diff --git a/stmhal/boards/NETDUINO_PLUS_2/mpconfigboard.h b/stmhal/boards/NETDUINO_PLUS_2/mpconfigboard.h
index a01d37aea84ab999f1ad74dec7866f76200a2a46..a626f4534bcb78e7d65915b351290f6eaa758628 100644
--- a/stmhal/boards/NETDUINO_PLUS_2/mpconfigboard.h
+++ b/stmhal/boards/NETDUINO_PLUS_2/mpconfigboard.h
@@ -17,6 +17,8 @@
 #define MICROPY_HW_ENABLE_TIMER     (1)
 #define MICROPY_HW_ENABLE_SERVO     (1)
 #define MICROPY_HW_ENABLE_DAC       (0)
+#define MICROPU_HW_ENABLE_I2C1      (0)
+#define MICROPU_HW_ENABLE_SPI1      (0)
 
 // USRSW is pulled low. Pressing the button makes the input go high.
 #define MICROPY_HW_USRSW_PIN        (pin_B11)
diff --git a/stmhal/i2c.c b/stmhal/i2c.c
index 8a8dd7dc2d6b6227d6096ab074e58779a56bcc48..4d2710d8e5d0f229fb575df7d9d385727b60d6d2 100644
--- a/stmhal/i2c.c
+++ b/stmhal/i2c.c
@@ -13,6 +13,10 @@
 #include "genhdr/pins.h"
 #include "i2c.h"
 
+#if !defined(MICROPU_HW_ENABLE_I2C1)
+#define MICROPY_HW_ENABLE_I2C1      (1)
+#endif
+
 I2C_HandleTypeDef I2CHandle1 = {.Instance = NULL};
 I2C_HandleTypeDef I2CHandle2 = {.Instance = NULL};
 
@@ -32,6 +36,7 @@ void i2c_init(I2C_HandleTypeDef *i2c) {
     GPIO_InitStructure.Pull = GPIO_NOPULL; // have external pull-up resistors on both lines
 
     const pin_obj_t *pins[2];
+#if MICROPY_HW_ENABLE_I2C1
     if (i2c == &I2CHandle1) {
         // X-skin: X9=PB6=SCL, X10=PB7=SDA
         pins[0] = &pin_B6;
@@ -39,7 +44,9 @@ void i2c_init(I2C_HandleTypeDef *i2c) {
         GPIO_InitStructure.Alternate = GPIO_AF4_I2C1;
         // enable the I2C clock
         __I2C1_CLK_ENABLE();
-    } else {
+    } else
+#endif
+    if (i2c == &I2CHandle2) {
         // Y-skin: Y9=PB10=SCL, Y10=PB11=SDA
         pins[0] = &pin_B10;
         pins[1] = &pin_B11;
@@ -54,13 +61,6 @@ void i2c_init(I2C_HandleTypeDef *i2c) {
         HAL_GPIO_Init(pins[i]->gpio, &GPIO_InitStructure);
     }
 
-    // enable the I2C clock
-    if (i2c == &I2CHandle1) {
-        __I2C1_CLK_ENABLE();
-    } else {
-        __I2C2_CLK_ENABLE();
-    }
-
     // init the I2C device
     i2c->Init.AddressingMode  = I2C_ADDRESSINGMODE_7BIT;
     i2c->Init.ClockSpeed      = 400000;
@@ -88,7 +88,10 @@ typedef struct _pyb_i2c_obj_t {
     I2C_HandleTypeDef *i2c;
 } pyb_i2c_obj_t;
 
-STATIC const pyb_i2c_obj_t pyb_i2c_obj[PYB_NUM_I2C] = {{{&pyb_i2c_type}, &I2CHandle1}, {{&pyb_i2c_type}, &I2CHandle2}};
+STATIC const pyb_i2c_obj_t pyb_i2c_obj[PYB_NUM_I2C] = {
+    {{&pyb_i2c_type}, &I2CHandle1},
+    {{&pyb_i2c_type}, &I2CHandle2}
+};
 
 STATIC mp_obj_t pyb_i2c_make_new(mp_obj_t type_in, uint n_args, uint n_kw, const mp_obj_t *args) {
     // check arguments
diff --git a/stmhal/spi.c b/stmhal/spi.c
index 9e48bc899e09ee4d60c17026b3d97aacf58bc950..5e5049bef96edf1a0ba79757bb14a9b89bce4e86 100644
--- a/stmhal/spi.c
+++ b/stmhal/spi.c
@@ -13,11 +13,13 @@
 #include "genhdr/pins.h"
 #include "spi.h"
 
+#if !defined(MICROPU_HW_ENABLE_SPI1)
+#define MICROPY_HW_ENABLE_SPI1  (1)
+#endif
+
 SPI_HandleTypeDef SPIHandle1 = {.Instance = NULL};
 SPI_HandleTypeDef SPIHandle2 = {.Instance = NULL};
-#if MICROPY_HW_ENABLE_SPI3
 SPI_HandleTypeDef SPIHandle3 = {.Instance = NULL};
-#endif
 
 void spi_init0(void) {
     // reset the SPI handles
@@ -25,10 +27,8 @@ void spi_init0(void) {
     SPIHandle1.Instance = SPI1;
     memset(&SPIHandle2, 0, sizeof(SPI_HandleTypeDef));
     SPIHandle2.Instance = SPI2;
-#if MICROPY_HW_ENABLE_SPI3
     memset(&SPIHandle3, 0, sizeof(SPI_HandleTypeDef));
     SPIHandle3.Instance = SPI3;
-#endif
 }
 
 // TODO allow to take a list of pins to use
@@ -40,6 +40,7 @@ void spi_init(SPI_HandleTypeDef *spi) {
     GPIO_InitStructure.Pull = GPIO_PULLUP; // ST examples use PULLUP
 
     const pin_obj_t *pins[4];
+#if MICROPY_HW_ENABLE_SPI1
     if (spi->Instance == SPI1) {
         // X-skin: X5=PA4=SPI1_NSS, X6=PA5=SPI1_SCK, X7=PA6=SPI1_MISO, X8=PA7=SPI1_MOSI
         pins[0] = &pin_A4;
@@ -47,25 +48,28 @@ void spi_init(SPI_HandleTypeDef *spi) {
         pins[2] = &pin_A6;
         pins[3] = &pin_A7;
         GPIO_InitStructure.Alternate = GPIO_AF5_SPI1;
-    } else if (spi->Instance == SPI2) {
+    } else
+#endif
+    if (spi->Instance == SPI2) {
         // Y-skin: Y5=PB12=SPI2_NSS, Y6=PB13=SPI2_SCK, Y7=PB14=SPI2_MISO, Y8=PB15=SPI2_MOSI
         pins[0] = &pin_B12;
         pins[1] = &pin_B13;
         pins[2] = &pin_B14;
         pins[3] = &pin_B15;
         GPIO_InitStructure.Alternate = GPIO_AF5_SPI2;
+    } else
 #if MICROPY_HW_ENABLE_SPI3
-    } else if (spi->Instance == SPI3) {
+    if (spi->Instance == SPI3) {
         pins[0] = &pin_A4;
         pins[1] = &pin_B3;
         pins[2] = &pin_B4;
         pins[3] = &pin_B5;
         GPIO_InitStructure.Alternate = GPIO_AF6_SPI3;
+    } else
 #endif
-    } else {
+    {
         // SPI does not exist for this board
-        printf("HardwareError: invalid SPI\n");
-        return;
+        nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, "SPI bus does not exist"));
     }
 
     for (uint i = 0; i < 4; i++) {
@@ -78,10 +82,8 @@ void spi_init(SPI_HandleTypeDef *spi) {
         __SPI1_CLK_ENABLE();
     } else if (spi->Instance == SPI2) {
         __SPI2_CLK_ENABLE();
-#if MICROPY_HW_ENABLE_SPI3
-    } else {
+    } else if (spi->Instance == SPI3) {
         __SPI3_CLK_ENABLE();
-#endif
     }
 
     // init the I2C device
@@ -100,24 +102,25 @@ void spi_deinit(SPI_HandleTypeDef *spi) {
         __SPI1_CLK_DISABLE();
     } else if (spi->Instance == SPI2) {
         __SPI2_CLK_DISABLE();
-#if MICROPY_HW_ENABLE_SPI3
-    } else {
+    } else if (spi->Instance == SPI3) {
         __SPI3_CLK_DISABLE();
-#endif
     }
 }
 
 /******************************************************************************/
 /* Micro Python bindings                                                      */
 
-#define PYB_SPI_NUM (2)
+#define PYB_NUM_SPI (2)
 
 typedef struct _pyb_spi_obj_t {
     mp_obj_base_t base;
     SPI_HandleTypeDef *spi;
 } pyb_spi_obj_t;
 
-STATIC const pyb_spi_obj_t pyb_spi_obj[PYB_SPI_NUM] = {{{&pyb_spi_type}, &SPIHandle1}, {{&pyb_spi_type}, &SPIHandle2}};
+STATIC const pyb_spi_obj_t pyb_spi_obj[PYB_NUM_SPI] = {
+    {{&pyb_spi_type}, &SPIHandle1},
+    {{&pyb_spi_type}, &SPIHandle2}
+};
 
 STATIC void pyb_spi_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
     pyb_spi_obj_t *self = self_in;
@@ -220,7 +223,7 @@ STATIC mp_obj_t pyb_spi_make_new(mp_obj_t type_in, uint n_args, uint n_kw, const
     machine_int_t spi_id = mp_obj_get_int(args[0]) - 1;
 
     // check SPI number
-    if (!(0 <= spi_id && spi_id < PYB_SPI_NUM)) {
+    if (!(0 <= spi_id && spi_id < PYB_NUM_SPI)) {
         nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "SPI bus %d does not exist", spi_id + 1));
     }