twi-fixes.diff

diff --git a/ports/nrf/bluetooth_conf.h b/ports/nrf/bluetooth_conf.h
index 6a3cbdc83..9e649c940 100644
--- a/ports/nrf/bluetooth_conf.h
+++ b/ports/nrf/bluetooth_conf.h
@@ -6,7 +6,7 @@
 #if (BLUETOOTH_SD == 110)
 
 #define MICROPY_PY_BLE                  (1)
-#define MICROPY_PY_BLE_NUS              (0)
+#define MICROPY_PY_BLE_NUS              (1)
 #define BLUETOOTH_WEBBLUETOOTH_REPL     (0)
 #define MICROPY_PY_UBLUEPY              (1)
 #define MICROPY_PY_UBLUEPY_PERIPHERAL   (1)
diff --git a/ports/nrf/hal/hal_twi.c b/ports/nrf/hal/hal_twi.c
index 65d729c94..01f78d18d 100644
--- a/ports/nrf/hal/hal_twi.c
+++ b/ports/nrf/hal/hal_twi.c
@@ -37,6 +37,22 @@ static const uint32_t hal_twi_frequency_lookup[] = {
 
 void hal_twi_master_init(NRF_TWI_Type * p_instance, hal_twi_init_t const * p_twi_init) {
 
+    // Configure pins: direction = input, drive strength = S0D1
+    // TODO: deconfigure at deinit
+    GPIO_BASE(p_twi_init->scl_pin->port)->PIN_CNF[p_twi_init->scl_pin->pin] =
+            (GPIO_PIN_CNF_DIR_Input << GPIO_PIN_CNF_DIR_Pos)
+          | (GPIO_PIN_CNF_INPUT_Connect << GPIO_PIN_CNF_INPUT_Pos)
+          | (GPIO_PIN_CNF_PULL_Pullup << GPIO_PIN_CNF_PULL_Pos)
+          | (GPIO_PIN_CNF_DRIVE_S0D1 << GPIO_PIN_CNF_DRIVE_Pos)
+          | (GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos);
+
+    GPIO_BASE(p_twi_init->sda_pin->port)->PIN_CNF[p_twi_init->sda_pin->pin] =
+            (GPIO_PIN_CNF_DIR_Input << GPIO_PIN_CNF_DIR_Pos)
+          | (GPIO_PIN_CNF_INPUT_Connect << GPIO_PIN_CNF_INPUT_Pos)
+          | (GPIO_PIN_CNF_PULL_Pullup << GPIO_PIN_CNF_PULL_Pos)
+          | (GPIO_PIN_CNF_DRIVE_S0D1 << GPIO_PIN_CNF_DRIVE_Pos)
+          | (GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos);
+
 #if NRF52840_XXAA
     p_instance->PSEL.SCL  = p_twi_init->scl_pin->pin;
     p_instance->PSEL.SDA  = p_twi_init->sda_pin->pin;
@@ -51,32 +67,45 @@ void hal_twi_master_init(NRF_TWI_Type * p_instance, hal_twi_init_t const * p_twi
     p_instance->ENABLE    = (TWI_ENABLE_ENABLE_Enabled << TWI_ENABLE_ENABLE_Pos);
 }
 #include <stdio.h>
-void hal_twi_master_tx(NRF_TWI_Type  * p_instance,
+uint32_t hal_twi_master_tx(NRF_TWI_Type  * p_instance,
                        uint8_t         addr,
-                       uint16_t        transfer_size,
+                       size_t          transfer_size,
                        const uint8_t * tx_data,
                        bool            stop) {
+    return 1;
 
-    uint16_t number_of_txd_bytes = 0;
+    if (transfer_size == 0) {
+        return 0;
+    }
 
     p_instance->ADDRESS = addr;
 
     p_instance->EVENTS_TXDSENT = 0;
 
-    p_instance->TXD            = tx_data[number_of_txd_bytes];
+    p_instance->TXD            = tx_data[0];
     p_instance->TASKS_STARTTX  = 1;
 
+    size_t number_of_txd_bytes = 1;
+
+    uint32_t err_code = 0;
+
+
     while (number_of_txd_bytes < transfer_size) {
+        uint32_t timeout = 100000;
+
         // wait for the transaction complete
-        while (p_instance->EVENTS_TXDSENT == 0) {
+        while (p_instance->EVENTS_TXDSENT == 0 && timeout--) {
             ;
         }
+        if (!timeout) {
+            err_code = 1;
+            break;
+        }
 
-        number_of_txd_bytes++;
-
-        // TODO: This could go one byte out of bound.
         p_instance->TXD            = tx_data[number_of_txd_bytes];
         p_instance->EVENTS_TXDSENT = 0;
+
+        number_of_txd_bytes++;
     }
 
 
@@ -88,11 +117,13 @@ void hal_twi_master_tx(NRF_TWI_Type  * p_instance,
             ;
         }
     }
+
+    return err_code;
 }
 
 void hal_twi_master_rx(NRF_TWI_Type  * p_instance,
                        uint8_t         addr,
-                       uint16_t        transfer_size,
+                       size_t          transfer_size,
                        uint8_t       * rx_data,
                        bool            stop) {
 
diff --git a/ports/nrf/hal/hal_twi.h b/ports/nrf/hal/hal_twi.h
index 834c512a0..f912671c4 100644
--- a/ports/nrf/hal/hal_twi.h
+++ b/ports/nrf/hal/hal_twi.h
@@ -99,15 +99,15 @@ typedef struct __TWI_HandleTypeDef
 
 void hal_twi_master_init(NRF_TWI_Type * p_instance, hal_twi_init_t const * p_twi_init);
 
-void hal_twi_master_tx(NRF_TWI_Type  * p_instance,
+uint32_t hal_twi_master_tx(NRF_TWI_Type  * p_instance,
                        uint8_t         addr,
-                       uint16_t        transfer_size,
+                       size_t          transfer_size,
                        const uint8_t * tx_data,
                        bool            stop);
 
 void hal_twi_master_rx(NRF_TWI_Type  * p_instance,
                        uint8_t         addr,
-                       uint16_t        transfer_size,
+                       size_t          transfer_size,
                        uint8_t       * rx_data,
                        bool            stop);
 
diff --git a/ports/nrf/modules/machine/i2c.c b/ports/nrf/modules/machine/i2c.c
index 943599816..e6e5a42d1 100644
--- a/ports/nrf/modules/machine/i2c.c
+++ b/ports/nrf/modules/machine/i2c.c
@@ -29,6 +29,7 @@
 
 #include "py/nlr.h"
 #include "py/runtime.h"
+#include "py/mperrno.h"
 #include "py/mphal.h"
 #include "extmod/machine_i2c.h"
 #include "i2c.h"
@@ -141,7 +142,10 @@ int machine_hard_i2c_readfrom(mp_obj_base_t *self_in, uint16_t addr, uint8_t *de
 int machine_hard_i2c_writeto(mp_obj_base_t *self_in, uint16_t addr, const uint8_t *src, size_t len, bool stop) {
     machine_hard_i2c_obj_t *self = (machine_hard_i2c_obj_t *)self_in;
 
-    hal_twi_master_tx(self->i2c->instance, addr, len, src, stop);
+    // TODO: pass timeout in microseconds
+    if (hal_twi_master_tx(self->i2c->instance, addr, len, src, stop) != 0) {
+        mp_raise_OSError(MP_EIO);
+    }
 
     return 0;
 }
diff --git a/ports/nrf/mpconfigport.h b/ports/nrf/mpconfigport.h
index 61729f6d0..e88c5819f 100644
--- a/ports/nrf/mpconfigport.h
+++ b/ports/nrf/mpconfigport.h
@@ -43,7 +43,7 @@
 #define MICROPY_READER_VFS          (MICROPY_VFS)
 #define MICROPY_ENABLE_GC           (1)
 #define MICROPY_ENABLE_FINALISER    (1)
-#define MICROPY_STACK_CHECK         (0)
+#define MICROPY_STACK_CHECK         (1)
 #define MICROPY_HELPER_REPL         (1)
 #define MICROPY_REPL_EMACS_KEYS     (0)
 #define MICROPY_REPL_AUTO_INDENT    (1)