Add microcontroller.cpu.temperature, for use as a simple sensor on minimal boards. (#211)

* Add microcontroller.cpu, the sole instance of microcontroller.Processor.
microcontroller.cpu.frequency is the clock frequency, in Hz.
microcontroller.cpu.temperature is the reading from the internal temperature sensor, in Celsius. None if not available.

* Squeeze firmware size by using -finline-limit. Otherwise non-Express builds were slightly too big.

* Update submodules.

* Fix documentation glitches

6 files changed, 194 insertions, 19 deletions

diff --git a/shared-bindings/index.rst b/shared-bindings/index.rst
index ab92fd57c..49b6ce5bc 100644
--- a/shared-bindings/index.rst
+++ b/shared-bindings/index.rst
@@ -12,13 +12,28 @@ limited. For example, a microcontroller without analog features will not have
 Support Matrix
 ---------------
 
-===============  ==========  =========  ===========  =======  =======  ===========  =================  ===============  ================  =======  =========  ========  =========  ========  =========  =======  =========
-Port             `analogio`  `audioio`  `bitbangio`  `board`  `busio`  `digitalio`  `microcontroller`  `multiterminal`  `neopixel_write`  `os`     `pulseio`  `random`  `storage`  `time`    `touchio`  `uheap`  `usb_hid`
-===============  ==========  =========  ===========  =======  =======  ===========  =================  ===============  ================  =======  =========  ========  =========  ========  =========  =======  =========
-SAMD21           **Yes**     No         No           **Yes**  **Yes**  **Yes**      **Yes**            No               **Yes**           **Yes**  No         **Yes**   **Yes**    **Yes**   **Yes**    Debug    **Yes**
-SAMD21 Express   **Yes**     **Yes**    **Yes**      **Yes**  **Yes**  **Yes**      **Yes**            No               **Yes**           **Yes**  **Yes**    **Yes**   **Yes**    **Yes**   **Yes**    Debug    **Yes**
-ESP8266          **Yes**     No         **Yes**      **Yes**  **Yes**  **Yes**      **Yes**            **Yes**          **Yes**           **Yes**  No         **Yes**   **Yes**    **Yes**   No         Debug    No
-===============  ==========  =========  ===========  =======  =======  ===========  =================  ===============  ================  =======  =========  ========  =========  ========  =========  =======  =========
+=================  =======  ==============  =======
+Module / Port      SAMD21   SAMD21 Express  ESP8266
+=================  =======  ==============  =======
+`analogio`         **Yes**  **Yes**         **Yes**
+`audioio`          No       **Yes**         No
+`bitbangio`        No       **Yes**         **Yes**
+`board`            **Yes**  **Yes**         **Yes**
+`busio`            **Yes**  **Yes**         **Yes**
+`digitalio`        **Yes**  **Yes**         **Yes**
+`microcontroller`  **Yes**  **Yes**         **Yes**  
+`multiterminal`    No       No              **Yes**
+`neopixel_write`   **Yes**  **Yes**         **Yes**  
+`nvm`              No       **Yes**         No
+`os`               **Yes**  **Yes**         **Yes**
+`pulseio`          No       **Yes**         No
+`random`           **Yes**  **Yes**         **Yes**
+`storage`          **Yes**  **Yes**         **Yes**
+`time`             **Yes**  **Yes**         **Yes**
+`touchio`          **Yes**  **Yes**         No
+`uheap`            Debug    Debug           Debug
+`usb_hid`          **Yes**  **Yes**         No
+=================  =======  ==============  =======
 
 Modules
 ---------
diff --git a/shared-bindings/microcontroller/Processor.c b/shared-bindings/microcontroller/Processor.c
new file mode 100644
index 000000000..0e843bd31
--- /dev/null
+++ b/shared-bindings/microcontroller/Processor.c
@@ -0,0 +1,107 @@
+/*
+ * This file is part of the Micro Python project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2017 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 "shared-bindings/microcontroller/__init__.h"
+#include "shared-bindings/microcontroller/Processor.h"
+
+#include <math.h>
+#include <stdint.h>
+
+#include "py/objproperty.h"
+
+#include "py/objproperty.h"
+#include "py/runtime.h"
+
+//| .. currentmodule:: microcontroller
+//|
+//| :class:`Processor` --- Microcontroller CPU information and control
+//| --------------------------------------------------------
+//|
+//| Get information about the microcontroller CPU and control it.
+//|
+//| Usage::
+//|
+//|    import microcontroller
+//|    print(microcontroller.cpu.frequency)
+//|    print(microcontroller.cpu.temperature)
+//|
+
+//| .. class:: Processor()
+//|
+//| You cannot create an instance of `microcontroller.Processor`.
+//| Use `microcontroller.cpu` to access the sole instance available.
+//|
+
+//| .. attribute:: frequency
+//|
+//|   Return the CPU operating frequency as an int, in Hz.
+//|
+STATIC mp_obj_t mcu_processor_get_frequency(mp_obj_t self) {
+    return mp_obj_new_int_from_uint(common_hal_mcu_processor_get_frequency());
+}
+
+MP_DEFINE_CONST_FUN_OBJ_1(mcu_processor_get_frequency_obj, mcu_processor_get_frequency);
+
+const mp_obj_property_t mcu_processor_frequency_obj = {
+    .base.type = &mp_type_property,
+    .proxy = {(mp_obj_t)&mcu_processor_get_frequency_obj,  // getter
+              (mp_obj_t)&mp_const_none_obj,            // no setter
+              (mp_obj_t)&mp_const_none_obj,            // no deleter
+    },
+};
+
+//| .. attribute:: temperature
+//|
+//|   Return the on-chip temperature, in Celsius, as a float.
+//|   If the temperature is not available, return `None`.
+//|
+STATIC mp_obj_t mcu_processor_get_temperature(mp_obj_t self) {
+    float temperature = common_hal_mcu_processor_get_temperature();
+    return isnan(temperature) ? mp_const_none : mp_obj_new_float(temperature);
+}
+
+MP_DEFINE_CONST_FUN_OBJ_1(mcu_processor_get_temperature_obj, mcu_processor_get_temperature);
+
+const mp_obj_property_t mcu_processor_temperature_obj = {
+    .base.type = &mp_type_property,
+    .proxy = {(mp_obj_t)&mcu_processor_get_temperature_obj,  // getter
+              (mp_obj_t)&mp_const_none_obj,            // no setter
+              (mp_obj_t)&mp_const_none_obj,            // no deleter
+    },
+};
+
+STATIC const mp_rom_map_elem_t mcu_processor_locals_dict_table[] = {
+    { MP_ROM_QSTR(MP_QSTR_frequency), MP_ROM_PTR(&mcu_processor_frequency_obj) },
+    { MP_ROM_QSTR(MP_QSTR_temperature), MP_ROM_PTR(&mcu_processor_temperature_obj) },
+};
+
+STATIC MP_DEFINE_CONST_DICT(mcu_processor_locals_dict, mcu_processor_locals_dict_table);
+
+const mp_obj_type_t mcu_processor_type = {
+    { &mp_type_type },
+    .name = MP_QSTR_Processor,
+    .locals_dict = (mp_obj_t)&mcu_processor_locals_dict,
+};
diff --git a/shared-bindings/microcontroller/Processor.h b/shared-bindings/microcontroller/Processor.h
new file mode 100644
index 000000000..a79dea478
--- /dev/null
+++ b/shared-bindings/microcontroller/Processor.h
@@ -0,0 +1,39 @@
+/*
+ * This file is part of the Micro Python project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2017 Scott Shawcroft 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.
+ */
+
+#ifndef MICROPY_INCLUDED_SHARED_BINDINGS_MICROCONTROLLER_PROCESSOR_H
+#define MICROPY_INCLUDED_SHARED_BINDINGS_MICROCONTROLLER_PROCESSOR_H
+
+#include "py/obj.h"
+
+#include "common-hal/microcontroller/Processor.h"
+
+const mp_obj_type_t mcu_processor_type;
+
+uint32_t common_hal_mcu_processor_get_frequency(void);
+float common_hal_mcu_processor_get_temperature(void);
+
+#endif  // MICROPY_INCLUDED_SHARED_BINDINGS_MICROCONTROLLER_PROCESSOR_H
diff --git a/shared-bindings/microcontroller/__init__.c b/shared-bindings/microcontroller/__init__.c
index 56d363eed..0546ebf30 100644
--- a/shared-bindings/microcontroller/__init__.c
+++ b/shared-bindings/microcontroller/__init__.c
@@ -32,13 +32,17 @@
 #include "py/obj.h"
 #include "py/runtime.h"
 
+#include "common-hal/microcontroller/Pin.h"
+#include "common-hal/microcontroller/Processor.h"
+
 #include "shared-bindings/microcontroller/__init__.h"
 #include "shared-bindings/microcontroller/Pin.h"
-#include "common-hal/microcontroller/Pin.h"
+#include "shared-bindings/microcontroller/Processor.h"
+
 
 #include "py/runtime.h"
 
-//| :mod:`microcontroller` --- Pin references and core functionality
+//| :mod:`microcontroller` --- Pin references and cpu functionality
 //| ================================================================
 //|
 //| .. module:: microcontroller
@@ -56,6 +60,12 @@
 //|     Pin
 //|
 
+//| .. attribute:: cpu
+//|
+//|   CPU information and control, such as temperature and clock frequency.
+//|   This object is the sole instance of `microcontroller.Processor`.
+//|
+
 //| .. method:: delay_us(delay)
 //|
 //|   Dedicated delay method used for very short delays. DO NOT do long delays
@@ -92,8 +102,8 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_0(mcu_enable_interrupts_obj, mcu_enable_interrupt
 
 //| .. attribute:: nvm
 //|
-//|   Available non-volatile memory. Its a `nvm.ByteArray` when available or
-//|   ``None`` otherwise.
+//|   Available non-volatile memory.
+//|   This object is the sole instance of `nvm.ByteArray` when available or ``None`` otherwise.
 //|
 
 //| :mod:`microcontroller.pin` --- Microcontroller pin names
@@ -112,16 +122,19 @@ const mp_obj_module_t mcu_pin_module = {
 
 STATIC const mp_rom_map_elem_t mcu_module_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_microcontroller) },
+    { MP_ROM_QSTR(MP_QSTR_cpu),  MP_ROM_PTR(&common_hal_mcu_processor_obj) },
     { MP_ROM_QSTR(MP_QSTR_delay_us), MP_ROM_PTR(&mcu_delay_us_obj) },
     { MP_ROM_QSTR(MP_QSTR_disable_interrupts), MP_ROM_PTR(&mcu_disable_interrupts_obj) },
     { MP_ROM_QSTR(MP_QSTR_enable_interrupts), MP_ROM_PTR(&mcu_enable_interrupts_obj) },
     #if CIRCUITPY_INTERNAL_NVM_SIZE > 0
-    { MP_ROM_QSTR(MP_QSTR_nvm),  &common_hal_mcu_nvm_obj },
+    { MP_ROM_QSTR(MP_QSTR_nvm),  MP_ROM_PTR(&common_hal_mcu_nvm_obj) },
     #else
-    { MP_ROM_QSTR(MP_QSTR_nvm),  &mp_const_none_obj },
+    { MP_ROM_QSTR(MP_QSTR_nvm),  MP_ROM_PTR(&mp_const_none_obj) },
     #endif
     { MP_ROM_QSTR(MP_QSTR_Pin),  MP_ROM_PTR(&mcu_pin_type) },
     { MP_ROM_QSTR(MP_QSTR_pin),  MP_ROM_PTR(&mcu_pin_module) },
+    { MP_ROM_QSTR(MP_QSTR_Processor),   MP_ROM_PTR(&mcu_processor_type) },
+
 };
 
 STATIC MP_DEFINE_CONST_DICT(mcu_module_globals, mcu_module_globals_table);
diff --git a/shared-bindings/microcontroller/__init__.h b/shared-bindings/microcontroller/__init__.h
index 9bad926cd..d43db4bf4 100644
--- a/shared-bindings/microcontroller/__init__.h
+++ b/shared-bindings/microcontroller/__init__.h
@@ -1,3 +1,4 @@
+
 /*
  * This file is part of the MicroPython project, http://micropython.org/
  *
@@ -30,6 +31,8 @@
 #include "py/mpconfig.h"
 #include "py/obj.h"
 
+#include "common-hal/microcontroller/Processor.h"
+
 extern void common_hal_mcu_delay_us(uint32_t);
 
 extern void common_hal_mcu_disable_interrupts(void);
@@ -37,6 +40,9 @@ extern void common_hal_mcu_enable_interrupts(void);
 
 extern const mp_obj_dict_t mcu_pin_globals;
 
+extern const mcu_processor_obj_t common_hal_mcu_processor_obj;
+
+
 #if CIRCUITPY_INTERNAL_NVM_SIZE > 0
 
 #include "common-hal/nvm/ByteArray.h"
diff --git a/shared-bindings/nvm/ByteArray.c b/shared-bindings/nvm/ByteArray.c
index 0ba511a77..361d03c55 100644
--- a/shared-bindings/nvm/ByteArray.c
+++ b/shared-bindings/nvm/ByteArray.c
@@ -46,12 +46,8 @@
 
 //| .. class:: ByteArray()
 //|
-//|   Not currently dynamically supported. Access one through `microcontroller.nvm`.
+//|   Not currently dynamically supported. Access the sole instance through `microcontroller.nvm`.
 //|
-STATIC mp_obj_t nvm_bytearray_make_new(const mp_obj_type_t *type,
-        mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
-    return mp_const_none;
-}
 
 //|   .. method:: __len__()
 //|
@@ -151,7 +147,6 @@ STATIC mp_obj_t nvm_bytearray_subscr(mp_obj_t self_in, mp_obj_t index_in, mp_obj
 const mp_obj_type_t nvm_bytearray_type = {
     { &mp_type_type },
     .name = MP_QSTR_ByteArray,
-    .make_new = nvm_bytearray_make_new,
     .subscr = nvm_bytearray_subscr,
     .unary_op = nvm_bytearray_unary_op,
     .print = NULL,