructor
     //--------------------------------------------------
   public:
-    MSA301() {
-      i2c = new I2C(DEFAULT_SDA_PIN, DEFAULT_SCL_PIN);
-    };
-    MSA301(uint8_t address) : address(address) {
-      i2c = new I2C(DEFAULT_SDA_PIN, DEFAULT_SCL_PIN);
-    };
-    MSA301(i2c_inst_t *i2c_inst, uint8_t address, uint sda, uint scl, uint8_t interrupt = PIN_UNUSED) : address(address), interrupt(interrupt) {
-      i2c = new I2C(sda, scl);
-    }
-    MSA301(I2C *i2c, uint8_t address = DEFAULT_I2C_ADDRESS, uint interrupt = PIN_UNUSED) :
-      i2c(i2c), address(address), interrupt(interrupt) {}
+    MSA301() : MSA301(DEFAULT_I2C_ADDRESS) {};
+    MSA301(uint8_t address) : i2c(new I2C()), address(address) {};
+    MSA301(i2c_inst_t *i2c_inst, uint8_t address, uint sda, uint scl, uint interrupt = PIN_UNUSED) : i2c(new I2C(sda, scl)), address(address), interrupt(interrupt) {}
+    MSA301(I2C *i2c, uint8_t address = DEFAULT_I2C_ADDRESS, uint interrupt = PIN_UNUSED) : i2c(i2c), address(address), interrupt(interrupt) {}
 
 
     //--------------------------------------------------
diff --git a/drivers/sgp30/sgp30.hpp b/drivers/sgp30/sgp30.hpp
index 20c937a5..08f9de91 100644
--- a/drivers/sgp30/sgp30.hpp
+++ b/drivers/sgp30/sgp30.hpp
@@ -18,8 +18,6 @@ namespace pimoroni {
     //--------------------------------------------------
   public:
     static const uint8_t DEFAULT_I2C_ADDRESS  = 0x58;
-    static const uint8_t DEFAULT_SDA_PIN      = 20;
-    static const uint8_t DEFAULT_SCL_PIN      = 21;
 
   private:
     /***** Private constants here *****/
@@ -48,20 +46,11 @@ namespace pimoroni {
     // Constructors/Destructor
     //--------------------------------------------------
   public:
-    SGP30() {
-      i2c = new I2C(DEFAULT_SDA_PIN, DEFAULT_SCL_PIN);
-    };
-    SGP30(uint8_t address) : address(address) {
-      i2c = new I2C(DEFAULT_SDA_PIN, DEFAULT_SCL_PIN);
-    };
-    SGP30(i2c_inst_t *i2c_inst, uint sda, uint scl) {
-      i2c = new I2C(sda, scl);
-    }
-    SGP30(i2c_inst_t *i2c_inst, uint8_t address, uint sda, uint scl) : address(address) {
-      i2c = new I2C(sda, scl);
-    }
-    SGP30(I2C *i2c, uint8_t address = DEFAULT_I2C_ADDRESS, uint interrupt = PIN_UNUSED) :
-      i2c(i2c), address(address) {}
+    SGP30() : SGP30(DEFAULT_I2C_ADDRESS) {};
+    SGP30(uint8_t address) : i2c(new I2C()), address(address) {};
+    SGP30(i2c_inst_t *i2c_inst, uint sda, uint scl) : i2c(new I2C(sda, scl)) { }
+    SGP30(i2c_inst_t *i2c_inst, uint8_t address, uint sda, uint scl) : i2c(new I2C(sda, scl)) , address(address) {}
+    SGP30(I2C *i2c, uint8_t address = DEFAULT_I2C_ADDRESS, uint interrupt = PIN_UNUSED) : i2c(i2c), address(address) {}
 
     //--------------------------------------------------
     // Methods
diff --git a/drivers/trackball/trackball.cmake b/drivers/trackball/trackball.cmake
index 97e54570..d5e13c89 100644
--- a/drivers/trackball/trackball.cmake
+++ b/drivers/trackball/trackball.cmake
@@ -7,4 +7,4 @@ target_sources(${DRIVER_NAME} INTERFACE
 target_include_directories(${DRIVER_NAME} INTERFACE ${CMAKE_CURRENT_LIST_DIR})
 
 # Pull in pico libraries that we need
-target_link_libraries(${DRIVER_NAME} INTERFACE pico_stdlib hardware_i2c)
+target_link_libraries(${DRIVER_NAME} INTERFACE pico_stdlib hardware_i2c pimoroni_i2c)
diff --git a/drivers/trackball/trackball.cpp b/drivers/trackball/trackball.cpp
index d806456f..7551c3a6 100644
--- a/drivers/trackball/trackball.cpp
+++ b/drivers/trackball/trackball.cpp
@@ -42,12 +42,9 @@ namespace pimoroni {
   bool Trackball::init() {
     bool succeeded = false;
 
-    i2c_init(i2c, 100000);
-
-    gpio_set_function(sda, GPIO_FUNC_I2C);
-    gpio_pull_up(sda);
-    gpio_set_function(scl, GPIO_FUNC_I2C);
-    gpio_pull_up(scl);
+    if(i2c->get_baudrate() > 100000) {
+      return false;
+    }
 
     if(interrupt != PIN_UNUSED) {
       gpio_set_function(interrupt, GPIO_FUNC_SIO);
@@ -55,7 +52,7 @@ namespace pimoroni {
       gpio_pull_up(interrupt);
     }
 
-    uint16_t chip_id = ((uint16_t)i2c_reg_read_uint8(reg::CHIP_ID_H) << 8) | (uint16_t)i2c_reg_read_uint8(reg::CHIP_ID_L);
+    uint16_t chip_id = ((uint16_t)i2c->reg_read_uint8(address, reg::CHIP_ID_H) << 8) | (uint16_t)i2c->reg_read_uint8(address, reg::CHIP_ID_L);
     if(chip_id == CHIP_ID) {
       enable_interrupt();
       succeeded = true;
@@ -65,7 +62,7 @@ namespace pimoroni {
   }
 
   i2c_inst_t* Trackball::get_i2c() const {
-    return i2c;
+    return i2c->get_i2c();
   }
 
   int Trackball::get_address() const {
@@ -73,11 +70,11 @@ namespace pimoroni {
   }
 
   int Trackball::get_sda() const {
-    return sda;
+    return i2c->get_sda();
   }
 
   int Trackball::get_scl() const {
-    return scl;
+    return i2c->get_scl();
   }
 
   int Trackball::get_int() const {
@@ -85,17 +82,17 @@ namespace pimoroni {
   }
 
   void Trackball::change_address(uint8_t new_address) {
-    i2c_reg_write_uint8(reg::I2C_ADDR, new_address);
+    i2c->reg_write_uint8(address, reg::I2C_ADDR, new_address);
     wait_for_flash();
   }
   
   void Trackball::enable_interrupt(bool use_interrupt) {
-    uint8_t value = i2c_reg_read_uint8(reg::INT);
+    uint8_t value = i2c->reg_read_uint8(address, reg::INT);
     value &= ~MSK_INT_OUT_EN;
     if(use_interrupt)
       value |= MSK_INT_OUT_EN;
 
-    i2c_reg_write_uint8(reg::INT, value);
+    i2c->reg_write_uint8(address, reg::INT, value);
   }
   
   bool Trackball::get_interrupt() {
@@ -105,61 +102,49 @@ namespace pimoroni {
       value = !gpio_get(interrupt);
     }
     else {
-      value = i2c_reg_read_uint8(reg::INT);
+      value = i2c->reg_read_uint8(address, reg::INT);
       value &= MSK_INT_TRIGGERED;
     }
     return false;
   }
 
   void Trackball::set_rgbw(uint8_t r, uint8_t g, uint8_t b, uint8_t w) {
-    i2c_reg_write_uint8(reg::LED_RED, r);
-    i2c_reg_write_uint8(reg::LED_GRN, g);
-    i2c_reg_write_uint8(reg::LED_BLU, b);
-    i2c_reg_write_uint8(reg::LED_WHT, w);
+    i2c->reg_write_uint8(address, reg::LED_RED, r);
+    i2c->reg_write_uint8(address, reg::LED_GRN, g);
+    i2c->reg_write_uint8(address, reg::LED_BLU, b);
+    i2c->reg_write_uint8(address, reg::LED_WHT, w);
   }
 
   void Trackball::set_red(uint8_t value) {
-    i2c_reg_write_uint8(reg::LED_RED, value);
+    i2c->reg_write_uint8(address, reg::LED_RED, value);
   }
 
   void Trackball::set_green(uint8_t value) {
-    i2c_reg_write_uint8(reg::LED_GRN, value);
+    i2c->reg_write_uint8(address, reg::LED_GRN, value);
   }
 
   void Trackball::set_blue(uint8_t value) {
-    i2c_reg_write_uint8(reg::LED_BLU, value);
+    i2c->reg_write_uint8(address, reg::LED_BLU, value);
   }
 
   void Trackball::set_white(uint8_t value) {
-    i2c_reg_write_uint8(reg::LED_WHT, value);
+    i2c->reg_write_uint8(address, reg::LED_WHT, value);
   }
 
   Trackball::State Trackball::read() {
     State state;
     uint8_t sw_state;
-    state.left = i2c_reg_read_uint8(reg::LEFT);
-    state.right = i2c_reg_read_uint8(reg::RIGHT);
-    state.up = i2c_reg_read_uint8(reg::UP);
-    state.down = i2c_reg_read_uint8(reg::DOWN);
-    sw_state = i2c_reg_read_uint8(reg::SWITCH);
+    state.left = i2c->reg_read_uint8(address, reg::LEFT);
+    state.right = i2c->reg_read_uint8(address, reg::RIGHT);
+    state.up = i2c->reg_read_uint8(address, reg::UP);
+    state.down = i2c->reg_read_uint8(address, reg::DOWN);
+    sw_state = i2c->reg_read_uint8(address, reg::SWITCH);
 
     state.sw_changed = sw_state & ~MSK_SWITCH_STATE;
     state.sw_pressed = (sw_state  & MSK_SWITCH_STATE) > 0;
     return state;
   }
 
-  uint8_t Trackball::i2c_reg_read_uint8(uint8_t reg) {
-    uint8_t value;
-    i2c_write_blocking(i2c, address, &reg, 1, true);
-    i2c_read_blocking(i2c, address, (uint8_t *)&value, 1, false);
-    return value;
-  }
-
-  void Trackball::i2c_reg_write_uint8(uint8_t reg, uint8_t value) {
-    uint8_t buffer[2] = {reg, value};
-    i2c_write_blocking(i2c, address, buffer, 2, false);
-  }
-
   void Trackball::wait_for_flash(void) {
     unsigned long start_time = millis();
     while(get_interrupt()) {
diff --git a/drivers/trackball/trackball.hpp b/drivers/trackball/trackball.hpp
index 4e82e1c8..3defdef5 100644
--- a/drivers/trackball/trackball.hpp
+++ b/drivers/trackball/trackball.hpp
@@ -2,6 +2,7 @@
 
 #include "hardware/i2c.h"
 #include "hardware/gpio.h"
+#include "common/pimoroni_i2c.hpp"
 
 namespace pimoroni {
 
@@ -12,11 +13,7 @@ namespace pimoroni {
   public:
     static const uint8_t DEFAULT_I2C_ADDRESS        = 0x0A;
     static const uint8_t I2C_ADDRESS_ALTERNATIVE    = 0x0B;
-    static const uint8_t DEFAULT_SDA_PIN            = 20;
-    static const uint8_t DEFAULT_SCL_PIN            = 21;
-    static const uint8_t DEFAULT_INT_PIN            = 22;
     static const uint32_t DEFAULT_TIMEOUT           = 5;
-    static const uint8_t PIN_UNUSED                 = UINT8_MAX;
 
   private:
     static const uint16_t CHIP_ID = 0xBA11;
@@ -41,13 +38,9 @@ namespace pimoroni {
     // Variables
     //--------------------------------------------------
   private:
-    i2c_inst_t *i2c     = i2c0;
-
-    // interface pins with our standard defaults where appropriate
+    I2C *i2c;
     int8_t address      = DEFAULT_I2C_ADDRESS;
-    int8_t sda          = DEFAULT_SDA_PIN;
-    int8_t scl          = DEFAULT_SCL_PIN;
-    int8_t interrupt    = DEFAULT_INT_PIN;
+    uint interrupt      = PIN_UNUSED;
     uint32_t timeout    = DEFAULT_TIMEOUT;
 
 
@@ -55,13 +48,10 @@ namespace pimoroni {
     // Constructors/Destructor
     //--------------------------------------------------
   public:
-    Trackball() {};
-
-    Trackball(uint8_t address) :
-      address(address) {}
-
-    Trackball(i2c_inst_t *i2c, uint8_t address, uint8_t sda, uint8_t scl, uint8_t interrupt = PIN_UNUSED, uint32_t timeout = DEFAULT_TIMEOUT) :
-      i2c(i2c), address(address), sda(sda), scl(scl), interrupt(interrupt), timeout(timeout) {}
+    Trackball() : Trackball(DEFAULT_I2C_ADDRESS) {};
+    Trackball(uint8_t address) : i2c(new I2C()), address(address) {};
+    Trackball(i2c_inst_t *i2c_inst, uint8_t address, uint sda, uint scl, uint interrupt = PIN_UNUSED, uint32_t timeout = DEFAULT_TIMEOUT) : i2c(new I2C(sda, scl)), address(address), interrupt(interrupt) {}
+    Trackball(I2C *i2c, uint8_t address = DEFAULT_I2C_ADDRESS, uint interrupt = PIN_UNUSED, uint32_t timeout = DEFAULT_TIMEOUT) : i2c(i2c), address(address), interrupt(interrupt) {}
 
 
     //--------------------------------------------------
@@ -88,9 +78,6 @@ namespace pimoroni {
     State read();
 
   private:
-    uint8_t i2c_reg_read_uint8(uint8_t reg);
-    void i2c_reg_write_uint8(uint8_t reg, uint8_t value);
-
     void wait_for_flash();
 
     uint32_t millis();
diff --git a/drivers/vl53l1x/CMakeLists.txt b/drivers/vl53l1x/CMakeLists.txt
index 7d5060ad..eff5eb25 100644
--- a/drivers/vl53l1x/CMakeLists.txt
+++ b/drivers/vl53l1x/CMakeLists.txt
@@ -7,4 +7,4 @@ target_sources(vl53l1x INTERFACE
 target_include_directories(vl53l1x INTERFACE ${CMAKE_CURRENT_LIST_DIR})
 
 # Pull in pico libraries that we need
-target_link_libraries(vl53l1x INTERFACE pico_stdlib hardware_i2c)
+target_link_libraries(vl53l1x INTERFACE pico_stdlib hardware_i2c pimoroni_i2c)
diff --git a/drivers/vl53l1x/vl53l1x.cpp b/drivers/vl53l1x/vl53l1x.cpp
index a38c4833..d50be0ac 100644
--- a/drivers/vl53l1x/vl53l1x.cpp
+++ b/drivers/vl53l1x/vl53l1x.cpp
@@ -37,12 +37,6 @@ namespace pimoroni {
     saved_vhv_timeout = 0;
     // distance_mode = 1;
 
-    // Initialise I2C connection
-    i2c_init(i2c, 400000);
-
-    gpio_set_function(sda, GPIO_FUNC_I2C); gpio_pull_up(sda);
-    gpio_set_function(scl, GPIO_FUNC_I2C); gpio_pull_up(scl);
-
     last_status = 0;
 
     // check model ID and module type registers (values specified in datasheet)
@@ -169,14 +163,14 @@ namespace pimoroni {
   void VL53L1X::writeReg(uint16_t reg, uint8_t value)
   {
     uint8_t buffer[3] = {(reg >> 8) & 0xFF, reg & 0xFF, value};
-    i2c_write_blocking(i2c, address, buffer, 3, false);
+    i2c->write_blocking(address, buffer, 3, false);
   }
 
   // Write a 16-bit register
   void VL53L1X::writeReg16Bit(uint16_t reg, uint16_t value)
   {
     uint8_t buffer[4] = {(reg >> 8) & 0xFF, reg & 0xFF, (value >> 8) & 0xFF, value & 0xFF};
-    i2c_write_blocking(i2c, address, buffer, 4, false);
+    i2c->write_blocking(address, buffer, 4, false);
   }
 
   // Write a 32-bit register
@@ -184,7 +178,7 @@ namespace pimoroni {
   {
     uint8_t buffer[6] = {(reg >> 8) & 0xFF, reg & 0xFF,
       (value >> 24) & 0xFF, (value >> 16) & 0xFF, (value >> 8) & 0xFF, value & 0xFF};
-    i2c_write_blocking(i2c, address, buffer, 6, false);
+    i2c->write_blocking(address, buffer, 6, false);
   }
 
   // Read an 8-bit register
@@ -193,8 +187,8 @@ namespace pimoroni {
     uint8_t regbuf[2] = {((uint8_t)reg >> 8) & 0xFF, (uint8_t)reg & 0xFF};
     uint8_t buffer[1];
     uint8_t value;
-    i2c_write_blocking(i2c, address, regbuf, 2, true);
-    i2c_read_blocking(i2c, address, buffer, 1, false);
+    i2c->write_blocking(address, regbuf, 2, true);
+    i2c->read_blocking(address, buffer, 1, false);
     value = buffer[0];
     return value;
   }
@@ -206,8 +200,8 @@ namespace pimoroni {
     uint8_t buffer[2];
     uint16_t value;
     reg= (reg << 8) + (reg >> 8);
-    i2c_write_blocking(i2c, address, regbuf, 2, true);
-    i2c_read_blocking(i2c, address, buffer, 2, false);
+    i2c->write_blocking(address, regbuf, 2, true);
+    i2c->read_blocking(address, buffer, 2, false);
     value= (buffer[0] << 8) + buffer[1];
     return value;
   }
@@ -219,8 +213,8 @@ namespace pimoroni {
     uint8_t buffer[4];
     uint32_t value;
     reg= (reg << 8) + (reg >> 8);
-    i2c_write_blocking(i2c, address, regbuf, 2, true);
-    i2c_read_blocking(i2c, address, buffer, 4, false);
+    i2c->write_blocking(address, regbuf, 2, true);
+    i2c->read_blocking(address, buffer, 4, false);
     value= (buffer[0] << 24) + (buffer[1] << 16) + (buffer[2] << 8) + buffer[3];
     return value;
   }
@@ -580,8 +574,8 @@ namespace pimoroni {
     uint16_t reg = RESULT__RANGE_STATUS;
     uint8_t regbuf[2] = {(reg >> 8) & 0xFF, reg & 0xFF};
     uint8_t buffer[17];
-    i2c_write_blocking(i2c, address, regbuf, 2, true);
-    i2c_read_blocking(i2c, address, buffer, 17, false);
+    i2c->write_blocking(address, regbuf, 2, true);
+    i2c->read_blocking(address, buffer, 17, false);
 
     results.range_status = buffer[0];
 
diff --git a/drivers/vl53l1x/vl53l1x.hpp b/drivers/vl53l1x/vl53l1x.hpp
index 85231667..d108bb0c 100644
--- a/drivers/vl53l1x/vl53l1x.hpp
+++ b/drivers/vl53l1x/vl53l1x.hpp
@@ -15,17 +15,17 @@ Distributed as-is; no warranty is given.
 
 #include <stdio.h>
 #include "pico/stdlib.h"
+#include "common/pimoroni_i2c.hpp"
 
 namespace pimoroni {
 
   class VL53L1X {
+    static const uint8_t DEFAULT_I2C_ADDRESS  = 0x29;
 
-    i2c_inst_t *i2c = i2c0;
+    I2C *i2c;
 
-    int8_t address   = 0x29;
-    int8_t sda       = 20;
-    int8_t scl       = 21;
-    int8_t interrupt = 22;
+    int8_t address   = DEFAULT_I2C_ADDRESS;
+    uint interrupt = 22;
 
     // register addresses from API vl53l1x_register_map.h
     enum regAddr : uint16_t
@@ -1291,7 +1291,10 @@ namespace pimoroni {
     uint8_t last_status; // status of last I2C transmission
 
   public:
-    VL53L1X() {}
+    VL53L1X() : VL53L1X(DEFAULT_I2C_ADDRESS) {};
+    VL53L1X(uint8_t address) : i2c(new I2C()), address(address) {};
+    VL53L1X(i2c_inst_t *i2c_inst, uint8_t address, uint sda, uint scl, uint interrupt = PIN_UNUSED) : i2c(new I2C()), address(address), interrupt(interrupt) {}
+    VL53L1X(I2C *i2c, uint8_t address = DEFAULT_I2C_ADDRESS, uint interrupt = PIN_UNUSED) : i2c(i2c), address(address), interrupt(interrupt) {}
 
     uint16_t getid();
     uint16_t getosc();
diff --git a/examples/breakout_ltr559/demo.cpp b/examples/breakout_ltr559/demo.cpp
index 6c6770ae..276f6690 100644
--- a/examples/breakout_ltr559/demo.cpp
+++ b/examples/breakout_ltr559/demo.cpp
@@ -5,7 +5,7 @@
 
 using namespace pimoroni;
 
-I2C i2c(4, 5);
+I2C i2c(BOARD::BREAKOUT_GARDEN);
 BreakoutLTR559 ltr559(&i2c);
 
 int main() {
@@ -14,7 +14,13 @@ int main() {
   ltr559.init();
 
   uint8_t part_id = ltr559.part_id();
-  printf("Found LTR559. Part ID: 0x%02x\n", part_id);
+  if(part_id == LTR559_VALID_PART_ID) {
+    printf("Found LTR559. Part ID: 0x%02x\n", part_id);
+  }
+  else
+  {
+    printf("Could not find LTR559. Got Part ID: 0x%02x, expected 0x%02x\n", part_id, LTR559_VALID_PART_ID);
+  }
 
   while(true){
     bool new_data = ltr559.get_reading();
diff --git a/examples/breakout_trackball/demo.cpp b/examples/breakout_trackball/demo.cpp
index 2a1f7ed7..2d08f62d 100644
--- a/examples/breakout_trackball/demo.cpp
+++ b/examples/breakout_trackball/demo.cpp
@@ -7,11 +7,19 @@ using namespace pimoroni;
 
 static const uint8_t SENSITIVITY = 2;
 
-
-BreakoutTrackball trackball;
+// Trackball requires I2C at 100kHz or less.
+I2C i2c(BOARD::BREAKOUT_GARDEN, 100000);
+BreakoutTrackball trackball(&i2c);
 
 int main() {
-  trackball.init();
+  stdio_init_all();
+
+  if(!trackball.init()) {
+    printf("Trackball failed to init!\n");
+    return 1;
+  }
+
+  printf("Roll the Trackball to change colour!\n");
 
   trackball.set_rgbw(0, 0, 0, 64);
 
diff --git a/libraries/breakout_colourlcd160x80/breakout_colourlcd160x80.cpp b/libraries/breakout_colourlcd160x80/breakout_colourlcd160x80.cpp
index c2f035d8..bfa71ff4 100644
--- a/libraries/breakout_colourlcd160x80/breakout_colourlcd160x80.cpp
+++ b/libraries/breakout_colourlcd160x80/breakout_colourlcd160x80.cpp
@@ -8,7 +8,7 @@ namespace pimoroni {
   }
 
   BreakoutColourLCD160x80::BreakoutColourLCD160x80(uint16_t *buf, spi_inst_t *spi,
-      uint8_t cs, uint8_t dc, uint8_t sck, uint8_t mosi, uint8_t miso, uint8_t bl)
+      uint cs, uint dc, uint sck, uint mosi, uint miso, uint bl)
     : PicoGraphics(WIDTH, HEIGHT, buf), screen(WIDTH, HEIGHT, buf, spi, cs, dc, sck, mosi, miso, bl) {
     __fb = buf;
   }
diff --git a/libraries/breakout_colourlcd160x80/breakout_colourlcd160x80.hpp b/libraries/breakout_colourlcd160x80/breakout_colourlcd160x80.hpp
index f08c4e18..8db78425 100644
--- a/libraries/breakout_colourlcd160x80/breakout_colourlcd160x80.hpp
+++ b/libraries/breakout_colourlcd160x80/breakout_colourlcd160x80.hpp
@@ -13,8 +13,6 @@ namespace pimoroni {
   public:
     static const int WIDTH            = 160;
     static const int HEIGHT           = 80;
-    static const uint8_t PIN_UNUSED   = UINT8_MAX;
-
 
     //--------------------------------------------------
     // Variables
@@ -31,7 +29,7 @@ namespace pimoroni {
   public:
     BreakoutColourLCD160x80(uint16_t *buf);
     BreakoutColourLCD160x80(uint16_t *buf, spi_inst_t *spi,
-      uint8_t cs, uint8_t dc, uint8_t sck, uint8_t mosi, uint8_t miso = PIN_UNUSED, uint8_t bl = PIN_UNUSED);
+      uint cs, uint dc, uint sck, uint mosi, uint miso = PIN_UNUSED, uint bl = PIN_UNUSED);
     BreakoutColourLCD160x80(uint16_t *buf, BG_SPI_SLOT slot);
 
 
diff --git a/libraries/breakout_colourlcd240x240/breakout_colourlcd240x240.cpp b/libraries/breakout_colourlcd240x240/breakout_colourlcd240x240.cpp
index 83427e72..6be2a581 100644
--- a/libraries/breakout_colourlcd240x240/breakout_colourlcd240x240.cpp
+++ b/libraries/breakout_colourlcd240x240/breakout_colourlcd240x240.cpp
@@ -8,7 +8,7 @@ namespace pimoroni {
   }
 
   BreakoutColourLCD240x240::BreakoutColourLCD240x240(uint16_t *buf,  spi_inst_t *spi,
-      uint8_t cs, uint8_t dc, uint8_t sck, uint8_t mosi, uint8_t miso, uint8_t bl)
+      uint cs, uint dc, uint sck, uint mosi, uint miso, uint bl)
     : PicoGraphics(WIDTH, HEIGHT, buf), screen(WIDTH, HEIGHT, buf, spi, cs, dc, sck, mosi, miso, bl)  {
     __fb = buf;
   }
diff --git a/libraries/breakout_colourlcd240x240/breakout_colourlcd240x240.hpp b/libraries/breakout_colourlcd240x240/breakout_colourlcd240x240.hpp
index 524db9e0..2b63e586 100644
--- a/libraries/breakout_colourlcd240x240/breakout_colourlcd240x240.hpp
+++ b/libraries/breakout_colourlcd240x240/breakout_colourlcd240x240.hpp
@@ -13,8 +13,6 @@ namespace pimoroni {
   public:
     static const int WIDTH = 240;
     static const int HEIGHT = 240;
-    static const uint8_t PIN_UNUSED   = UINT8_MAX;
-
 
     //--------------------------------------------------
     // Variables
@@ -31,7 +29,7 @@ namespace pimoroni {
   public:
     BreakoutColourLCD240x240(uint16_t *buf);
     BreakoutColourLCD240x240(uint16_t *buf,  spi_inst_t *spi,
-      uint8_t cs, uint8_t dc, uint8_t sck, uint8_t mosi, uint8_t miso = PIN_UNUSED, uint8_t bl = PIN_UNUSED);
+      uint cs, uint dc, uint sck, uint mosi, uint miso = PIN_UNUSED, uint bl = PIN_UNUSED);
     BreakoutColourLCD240x240(uint16_t *buf,  BG_SPI_SLOT slot);
     
 
diff --git a/libraries/breakout_encoder/breakout_encoder.hpp b/libraries/breakout_encoder/breakout_encoder.hpp
index f925ba04..f69cb676 100644
--- a/libraries/breakout_encoder/breakout_encoder.hpp
+++ b/libraries/breakout_encoder/breakout_encoder.hpp
@@ -47,7 +47,7 @@ namespace pimoroni {
     IOExpander ioe;
     Direction direction = DEFAULT_DIRECTION;
     float brightness = DEFAULT_BRIGHTNESS;
-    uint8_t interrupt_pin = PIN_UNUSED;     // A local copy of the value passed to the IOExpander, used in initialisation
+    uint interrupt_pin = PIN_UNUSED;     // A local copy of the value passed to the IOExpander, used in initialisation
 
 
     //--------------------------------------------------
@@ -60,10 +60,10 @@ namespace pimoroni {
     BreakoutEncoder(uint8_t address) :
       ioe(address) {}
 
-    BreakoutEncoder(I2C *i2c, uint8_t address = DEFAULT_I2C_ADDRESS, uint8_t interrupt = PIN_UNUSED, uint32_t timeout = DEFAULT_TIMEOUT, bool debug = false) :
+    BreakoutEncoder(I2C *i2c, uint8_t address = DEFAULT_I2C_ADDRESS, uint interrupt = PIN_UNUSED, uint32_t timeout = DEFAULT_TIMEOUT, bool debug = false) :
       ioe(i2c, address, interrupt, timeout, debug) {}
 
-    BreakoutEncoder(i2c_inst_t *i2c, uint8_t address, uint8_t sda, uint8_t scl, uint8_t interrupt = PIN_UNUSED, uint32_t timeout = DEFAULT_TIMEOUT) :
+    BreakoutEncoder(i2c_inst_t *i2c, uint8_t address, uint8_t sda, uint8_t scl, uint interrupt = PIN_UNUSED, uint32_t timeout = DEFAULT_TIMEOUT) :
       ioe(i2c, address, sda, scl, interrupt, timeout),
       interrupt_pin(interrupt) {}
 
diff --git a/micropython/modules/breakout_as7262/breakout_as7262.cpp b/micropython/modules/breakout_as7262/breakout_as7262.cpp
index a0dd8621..c17ad413 100644
--- a/micropython/modules/breakout_as7262/breakout_as7262.cpp
+++ b/micropython/modules/breakout_as7262/breakout_as7262.cpp
@@ -47,9 +47,9 @@ mp_obj_t BreakoutAS7262_make_new(const mp_obj_type_t *type, size_t n_args, size_
     enum { ARG_i2c, ARG_sda, ARG_scl, ARG_int };
     static const mp_arg_t allowed_args[] = {
         { MP_QSTR_i2c, MP_ARG_INT, {.u_int = -1} },
-        { MP_QSTR_sda, MP_ARG_INT, {.u_int = 20} },
-        { MP_QSTR_scl, MP_ARG_INT, {.u_int = 21} },
-        { MP_QSTR_interrupt, MP_ARG_INT, {.u_int = BreakoutAS7262::PIN_UNUSED} },
+        { MP_QSTR_sda, MP_ARG_INT, {.u_int = I2C_DEFAULT_SDA} },
+        { MP_QSTR_scl, MP_ARG_INT, {.u_int = I2C_DEFAULT_SCL} },
+        { MP_QSTR_interrupt, MP_ARG_INT, {.u_int = PIN_UNUSED} },
     };
 
     // Parse args.
diff --git a/micropython/modules/breakout_colourlcd160x80/breakout_colourlcd160x80.cpp b/micropython/modules/breakout_colourlcd160x80/breakout_colourlcd160x80.cpp
index 42bc4d6c..2d387c75 100644
--- a/micropython/modules/breakout_colourlcd160x80/breakout_colourlcd160x80.cpp
+++ b/micropython/modules/breakout_colourlcd160x80/breakout_colourlcd160x80.cpp
@@ -120,7 +120,7 @@ mp_obj_t BreakoutColourLCD160x80_make_new(const mp_obj_type_t *type, size_t n_ar
 
         spi_inst_t *spi = (spi_id == 0) ? spi0 : spi1;
         self->breakout = new BreakoutColourLCD160x80((uint16_t *)bufinfo.buf, spi,
-            args[ARG_cs].u_int, args[ARG_dc].u_int, sck, mosi, BreakoutColourLCD160x80::PIN_UNUSED, args[ARG_bl].u_int);
+            args[ARG_cs].u_int, args[ARG_dc].u_int, sck, mosi, PIN_UNUSED, args[ARG_bl].u_int);
     }
 
     self->breakout->init();
diff --git a/micropython/modules/breakout_colourlcd240x240/breakout_colourlcd240x240.cpp b/micropython/modules/breakout_colourlcd240x240/breakout_colourlcd240x240.cpp
index 642d9638..79aa909f 100644
--- a/micropython/modules/breakout_colourlcd240x240/breakout_colourlcd240x240.cpp
+++ b/micropython/modules/breakout_colourlcd240x240/breakout_colourlcd240x240.cpp
@@ -120,7 +120,7 @@ mp_obj_t BreakoutColourLCD240x240_make_new(const mp_obj_type_t *type, size_t n_a
 
         spi_inst_t *spi = (spi_id == 0) ? spi0 : spi1;
         self->breakout = new BreakoutColourLCD240x240((uint16_t *)bufinfo.buf, spi,
-            args[ARG_cs].u_int, args[ARG_dc].u_int, sck, mosi, BreakoutColourLCD240x240::PIN_UNUSED, args[ARG_bl].u_int);
+            args[ARG_cs].u_int, args[ARG_dc].u_int, sck, mosi, PIN_UNUSED, args[ARG_bl].u_int);
     }
 
     self->breakout->init();
diff --git a/micropython/modules/breakout_dotmatrix/breakout_dotmatrix.cpp b/micropython/modules/breakout_dotmatrix/breakout_dotmatrix.cpp
index f8205c37..09de89c3 100644
--- a/micropython/modules/breakout_dotmatrix/breakout_dotmatrix.cpp
+++ b/micropython/modules/breakout_dotmatrix/breakout_dotmatrix.cpp
@@ -51,8 +51,8 @@ mp_obj_t BreakoutDotMatrix_make_new(const mp_obj_type_t *type, size_t n_args, si
     static const mp_arg_t allowed_args[] = {
         { MP_QSTR_i2c, MP_ARG_INT, {.u_int = -1} },
         { MP_QSTR_address, MP_ARG_INT, {.u_int = BreakoutDotMatrix::DEFAULT_I2C_ADDRESS} },
-        { MP_QSTR_sda, MP_ARG_INT, {.u_int = 20} },
-        { MP_QSTR_scl, MP_ARG_INT, {.u_int = 21} },
+        { MP_QSTR_sda, MP_ARG_INT, {.u_int = I2C_DEFAULT_SDA} },
+        { MP_QSTR_scl, MP_ARG_INT, {.u_int = I2C_DEFAULT_SCL} },
     };
 
     // Parse args.
diff --git a/micropython/modules/breakout_encoder/breakout_encoder.cpp b/micropython/modules/breakout_encoder/breakout_encoder.cpp
index 8d30b1bc..c111c3f6 100644
--- a/micropython/modules/breakout_encoder/breakout_encoder.cpp
+++ b/micropython/modules/breakout_encoder/breakout_encoder.cpp
@@ -54,9 +54,9 @@ mp_obj_t BreakoutEncoder_make_new(const mp_obj_type_t *type, size_t n_args, size
     static const mp_arg_t allowed_args[] = {
         { MP_QSTR_i2c, MP_ARG_INT, {.u_int = -1} },
         { MP_QSTR_address, MP_ARG_INT, {.u_int = BreakoutEncoder::DEFAULT_I2C_ADDRESS} },
-        { MP_QSTR_sda, MP_ARG_INT, {.u_int = 20} },
-        { MP_QSTR_scl, MP_ARG_INT, {.u_int = 21} },
-        { MP_QSTR_interrupt, MP_ARG_INT, {.u_int = BreakoutEncoder::PIN_UNUSED} },
+        { MP_QSTR_sda, MP_ARG_INT, {.u_int = I2C_DEFAULT_SDA} },
+        { MP_QSTR_scl, MP_ARG_INT, {.u_int = I2C_DEFAULT_SCL} },
+        { MP_QSTR_interrupt, MP_ARG_INT, {.u_int = PIN_UNUSED} },
     };
 
     // Parse args.
diff --git a/micropython/modules/breakout_ioexpander/breakout_ioexpander.cpp b/micropython/modules/breakout_ioexpander/breakout_ioexpander.cpp
index 272405be..5f84e350 100644
--- a/micropython/modules/breakout_ioexpander/breakout_ioexpander.cpp
+++ b/micropython/modules/breakout_ioexpander/breakout_ioexpander.cpp
@@ -54,9 +54,9 @@ mp_obj_t BreakoutIOExpander_make_new(const mp_obj_type_t *type, size_t n_args, s
     static const mp_arg_t allowed_args[] = {
         { MP_QSTR_i2c, MP_ARG_INT, {.u_int = -1} },
         { MP_QSTR_address, MP_ARG_INT, {.u_int = BreakoutIOExpander::DEFAULT_I2C_ADDRESS} },
-        { MP_QSTR_sda, MP_ARG_INT, {.u_int = 20} },
-        { MP_QSTR_scl, MP_ARG_INT, {.u_int = 21} },
-        { MP_QSTR_interrupt, MP_ARG_INT, {.u_int = BreakoutIOExpander::PIN_UNUSED} },
+        { MP_QSTR_sda, MP_ARG_INT, {.u_int = I2C_DEFAULT_SDA} },
+        { MP_QSTR_scl, MP_ARG_INT, {.u_int = I2C_DEFAULT_SCL} },
+        { MP_QSTR_interrupt, MP_ARG_INT, {.u_int = PIN_UNUSED} },
     };
 
     // Parse args.
diff --git a/micropython/modules/breakout_ltr559/breakout_ltr559.cpp b/micropython/modules/breakout_ltr559/breakout_ltr559.cpp
index 645df5a1..1c10e0e2 100644
--- a/micropython/modules/breakout_ltr559/breakout_ltr559.cpp
+++ b/micropython/modules/breakout_ltr559/breakout_ltr559.cpp
@@ -54,9 +54,9 @@ mp_obj_t BreakoutLTR559_make_new(const mp_obj_type_t *type, size_t n_args, size_
     static const mp_arg_t allowed_args[] = {
         { MP_QSTR_i2c, MP_ARG_INT, {.u_int = -1} },
         { MP_QSTR_address, MP_ARG_INT, {.u_int = BreakoutLTR559::DEFAULT_I2C_ADDRESS} },
-        { MP_QSTR_sda, MP_ARG_INT, {.u_int = 20} },
-        { MP_QSTR_scl, MP_ARG_INT, {.u_int = 21} },
-        { MP_QSTR_interrupt, MP_ARG_INT, {.u_int = BreakoutLTR559::PIN_UNUSED} },
+        { MP_QSTR_sda, MP_ARG_INT, {.u_int = I2C_DEFAULT_SDA} },
+        { MP_QSTR_scl, MP_ARG_INT, {.u_int = I2C_DEFAULT_SCL} },
+        { MP_QSTR_interrupt, MP_ARG_INT, {.u_int = -1} },
     };
 
     // Parse args.
diff --git a/micropython/modules/breakout_matrix11x7/breakout_matrix11x7.cpp b/micropython/modules/breakout_matrix11x7/breakout_matrix11x7.cpp
index 801f8bae..5952fcdf 100644
--- a/micropython/modules/breakout_matrix11x7/breakout_matrix11x7.cpp
+++ b/micropython/modules/breakout_matrix11x7/breakout_matrix11x7.cpp
@@ -51,8 +51,8 @@ mp_obj_t BreakoutMatrix11x7_make_new(const mp_obj_type_t *type, size_t n_args, s
     static const mp_arg_t allowed_args[] = {
         { MP_QSTR_i2c, MP_ARG_INT, {.u_int = -1} },
         { MP_QSTR_address, MP_ARG_INT, {.u_int = BreakoutMatrix11x7::DEFAULT_I2C_ADDRESS} },
-        { MP_QSTR_sda, MP_ARG_INT, {.u_int = 20} },
-        { MP_QSTR_scl, MP_ARG_INT, {.u_int = 21} },
+        { MP_QSTR_sda, MP_ARG_INT, {.u_int = I2C_DEFAULT_SDA} },
+        { MP_QSTR_scl, MP_ARG_INT, {.u_int = I2C_DEFAULT_SCL} },
     };
 
     // Parse args.
diff --git a/micropython/modules/breakout_mics6814/breakout_mics6814.cpp b/micropython/modules/breakout_mics6814/breakout_mics6814.cpp
index 5579c016..0bd565f3 100644
--- a/micropython/modules/breakout_mics6814/breakout_mics6814.cpp
+++ b/micropython/modules/breakout_mics6814/breakout_mics6814.cpp
@@ -54,9 +54,9 @@ mp_obj_t BreakoutMICS6814_make_new(const mp_obj_type_t *type, size_t n_args, siz
         static const mp_arg_t allowed_args[] = {
         { MP_QSTR_i2c, MP_ARG_INT, {.u_int = -1} },
         { MP_QSTR_address, MP_ARG_INT, {.u_int = BreakoutMICS6814::DEFAULT_I2C_ADDRESS} },
-        { MP_QSTR_sda, MP_ARG_INT, {.u_int = 20} },
-        { MP_QSTR_scl, MP_ARG_INT, {.u_int = 21} },
-        { MP_QSTR_interrupt, MP_ARG_INT, {.u_int = BreakoutMICS6814::PIN_UNUSED} },
+        { MP_QSTR_sda, MP_ARG_INT, {.u_int = I2C_DEFAULT_SDA} },
+        { MP_QSTR_scl, MP_ARG_INT, {.u_int = I2C_DEFAULT_SCL} },
+        { MP_QSTR_interrupt, MP_ARG_INT, {.u_int = PIN_UNUSED} },
     };
 
     // Parse args.
diff --git a/micropython/modules/breakout_msa301/breakout_msa301.cpp b/micropython/modules/breakout_msa301/breakout_msa301.cpp
index a59628ef..bd1cea90 100644
--- a/micropython/modules/breakout_msa301/breakout_msa301.cpp
+++ b/micropython/modules/breakout_msa301/breakout_msa301.cpp
@@ -47,9 +47,9 @@ mp_obj_t BreakoutMSA301_make_new(const mp_obj_type_t *type, size_t n_args, size_
     enum { ARG_i2c, ARG_sda, ARG_scl, ARG_interrupt };
     static const mp_arg_t allowed_args[] = {
         { MP_QSTR_i2c, MP_ARG_INT, {.u_int = -1} },
-        { MP_QSTR_sda, MP_ARG_INT, {.u_int = 20} },
-        { MP_QSTR_scl, MP_ARG_INT, {.u_int = 21} },
-        { MP_QSTR_interrupt, MP_ARG_INT, {.u_int = BreakoutMSA301::PIN_UNUSED} },
+        { MP_QSTR_sda, MP_ARG_INT, {.u_int = I2C_DEFAULT_SDA} },
+        { MP_QSTR_scl, MP_ARG_INT, {.u_int = I2C_DEFAULT_SCL} },
+        { MP_QSTR_interrupt, MP_ARG_INT, {.u_int = PIN_UNUSED} },
     };
 
     // Parse args.
diff --git a/micropython/modules/breakout_potentiometer/breakout_potentiometer.cpp b/micropython/modules/breakout_potentiometer/breakout_potentiometer.cpp
index 2812a161..47aa7127 100644
--- a/micropython/modules/breakout_potentiometer/breakout_potentiometer.cpp
+++ b/micropython/modules/breakout_potentiometer/breakout_potentiometer.cpp
@@ -54,9 +54,9 @@ mp_obj_t BreakoutPotentiometer_make_new(const mp_obj_type_t *type, size_t n_args
     static const mp_arg_t allowed_args[] = {
         { MP_QSTR_i2c, MP_ARG_INT, {.u_int = -1} },
         { MP_QSTR_address, MP_ARG_INT, {.u_int = BreakoutPotentiometer::DEFAULT_I2C_ADDRESS} },
-        { MP_QSTR_sda, MP_ARG_INT, {.u_int = 20} },
-        { MP_QSTR_scl, MP_ARG_INT, {.u_int = 21} },
-        { MP_QSTR_interrupt, MP_ARG_INT, {.u_int = BreakoutPotentiometer::PIN_UNUSED} },
+        { MP_QSTR_sda, MP_ARG_INT, {.u_int = I2C_DEFAULT_SDA} },
+        { MP_QSTR_scl, MP_ARG_INT, {.u_int = I2C_DEFAULT_SCL} },
+        { MP_QSTR_interrupt, MP_ARG_INT, {.u_int = PIN_UNUSED} },
     };
 
     // Parse args.
diff --git a/micropython/modules/breakout_rgbmatrix5x5/breakout_rgbmatrix5x5.cpp b/micropython/modules/breakout_rgbmatrix5x5/breakout_rgbmatrix5x5.cpp
index 3057e507..3e4859a9 100644
--- a/micropython/modules/breakout_rgbmatrix5x5/breakout_rgbmatrix5x5.cpp
+++ b/micropython/modules/breakout_rgbmatrix5x5/breakout_rgbmatrix5x5.cpp
@@ -51,8 +51,8 @@ mp_obj_t BreakoutRGBMatrix5x5_make_new(const mp_obj_type_t *type, size_t n_args,
     static const mp_arg_t allowed_args[] = {
         { MP_QSTR_i2c, MP_ARG_INT, {.u_int = -1} },
         { MP_QSTR_address, MP_ARG_INT, {.u_int = BreakoutRGBMatrix5x5::DEFAULT_I2C_ADDRESS} },
-        { MP_QSTR_sda, MP_ARG_INT, {.u_int = 20} },
-        { MP_QSTR_scl, MP_ARG_INT, {.u_int = 21} },
+        { MP_QSTR_sda, MP_ARG_INT, {.u_int = I2C_DEFAULT_SDA} },
+        { MP_QSTR_scl, MP_ARG_INT, {.u_int = I2C_DEFAULT_SCL} },
     };
 
     // Parse args.
diff --git a/micropython/modules/breakout_roundlcd/breakout_roundlcd.cpp b/micropython/modules/breakout_roundlcd/breakout_roundlcd.cpp
index 901aa9dd..3f970b37 100644
--- a/micropython/modules/breakout_roundlcd/breakout_roundlcd.cpp
+++ b/micropython/modules/breakout_roundlcd/breakout_roundlcd.cpp
@@ -120,7 +120,7 @@ mp_obj_t BreakoutRoundLCD_make_new(const mp_obj_type_t *type, size_t n_args, siz
 
         spi_inst_t *spi = (spi_id == 0) ? spi0 : spi1;
         self->breakout = new BreakoutRoundLCD((uint16_t *)bufinfo.buf, spi,
-            args[ARG_cs].u_int, args[ARG_dc].u_int, sck, mosi, BreakoutRoundLCD::PIN_UNUSED, args[ARG_bl].u_int);
+            args[ARG_cs].u_int, args[ARG_dc].u_int, sck, mosi, PIN_UNUSED, args[ARG_bl].u_int);
     }
 
     self->breakout->init();
diff --git a/micropython/modules/breakout_rtc/breakout_rtc.cpp b/micropython/modules/breakout_rtc/breakout_rtc.cpp
index d36df64d..7ab6793d 100644
--- a/micropython/modules/breakout_rtc/breakout_rtc.cpp
+++ b/micropython/modules/breakout_rtc/breakout_rtc.cpp
@@ -50,9 +50,9 @@ mp_obj_t BreakoutRTC_make_new(const mp_obj_type_t *type, size_t n_args, size_t n
     enum { ARG_i2c, ARG_sda, ARG_scl, ARG_interrupt };
     static const mp_arg_t allowed_args[] = {
         { MP_QSTR_i2c, MP_ARG_INT, {.u_int = -1} },
-        { MP_QSTR_sda, MP_ARG_INT, {.u_int = 20} },
-        { MP_QSTR_scl, MP_ARG_INT, {.u_int = 21} },
-        { MP_QSTR_interrupt, MP_ARG_INT, {.u_int = BreakoutRTC::PIN_UNUSED} },
+        { MP_QSTR_sda, MP_ARG_INT, {.u_int = I2C_DEFAULT_SDA} },
+        { MP_QSTR_scl, MP_ARG_INT, {.u_int = I2C_DEFAULT_SCL} },
+        { MP_QSTR_interrupt, MP_ARG_INT, {.u_int = PIN_UNUSED} },
     };
 
     // Parse args.
diff --git a/micropython/modules/breakout_sgp30/breakout_sgp30.cpp b/micropython/modules/breakout_sgp30/breakout_sgp30.cpp
index 7812b4a1..10c6a42d 100644
--- a/micropython/modules/breakout_sgp30/breakout_sgp30.cpp
+++ b/micropython/modules/breakout_sgp30/breakout_sgp30.cpp
@@ -44,8 +44,8 @@ mp_obj_t BreakoutSGP30_make_new(const mp_obj_type_t *type, size_t n_args, size_t
     enum { ARG_i2c, ARG_sda, ARG_scl };
     static const mp_arg_t allowed_args[] = {
         { MP_QSTR_i2c, MP_ARG_INT, {.u_int = -1} },
-        { MP_QSTR_sda, MP_ARG_INT, {.u_int = 20} },
-        { MP_QSTR_scl, MP_ARG_INT, {.u_int = 21} },
+        { MP_QSTR_sda, MP_ARG_INT, {.u_int = I2C_DEFAULT_SDA} },
+        { MP_QSTR_scl, MP_ARG_INT, {.u_int = I2C_DEFAULT_SCL} },
     };
 
     // Parse args.
diff --git a/micropython/modules/breakout_trackball/breakout_trackball.cpp b/micropython/modules/breakout_trackball/breakout_trackball.cpp
index 81b23f3c..660c9630 100644
--- a/micropython/modules/breakout_trackball/breakout_trackball.cpp
+++ b/micropython/modules/breakout_trackball/breakout_trackball.cpp
@@ -54,9 +54,9 @@ mp_obj_t BreakoutTrackball_make_new(const mp_obj_type_t *type, size_t n_args, si
     static const mp_arg_t allowed_args[] = {
         { MP_QSTR_i2c, MP_ARG_INT, {.u_int = -1} },
         { MP_QSTR_address, MP_ARG_INT, {.u_int = BreakoutTrackball::DEFAULT_I2C_ADDRESS} },
-        { MP_QSTR_sda, MP_ARG_INT, {.u_int = 20} },
-        { MP_QSTR_scl, MP_ARG_INT, {.u_int = 21} },
-        { MP_QSTR_interrupt, MP_ARG_INT, {.u_int = BreakoutTrackball::PIN_UNUSED} },
+        { MP_QSTR_sda, MP_ARG_INT, {.u_int = I2C_DEFAULT_SDA} },
+        { MP_QSTR_scl, MP_ARG_INT, {.u_int = I2C_DEFAULT_SCL} },
+        { MP_QSTR_interrupt, MP_ARG_INT, {.u_int = PIN_UNUSED} },
     };
 
     // Parse args.