add CharacteristicBuffer; UART seems to work!

17 files changed, 395 insertions, 79 deletions

diff --git a/ports/nrf/.gitignore b/ports/nrf/.gitignore
index fc9f24b50..cda23c7a9 100644
--- a/ports/nrf/.gitignore
+++ b/ports/nrf/.gitignore
@@ -1,8 +1,8 @@
 # Old Nordic soft devices that don't allow redistribution
 #########################################################
-bluetooth/s132_nrf52_2.0.1/
+drivers/bluetooth/s132_nrf52_2.0.1/
 
-!bluetooth/*/*.hex
+!drivers/bluetooth/*/*.hex
 
 # Build files
 #####################
diff --git a/ports/nrf/Makefile b/ports/nrf/Makefile
index f7e4a2988..2e345b9c7 100755
--- a/ports/nrf/Makefile
+++ b/ports/nrf/Makefile
@@ -174,6 +174,7 @@ SRC_COMMON_HAL += \
 	bleio/Adapter.c \
 	bleio/Broadcaster.c \
 	bleio/Characteristic.c \
+	bleio/CharacteristicBuffer.c \
 	bleio/Descriptor.c \
 	bleio/Peripheral.c \
 	bleio/Scanner.c \
diff --git a/ports/nrf/bluetooth/ble_drv.c b/ports/nrf/bluetooth/ble_drv.c
index 7082b1e59..cdc56319b 100644
--- a/ports/nrf/bluetooth/ble_drv.c
+++ b/ports/nrf/bluetooth/ble_drv.c
@@ -71,6 +71,20 @@ void ble_drv_add_event_handler(ble_drv_evt_handler_t func, void *param) {
     m_event_handlers = handler;
 }
 
+void ble_drv_remove_event_handler(ble_drv_evt_handler_t func, void *param) {
+    event_handler_t *it = m_event_handlers;
+    event_handler_t **prev = &m_event_handlers;
+    while (it != NULL) {
+        if ((it->func == func) && (it->param == param)) {
+            // Splice out the matching handler.
+            *prev = it->next;
+            return;
+        }
+        prev = &(it->next);
+        it = it->next;
+    }
+}
+
 void SD_EVT_IRQHandler(void) {
     uint32_t evt_id;
     while (sd_evt_get(&evt_id) != NRF_ERROR_NOT_FOUND) {
diff --git a/ports/nrf/bluetooth/ble_drv.h b/ports/nrf/bluetooth/ble_drv.h
index 696aff1da..3d1f551c5 100644
--- a/ports/nrf/bluetooth/ble_drv.h
+++ b/ports/nrf/bluetooth/ble_drv.h
@@ -52,5 +52,6 @@ typedef void (*ble_drv_evt_handler_t)(ble_evt_t*, void*);
 
 void ble_drv_reset();
 void ble_drv_add_event_handler(ble_drv_evt_handler_t func, void *param);
+void ble_drv_remove_event_handler(ble_drv_evt_handler_t func, void *param);
 
 #endif // MICROPY_INCLUDED_NRF_BLUETOOTH_BLE_DRV_H
diff --git a/ports/nrf/bluetooth/download_ble_stack.sh b/ports/nrf/bluetooth/download_ble_stack.sh
deleted file mode 100755
index 7e35c0680..000000000
--- a/ports/nrf/bluetooth/download_ble_stack.sh
+++ /dev/null
@@ -1,32 +0,0 @@
-#!/bin/bash
-
-function download_s132_nrf52_2_0_1
-{
-    echo ""
-    echo "####################################"
-    echo "### Downloading s132_nrf52_2.0.1 ###"
-    echo "####################################"
-    echo ""
-
-    mkdir -p "${1}/s132_nrf52_2.0.1"
-    cd "${1}/s132_nrf52_2.0.1"
-    wget https://www.nordicsemi.com/api/sitecore/Products/MedialibraryZipDownload2 --post-data="ids=863031714A574444AADFE444EBE5BA9B|&fileName=DeviceDownload" -O temp.zip
-    unzip -u temp.zip
-    unzip -u s132nrf52201.zip
-    rm temp.zip s132nrf52201.zip
-    cd -
-}
-
-SCRIPT_DIR="$(cd -P "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
-
-if [ $# -eq 0 ]; then
-    echo "No Bluetooth LE stack defined, downloading all."
-    download_s132_nrf52_2_0_1 "${SCRIPT_DIR}"
-else
-    case $1 in
-        "s132_nrf52_2_0_1" )
-            download_s132_nrf52_2_0_1 "${SCRIPT_DIR}" ;;
-    esac
-fi
-
-exit 0
diff --git a/ports/nrf/common-hal/bleio/Characteristic.c b/ports/nrf/common-hal/bleio/Characteristic.c
index a955395bd..bebdb31fa 100644
--- a/ports/nrf/common-hal/bleio/Characteristic.c
+++ b/ports/nrf/common-hal/bleio/Characteristic.c
@@ -33,6 +33,7 @@
 
 #include "py/runtime.h"
 #include "common-hal/bleio/__init__.h"
+#include "common-hal/bleio/Characteristic.h"
 #include "shared-module/bleio/Characteristic.h"
 
 // TODO - should these be per object?? *****
@@ -190,28 +191,41 @@ STATIC void gattc_write(bleio_characteristic_obj_t *characteristic, mp_buffer_in
 
 STATIC void characteristic_on_ble_evt(ble_evt_t *ble_evt, void *param) {
     switch (ble_evt->header.evt_id) {
-        case BLE_GATTS_EVT_HVN_TX_COMPLETE:
-            m_tx_in_progress -= ble_evt->evt.gatts_evt.params.hvn_tx_complete.count;
-            break;
-
-        case BLE_GATTC_EVT_READ_RSP:
-        {
-            ble_gattc_evt_read_rsp_t *response = &ble_evt->evt.gattc_evt.params.read_rsp;
-            m_read_characteristic->value_data = mp_obj_new_bytearray(response->len, response->data);
-            // Flag to busy-wait loop that we've read the characteristic.
-            m_read_characteristic = NULL;
-            break;
-        }
+    case BLE_GATTS_EVT_HVN_TX_COMPLETE:
+        m_tx_in_progress -= ble_evt->evt.gatts_evt.params.hvn_tx_complete.count;
+        break;
+
+    case BLE_GATTC_EVT_READ_RSP:
+    {
+        ble_gattc_evt_read_rsp_t *response = &ble_evt->evt.gattc_evt.params.read_rsp;
+        m_read_characteristic->value_data = mp_obj_new_bytearray(response->len, response->data);
+        // Flag to busy-wait loop that we've read the characteristic.
+        m_read_characteristic = NULL;
+        break;
+    }
+
+    case BLE_GATTC_EVT_WRITE_RSP:
+        // Someone else can write now.
+        sd_mutex_release(m_write_mutex);
+        break;
 
-        case BLE_GATTC_EVT_WRITE_RSP:
-            // Someone else can write now.
-            sd_mutex_release(m_write_mutex);
-            break;
+        // For debugging.
+    default:
+        mp_printf(&mp_plat_print, "Unhandled characteristic event: 0x%04x\n", ble_evt->header.evt_id);
+        break;
     }
+
 }
 
-void common_hal_bleio_characteristic_construct(bleio_characteristic_obj_t *self) {
-    ble_drv_add_event_handler(characteristic_on_ble_evt, NULL);
+void common_hal_bleio_characteristic_construct(bleio_characteristic_obj_t *self, bleio_uuid_obj_t *uuid, bleio_characteristic_properties_t props) {
+    self->service = NULL;
+    self->uuid = uuid;
+    self->value_data = NULL;
+    self->props = props;
+    self->handle = BLE_GATT_HANDLE_INVALID;
+
+    ble_drv_add_event_handler(characteristic_on_ble_evt, self);
+
 }
 
 void common_hal_bleio_characteristic_get_value(bleio_characteristic_obj_t *self) {
diff --git a/ports/nrf/common-hal/bleio/Characteristic.h b/ports/nrf/common-hal/bleio/Characteristic.h
new file mode 100644
index 000000000..bce1eec1d
--- /dev/null
+++ b/ports/nrf/common-hal/bleio/Characteristic.h
@@ -0,0 +1,46 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2018 Artur Pacholec
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef MICROPY_INCLUDED_COMMON_HAL_BLEIO_CHARACTERISTIC_H
+#define MICROPY_INCLUDED_COMMON_HAL_BLEIO_CHARACTERISTIC_H
+
+#include "shared-module/bleio/Characteristic.h"
+#include "shared-module/bleio/Service.h"
+#include "common-hal/bleio/UUID.h"
+
+typedef struct {
+    mp_obj_base_t base;
+    bleio_service_obj_t *service;
+    bleio_uuid_obj_t *uuid;
+    mp_obj_t value_data;
+    uint16_t handle;
+    bleio_characteristic_properties_t props;
+    uint16_t user_desc_handle;
+    uint16_t cccd_handle;
+    uint16_t sccd_handle;
+} bleio_characteristic_obj_t;
+
+#endif // MICROPY_INCLUDED_COMMON_HAL_BLEIO_CHARACTERISTIC_H
diff --git a/ports/nrf/common-hal/bleio/CharacteristicBuffer.c b/ports/nrf/common-hal/bleio/CharacteristicBuffer.c
new file mode 100644
index 000000000..4bd3e147f
--- /dev/null
+++ b/ports/nrf/common-hal/bleio/CharacteristicBuffer.c
@@ -0,0 +1,75 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2018 Artur Pacholec
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <string.h>
+#include <stdio.h>
+
+#include "ble_drv.h"
+#include "ble_gatts.h"
+#include "nrf_soc.h"
+
+#include "py/runtime.h"
+
+#include "common-hal/bleio/__init__.h"
+#include "common-hal/bleio/CharacteristicBuffer.h"
+
+STATIC void characteristic_buffer_on_ble_evt(ble_evt_t *ble_evt, void *param) {
+    bleio_characteristic_buffer_obj_t *self = (bleio_characteristic_buffer_obj_t *) param;
+    switch (ble_evt->header.evt_id) {
+    case BLE_GATTS_EVT_WRITE: {
+        ble_gatts_evt_write_t *evt_write = &ble_evt->evt.gatts_evt.params.write;
+        // Event handle must match the handle for my characteristic.
+        if (evt_write->handle == self->characteristic->handle) {
+            // Push all the data onto the ring buffer.
+            for (size_t i = 0; i < evt_write->len; i++) {
+                ringbuf_put(&self->ringbuf, evt_write->data[i]);
+            }
+        break;
+        }
+    }
+    }
+
+}
+
+// Assumes that buffer_size has been validated before call.
+void common_hal_bleio_characteristic_buffer_construct(bleio_characteristic_buffer_obj_t *self, bleio_characteristic_obj_t *characteristic, size_t buffer_size) {
+
+    self->characteristic = characteristic;
+    // This is a macro.
+    ringbuf_alloc(&self->ringbuf, buffer_size);
+
+    ble_drv_add_event_handler(characteristic_buffer_on_ble_evt, self);
+
+}
+
+// Returns a uint8_t byte value, or -1 if no data is available.
+int common_hal_bleio_characteristic_buffer_read(bleio_characteristic_buffer_obj_t *self) {
+    return ringbuf_get(&self->ringbuf);
+}
+
+void common_hal_bleio_characteristic_buffer_deinit(bleio_characteristic_buffer_obj_t *self) {
+    ble_drv_remove_event_handler(characteristic_buffer_on_ble_evt, self);
+}
diff --git a/ports/nrf/common-hal/bleio/CharacteristicBuffer.h b/ports/nrf/common-hal/bleio/CharacteristicBuffer.h
new file mode 100644
index 000000000..f9ff7dd66
--- /dev/null
+++ b/ports/nrf/common-hal/bleio/CharacteristicBuffer.h
@@ -0,0 +1,41 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2018 Artur Pacholec
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef MICROPY_INCLUDED_COMMON_HAL_BLEIO_CHARACTERISTICBUFFER_H
+#define MICROPY_INCLUDED_COMMON_HAL_BLEIO_CHARACTERISTICBUFFER_H
+
+#include "py/ringbuf.h"
+
+#include "shared-bindings/bleio/Characteristic.h"
+
+typedef struct {
+    mp_obj_base_t base;
+    bleio_characteristic_obj_t *characteristic;
+    // Ring buffer storing consecutive incoming values.
+    ringbuf_t ringbuf;
+} bleio_characteristic_buffer_obj_t;
+
+#endif // MICROPY_INCLUDED_COMMON_HAL_BLEIO_CHARACTERISTICBUFFER_H
diff --git a/ports/nrf/common-hal/bleio/Peripheral.c b/ports/nrf/common-hal/bleio/Peripheral.c
index 7d5d6a6a6..0f2506de0 100644
--- a/ports/nrf/common-hal/bleio/Peripheral.c
+++ b/ports/nrf/common-hal/bleio/Peripheral.c
@@ -268,7 +268,7 @@ STATIC void peripheral_on_ble_evt(ble_evt_t *ble_evt, void *self_in) {
     }
 
     default:
-        mp_printf(&mp_plat_print, "Unhandled event: 0x%04x\n", ble_evt->header.evt_id);
+        mp_printf(&mp_plat_print, "Unhandled peripheral event: 0x%04x\n", ble_evt->header.evt_id);
         break;
     }
 }
diff --git a/ports/nrf/common-hal/bleio/Service.c b/ports/nrf/common-hal/bleio/Service.c
index c913c02ae..26a1f1cff 100644
--- a/ports/nrf/common-hal/bleio/Service.c
+++ b/ports/nrf/common-hal/bleio/Service.c
@@ -28,6 +28,7 @@
 #include "ble.h"
 #include "py/runtime.h"
 #include "common-hal/bleio/__init__.h"
+#include "common-hal/bleio/Characteristic.h"
 #include "shared-bindings/bleio/Service.h"
 #include "shared-bindings/bleio/Adapter.h"
 
@@ -87,6 +88,10 @@ void common_hal_bleio_service_add_all_characteristics(bleio_service_obj_t *self)
             mp_raise_OSError_msg_varg(translate("Failed to add characteristic, err 0x%04x"), err_code);
         }
 
+        if (characteristic->handle != BLE_GATT_HANDLE_INVALID) {
+            mp_raise_ValueError(translate("Characteristic already in use by another Service."));
+        }
+
         characteristic->user_desc_handle = handles.user_desc_handle;
         characteristic->cccd_handle = handles.cccd_handle;
         characteristic->sccd_handle = handles.sccd_handle;
diff --git a/shared-bindings/bleio/Characteristic.c b/shared-bindings/bleio/Characteristic.c
index 1d414b6d3..0a3fada13 100644
--- a/shared-bindings/bleio/Characteristic.c
+++ b/shared-bindings/bleio/Characteristic.c
@@ -55,13 +55,13 @@ STATIC mp_obj_t bleio_characteristic_make_new(const mp_obj_type_t *type, size_t
     mp_arg_check_num(n_args, n_kw, 1, 1, true);
     bleio_characteristic_obj_t *self = m_new_obj(bleio_characteristic_obj_t);
     self->base.type = &bleio_characteristic_type;
-    self->service = NULL;
-    self->value_data = NULL;
 
     mp_map_t kw_args;
     mp_map_init_fixed_table(&kw_args, n_kw, pos_args + n_args);
 
-    enum { ARG_uuid, ARG_broadcast, ARG_indicate, ARG_notify, ARG_read, ARG_write, ARG_write_no_response };
+    enum {
+        ARG_uuid, ARG_broadcast, ARG_indicate, ARG_notify, ARG_read, ARG_write, ARG_write_no_response,
+    };
     static const mp_arg_t allowed_args[] = {
         { MP_QSTR_uuid,  MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = mp_const_none} },
         { MP_QSTR_broadcast, MP_ARG_KW_ONLY| MP_ARG_BOOL, {.u_bool = false} },
@@ -83,14 +83,16 @@ STATIC mp_obj_t bleio_characteristic_make_new(const mp_obj_type_t *type, size_t
 
     self->uuid = MP_OBJ_TO_PTR(uuid);
 
-    self->props.broadcast = args[ARG_broadcast].u_bool;
-    self->props.indicate = args[ARG_indicate].u_bool;
-    self->props.notify = args[ARG_notify].u_bool;
-    self->props.read = args[ARG_read].u_bool;
-    self->props.write = args[ARG_write].u_bool;
-    self->props.write_no_response = args[ARG_write_no_response].u_bool;
+    bleio_characteristic_properties_t properties;
+
+    properties.broadcast = args[ARG_broadcast].u_bool;
+    properties.indicate = args[ARG_indicate].u_bool;
+    properties.notify = args[ARG_notify].u_bool;
+    properties.read = args[ARG_read].u_bool;
+    properties.write = args[ARG_write].u_bool;
+    properties.write_no_response = args[ARG_write_no_response].u_bool;
 
-    common_hal_bleio_characteristic_construct(self);
+    common_hal_bleio_characteristic_construct(self, uuid, properties);
 
     return MP_OBJ_FROM_PTR(self);
 }
diff --git a/shared-bindings/bleio/Characteristic.h b/shared-bindings/bleio/Characteristic.h
index aec60ebbc..206cbcd40 100644
--- a/shared-bindings/bleio/Characteristic.h
+++ b/shared-bindings/bleio/Characteristic.h
@@ -27,11 +27,11 @@
 #ifndef MICROPY_INCLUDED_SHARED_BINDINGS_BLEIO_CHARACTERISTIC_H
 #define MICROPY_INCLUDED_SHARED_BINDINGS_BLEIO_CHARACTERISTIC_H
 
-#include "shared-module/bleio/Characteristic.h"
+#include "common-hal/bleio/Characteristic.h"
 
 extern const mp_obj_type_t bleio_characteristic_type;
 
-extern void common_hal_bleio_characteristic_construct(bleio_characteristic_obj_t *self);
+extern void common_hal_bleio_characteristic_construct(bleio_characteristic_obj_t *self, bleio_uuid_obj_t *uuid, bleio_characteristic_properties_t props);
 extern void common_hal_bleio_characteristic_get_value(bleio_characteristic_obj_t *self);
 extern void common_hal_bleio_characteristic_set_value(bleio_characteristic_obj_t *self, mp_buffer_info_t *bufinfo);
 
diff --git a/shared-bindings/bleio/CharacteristicBuffer.c b/shared-bindings/bleio/CharacteristicBuffer.c
new file mode 100644
index 000000000..770594d3a
--- /dev/null
+++ b/shared-bindings/bleio/CharacteristicBuffer.c
@@ -0,0 +1,119 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2018 Dan Halbert for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "py/objproperty.h"
+#include "py/runtime.h"
+#include "shared-bindings/bleio/CharacteristicBuffer.h"
+#include "shared-bindings/bleio/UUID.h"
+
+//| .. currentmodule:: bleio
+//|
+//| :class:`CharacteristicBuffer` -- GATT Service incoming values buffer.
+//| =========================================================
+//|
+//| Accumulates a Characteristic's incoming values in a FIFO buffer.
+//|
+//| .. class:: CharacteristicBuffer(Characteristic, buffer_size=0)
+//|
+//|   Create a new Characteristic object identified by the specified UUID.
+//|
+//|   :param bleio.Characteristic characteristic: The characteristic to monitor
+//|   :param int buffer_size: Size of ring buffer that stores incoming data coming from client.
+//|   Must be >= 1.
+STATIC mp_obj_t bleio_characteristic_buffer_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *pos_args) {
+    mp_arg_check_num(n_args, n_kw, 1, 2, true);
+    bleio_characteristic_buffer_obj_t *self = m_new_obj(bleio_characteristic_buffer_obj_t);
+    self->base.type = &bleio_characteristic_buffer_type;
+
+    mp_map_t kw_args;
+    mp_map_init_fixed_table(&kw_args, n_kw, pos_args + n_args);
+
+    enum { ARG_characteristic, ARG_buffer_size, };
+    static const mp_arg_t allowed_args[] = {
+        { MP_QSTR_characteristic,  MP_ARG_REQUIRED | MP_ARG_OBJ },
+        { MP_QSTR_buffer_size, MP_ARG_REQUIRED | MP_ARG_INT },
+    };
+
+    mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
+    mp_arg_parse_all(n_args, pos_args, &kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
+
+    const mp_obj_t characteristic = args[ARG_characteristic].u_obj;
+    const int buffer_size = args[ARG_buffer_size].u_int;
+
+    if (buffer_size < 1) {
+        mp_raise_ValueError(translate("buffer_size must be >= 1"));
+    }
+
+    if (!MP_OBJ_IS_TYPE(characteristic, &bleio_characteristic_type)) {
+        mp_raise_ValueError(translate("Expected a Characteristic"));
+    }
+
+    self->characteristic = MP_OBJ_TO_PTR(characteristic);
+
+    common_hal_bleio_characteristic_buffer_construct(self, self->characteristic, buffer_size);
+
+    return MP_OBJ_FROM_PTR(self);
+}
+
+
+//|   .. method:: read()
+//|
+//|     Read a single byte from the buffer. If no character is available, return None.
+STATIC mp_obj_t bleio_characteristic_buffer_read(mp_obj_t self_in) {
+    bleio_characteristic_buffer_obj_t *self = MP_OBJ_TO_PTR(self_in);
+
+    int byte = common_hal_bleio_characteristic_buffer_read(self);
+    if (byte == -1) {
+        return mp_const_none;
+    }
+
+    return MP_OBJ_NEW_SMALL_INT(byte);
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(bleio_characteristic_buffer_read_obj, bleio_characteristic_buffer_read);
+
+//|   .. method:: deinit()
+//|
+//|     Disable permanently.
+STATIC mp_obj_t bleio_characteristic_buffer_deinit(mp_obj_t self_in) {
+    bleio_characteristic_buffer_obj_t *self = MP_OBJ_TO_PTR(self_in);
+    common_hal_bleio_characteristic_buffer_deinit(self);
+    return mp_const_none;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_1(bleio_characteristic_buffer_deinit_obj, bleio_characteristic_buffer_deinit);
+
+STATIC const mp_rom_map_elem_t bleio_characteristic_buffer_locals_dict_table[] = {
+    { MP_ROM_QSTR(MP_QSTR_read),          MP_ROM_PTR(&bleio_characteristic_buffer_read_obj) },
+    { MP_ROM_QSTR(MP_QSTR_deinit),        MP_ROM_PTR(&bleio_characteristic_buffer_deinit_obj) },
+};
+
+STATIC MP_DEFINE_CONST_DICT(bleio_characteristic_buffer_locals_dict, bleio_characteristic_buffer_locals_dict_table);
+
+const mp_obj_type_t bleio_characteristic_buffer_type = {
+    { &mp_type_type },
+    .name = MP_QSTR_CharacteristicBuffer,
+    .make_new = bleio_characteristic_buffer_make_new,
+    .locals_dict = (mp_obj_dict_t*)&bleio_characteristic_buffer_locals_dict
+};
diff --git a/shared-bindings/bleio/CharacteristicBuffer.h b/shared-bindings/bleio/CharacteristicBuffer.h
new file mode 100644
index 000000000..c5d7580da
--- /dev/null
+++ b/shared-bindings/bleio/CharacteristicBuffer.h
@@ -0,0 +1,39 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2018 Artur Pacholec
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef MICROPY_INCLUDED_SHARED_BINDINGS_BLEIO_CHARACTERISTICBUFFER_H
+#define MICROPY_INCLUDED_SHARED_BINDINGS_BLEIO_CHARACTERISTICBUFFER_H
+
+#include "common-hal/bleio/CharacteristicBuffer.h"
+
+extern const mp_obj_type_t bleio_characteristic_buffer_type;
+
+extern void common_hal_bleio_characteristic_buffer_construct(bleio_characteristic_buffer_obj_t *self, bleio_characteristic_obj_t *characteristic, size_t buffer_size);
+// Returns a uint8_t byte value, or -1 if no data is available.
+int common_hal_bleio_characteristic_buffer_read(bleio_characteristic_buffer_obj_t *self);
+int common_hal_bleio_characteristic_buffer_deinit(bleio_characteristic_buffer_obj_t *self);
+
+#endif // MICROPY_INCLUDED_SHARED_BINDINGS_BLEIO_CHARACTERISTICBUFFER_H
diff --git a/shared-bindings/bleio/__init__.c b/shared-bindings/bleio/__init__.c
index d30d59942..e23efe36c 100644
--- a/shared-bindings/bleio/__init__.c
+++ b/shared-bindings/bleio/__init__.c
@@ -31,6 +31,7 @@
 #include "shared-bindings/bleio/AdvertisementData.h"
 #include "shared-bindings/bleio/Broadcaster.h"
 #include "shared-bindings/bleio/Characteristic.h"
+#include "shared-bindings/bleio/CharacteristicBuffer.h"
 #include "shared-bindings/bleio/Descriptor.h"
 #include "shared-bindings/bleio/Peripheral.h"
 #include "shared-bindings/bleio/ScanEntry.h"
@@ -77,6 +78,7 @@ STATIC const mp_rom_map_elem_t bleio_module_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR_AdvertisementData), MP_ROM_PTR(&bleio_advertisementdata_type) },
     { MP_ROM_QSTR(MP_QSTR_Broadcaster),       MP_ROM_PTR(&bleio_broadcaster_type) },
     { MP_ROM_QSTR(MP_QSTR_Characteristic),    MP_ROM_PTR(&bleio_characteristic_type) },
+    { MP_ROM_QSTR(MP_QSTR_CharacteristicBuffer),    MP_ROM_PTR(&bleio_characteristic_buffer_type) },
     { MP_ROM_QSTR(MP_QSTR_Descriptor),        MP_ROM_PTR(&bleio_descriptor_type) },
     { MP_ROM_QSTR(MP_QSTR_Peripheral),        MP_ROM_PTR(&bleio_peripheral_type) },
     { MP_ROM_QSTR(MP_QSTR_ScanEntry),         MP_ROM_PTR(&bleio_scanentry_type) },
diff --git a/shared-module/bleio/Characteristic.h b/shared-module/bleio/Characteristic.h
index 977ec8197..958837e64 100644
--- a/shared-module/bleio/Characteristic.h
+++ b/shared-module/bleio/Characteristic.h
@@ -27,26 +27,15 @@
 #ifndef MICROPY_INCLUDED_SHARED_MODULE_BLEIO_CHARACTERISTIC_H
 #define MICROPY_INCLUDED_SHARED_MODULE_BLEIO_CHARACTERISTIC_H
 
-#include "shared-module/bleio/Service.h"
-#include "common-hal/bleio/UUID.h"
-
+// Flags for each characteristic property. Common across ports.
 typedef struct {
-    mp_obj_base_t base;
-    bleio_service_obj_t *service;
-    bleio_uuid_obj_t *uuid;
-    mp_obj_t value_data;
-    uint16_t handle;
-    struct {
         bool broadcast : 1;
         bool read : 1;
         bool write_no_response : 1;
         bool write : 1;
         bool notify : 1;
         bool indicate : 1;
-    } props;
-    uint16_t user_desc_handle;
-    uint16_t cccd_handle;
-    uint16_t sccd_handle;
-} bleio_characteristic_obj_t;
+} bleio_characteristic_properties_t;
+
 
 #endif // MICROPY_INCLUDED_SHARED_MODULE_BLEIO_CHARACTERISTIC_H