diff --git a/ports/stm32/accel.c b/ports/stm32/accel.c
index 0d7708c09..73ddcf8cf 100644
--- a/ports/stm32/accel.c
+++ b/ports/stm32/accel.c
@@ -46,6 +46,8 @@
 ///
 /// Raw values are between -32 and 31.
 
+#define I2C_TIMEOUT_MS (50)
+
 #define MMA_ADDR (76)
 #define MMA_REG_X (0)
 #define MMA_REG_Y (1)
@@ -62,7 +64,7 @@ void accel_init(void) {
 
 STATIC void accel_start(void) {
     // start the I2C bus in master mode
-    i2c_init(I2C1, MICROPY_HW_I2C1_SCL, MICROPY_HW_I2C1_SDA, 400000);
+    i2c_init(I2C1, MICROPY_HW_I2C1_SCL, MICROPY_HW_I2C1_SDA, 400000, I2C_TIMEOUT_MS);
 
     // turn off AVDD, wait 30ms, turn on AVDD, wait 30ms again
     mp_hal_pin_low(MICROPY_HW_MMA_AVDD_PIN); // turn off
diff --git a/ports/stm32/i2c.c b/ports/stm32/i2c.c
index 109b9418f..06e26d912 100644
--- a/ports/stm32/i2c.c
+++ b/ports/stm32/i2c.c
@@ -30,11 +30,11 @@
 
 #if MICROPY_HW_ENABLE_HW_I2C
 
-#define I2C_POLL_TIMEOUT_MS (50)
-
 #if defined(STM32F4)
 
-int i2c_init(i2c_t *i2c, mp_hal_pin_obj_t scl, mp_hal_pin_obj_t sda, uint32_t freq) {
+STATIC uint16_t i2c_timeout_ms[MICROPY_HW_MAX_I2C];
+
+int i2c_init(i2c_t *i2c, mp_hal_pin_obj_t scl, mp_hal_pin_obj_t sda, uint32_t freq, uint16_t timeout_ms) {
     uint32_t i2c_id = ((uint32_t)i2c - I2C1_BASE) / (I2C2_BASE - I2C1_BASE);
 
     // Init pins
@@ -45,6 +45,9 @@ int i2c_init(i2c_t *i2c, mp_hal_pin_obj_t scl, mp_hal_pin_obj_t sda, uint32_t fr
         return -MP_EPERM;
     }
 
+    // Save timeout value
+    i2c_timeout_ms[i2c_id] = timeout_ms;
+
     // Force reset I2C peripheral
     RCC->APB1RSTR |= RCC_APB1RSTR_I2C1RST << i2c_id;
     RCC->APB1RSTR &= ~(RCC_APB1RSTR_I2C1RST << i2c_id);
@@ -88,9 +91,10 @@ int i2c_init(i2c_t *i2c, mp_hal_pin_obj_t scl, mp_hal_pin_obj_t sda, uint32_t fr
 }
 
 STATIC int i2c_wait_sr1_set(i2c_t *i2c, uint32_t mask) {
+    uint32_t i2c_id = ((uint32_t)i2c - I2C1_BASE) / (I2C2_BASE - I2C1_BASE);
     uint32_t t0 = HAL_GetTick();
     while (!(i2c->SR1 & mask)) {
-        if (HAL_GetTick() - t0 >= I2C_POLL_TIMEOUT_MS) {
+        if (HAL_GetTick() - t0 >= i2c_timeout_ms[i2c_id]) {
             i2c->CR1 &= ~I2C_CR1_PE;
             return -MP_ETIMEDOUT;
         }
@@ -99,9 +103,10 @@ STATIC int i2c_wait_sr1_set(i2c_t *i2c, uint32_t mask) {
 }
 
 STATIC int i2c_wait_stop(i2c_t *i2c) {
+    uint32_t i2c_id = ((uint32_t)i2c - I2C1_BASE) / (I2C2_BASE - I2C1_BASE);
     uint32_t t0 = HAL_GetTick();
     while (i2c->CR1 & I2C_CR1_STOP) {
-        if (HAL_GetTick() - t0 >= I2C_POLL_TIMEOUT_MS) {
+        if (HAL_GetTick() - t0 >= i2c_timeout_ms[i2c_id]) {
             i2c->CR1 &= ~I2C_CR1_PE;
             return -MP_ETIMEDOUT;
         }
@@ -264,7 +269,9 @@ int i2c_write(i2c_t *i2c, const uint8_t *src, size_t len, size_t next_len) {
 
 #elif defined(STM32F0) || defined(STM32F7)
 
-int i2c_init(i2c_t *i2c, mp_hal_pin_obj_t scl, mp_hal_pin_obj_t sda, uint32_t freq) {
+STATIC uint16_t i2c_timeout_ms[MICROPY_HW_MAX_I2C];
+
+int i2c_init(i2c_t *i2c, mp_hal_pin_obj_t scl, mp_hal_pin_obj_t sda, uint32_t freq, uint16_t timeout_ms) {
     uint32_t i2c_id = ((uint32_t)i2c - I2C1_BASE) / (I2C2_BASE - I2C1_BASE);
 
     // Init pins
@@ -275,6 +282,9 @@ int i2c_init(i2c_t *i2c, mp_hal_pin_obj_t scl, mp_hal_pin_obj_t sda, uint32_t fr
         return -MP_EPERM;
     }
 
+    // Save timeout value
+    i2c_timeout_ms[i2c_id] = timeout_ms;
+
     // Enable I2C peripheral clock
     RCC->APB1ENR |= RCC_APB1ENR_I2C1EN << i2c_id;
     volatile uint32_t tmp = RCC->APB1ENR; // delay after RCC clock enable
@@ -303,9 +313,10 @@ int i2c_init(i2c_t *i2c, mp_hal_pin_obj_t scl, mp_hal_pin_obj_t sda, uint32_t fr
 }
 
 STATIC int i2c_wait_cr2_clear(i2c_t *i2c, uint32_t mask) {
+    uint32_t i2c_id = ((uint32_t)i2c - I2C1_BASE) / (I2C2_BASE - I2C1_BASE);
     uint32_t t0 = HAL_GetTick();
     while (i2c->CR2 & mask) {
-        if (HAL_GetTick() - t0 >= I2C_POLL_TIMEOUT_MS) {
+        if (HAL_GetTick() - t0 >= i2c_timeout_ms[i2c_id]) {
             i2c->CR1 &= ~I2C_CR1_PE;
             return -MP_ETIMEDOUT;
         }
@@ -314,9 +325,10 @@ STATIC int i2c_wait_cr2_clear(i2c_t *i2c, uint32_t mask) {
 }
 
 STATIC int i2c_wait_isr_set(i2c_t *i2c, uint32_t mask) {
+    uint32_t i2c_id = ((uint32_t)i2c - I2C1_BASE) / (I2C2_BASE - I2C1_BASE);
     uint32_t t0 = HAL_GetTick();
     while (!(i2c->ISR & mask)) {
-        if (HAL_GetTick() - t0 >= I2C_POLL_TIMEOUT_MS) {
+        if (HAL_GetTick() - t0 >= i2c_timeout_ms[i2c_id]) {
             i2c->CR1 &= ~I2C_CR1_PE;
             return -MP_ETIMEDOUT;
         }
diff --git a/ports/stm32/i2c.h b/ports/stm32/i2c.h
index 5599f4123..4846f1cf3 100644
--- a/ports/stm32/i2c.h
+++ b/ports/stm32/i2c.h
@@ -55,7 +55,7 @@ void i2c_er_irq_handler(mp_uint_t i2c_id);
 
 typedef I2C_TypeDef i2c_t;
 
-int i2c_init(i2c_t *i2c, mp_hal_pin_obj_t scl, mp_hal_pin_obj_t sda, uint32_t freq);
+int i2c_init(i2c_t *i2c, mp_hal_pin_obj_t scl, mp_hal_pin_obj_t sda, uint32_t freq, uint16_t timeout);
 int i2c_start_addr(i2c_t *i2c, int rd_wrn, uint16_t addr, size_t len, bool stop);
 int i2c_read(i2c_t *i2c, uint8_t *dest, size_t len, size_t next_len);
 int i2c_write(i2c_t *i2c, const uint8_t *src, size_t len, size_t next_len);
diff --git a/ports/stm32/machine_i2c.c b/ports/stm32/machine_i2c.c
index 037401d86..5acf9c7d6 100644
--- a/ports/stm32/machine_i2c.c
+++ b/ports/stm32/machine_i2c.c
@@ -37,6 +37,8 @@
 
 STATIC const mp_obj_type_t machine_hard_i2c_type;
 
+#define I2C_POLL_DEFAULT_TIMEOUT_US (50000) // 50ms
+
 #if defined(STM32F0) || defined(STM32F4) || defined(STM32F7)
 
 typedef struct _machine_hard_i2c_obj_t {
@@ -104,9 +106,9 @@ STATIC void machine_hard_i2c_print(const mp_print_t *print, mp_obj_t self_in, mp
     #endif
 }
 
-void machine_hard_i2c_init(machine_hard_i2c_obj_t *self, uint32_t freq, uint32_t timeout) {
-    (void)timeout;
-    i2c_init(self->i2c, self->scl, self->sda, freq);
+void machine_hard_i2c_init(machine_hard_i2c_obj_t *self, uint32_t freq, uint32_t timeout_us) {
+    uint32_t timeout_ms = (timeout_us + 999) / 1000;
+    i2c_init(self->i2c, self->scl, self->sda, freq, timeout_ms);
 }
 
 int machine_hard_i2c_transfer(mp_obj_base_t *self_in, uint16_t addr, size_t n, mp_machine_i2c_buf_t *bufs, unsigned int flags) {
@@ -147,22 +149,22 @@ typedef mp_machine_soft_i2c_obj_t machine_hard_i2c_obj_t;
 
 STATIC machine_hard_i2c_obj_t machine_hard_i2c_obj[] = {
     #if defined(MICROPY_HW_I2C1_SCL)
-    {{&machine_hard_i2c_type}, 1, 500, MICROPY_HW_I2C1_SCL, MICROPY_HW_I2C1_SDA},
+    {{&machine_hard_i2c_type}, 1, I2C_POLL_DEFAULT_TIMEOUT_US, MICROPY_HW_I2C1_SCL, MICROPY_HW_I2C1_SDA},
     #else
     {{NULL}, 0, 0, NULL, NULL},
     #endif
     #if defined(MICROPY_HW_I2C2_SCL)
-    {{&machine_hard_i2c_type}, 1, 500, MICROPY_HW_I2C2_SCL, MICROPY_HW_I2C2_SDA},
+    {{&machine_hard_i2c_type}, 1, I2C_POLL_DEFAULT_TIMEOUT_US, MICROPY_HW_I2C2_SCL, MICROPY_HW_I2C2_SDA},
     #else
     {{NULL}, 0, 0, NULL, NULL},
     #endif
     #if defined(MICROPY_HW_I2C3_SCL)
-    {{&machine_hard_i2c_type}, 1, 500, MICROPY_HW_I2C3_SCL, MICROPY_HW_I2C3_SDA},
+    {{&machine_hard_i2c_type}, 1, I2C_POLL_DEFAULT_TIMEOUT_US, MICROPY_HW_I2C3_SCL, MICROPY_HW_I2C3_SDA},
     #else
     {{NULL}, 0, 0, NULL, NULL},
     #endif
     #if defined(MICROPY_HW_I2C4_SCL)
-    {{&machine_hard_i2c_type}, 1, 500, MICROPY_HW_I2C4_SCL, MICROPY_HW_I2C4_SDA},
+    {{&machine_hard_i2c_type}, 1, I2C_POLL_DEFAULT_TIMEOUT_US, MICROPY_HW_I2C4_SCL, MICROPY_HW_I2C4_SDA},
     #else
     {{NULL}, 0, 0, NULL, NULL},
     #endif
@@ -209,7 +211,7 @@ mp_obj_t machine_hard_i2c_make_new(const mp_obj_type_t *type, size_t n_args, siz
         { MP_QSTR_scl, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
         { MP_QSTR_sda, MP_ARG_KW_ONLY | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
         { MP_QSTR_freq, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 400000} },
-        { MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 1000} },
+        { MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = I2C_POLL_DEFAULT_TIMEOUT_US} },
     };
     mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
     mp_arg_parse_all_kw_array(n_args, n_kw, all_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
diff --git a/ports/stm32/mpconfigboard_common.h b/ports/stm32/mpconfigboard_common.h
index 4348f50bd..f3a3d48e7 100644
--- a/ports/stm32/mpconfigboard_common.h
+++ b/ports/stm32/mpconfigboard_common.h
@@ -138,6 +138,7 @@
 
 #define MP_HAL_UNIQUE_ID_ADDRESS (0x1ffff7ac)
 #define PYB_EXTI_NUM_VECTORS (23)
+#define MICROPY_HW_MAX_I2C (2)
 #define MICROPY_HW_MAX_TIMER (17)
 #define MICROPY_HW_MAX_UART (8)
 
@@ -146,6 +147,7 @@
 
 #define MP_HAL_UNIQUE_ID_ADDRESS (0x1fff7a10)
 #define PYB_EXTI_NUM_VECTORS (23)
+#define MICROPY_HW_MAX_I2C (3)
 #define MICROPY_HW_MAX_TIMER (14)
 #if defined(UART10)
 #define MICROPY_HW_MAX_UART (10)
@@ -169,6 +171,7 @@
 #endif
 
 #define PYB_EXTI_NUM_VECTORS (24)
+#define MICROPY_HW_MAX_I2C (4)
 #define MICROPY_HW_MAX_TIMER (17)
 #define MICROPY_HW_MAX_UART (8)