.. currentmodule:: esp32 :mod:`esp32` --- functionality specific to the ESP32 ==================================================== .. module:: esp32 :synopsis: functionality specific to the ESP32 The ``esp32`` module contains functions and classes specifically aimed at controlling ESP32 modules. Functions --------- .. function:: wake_on_touch(wake) Configure whether or not a touch will wake the device from sleep. *wake* should be a boolean value. .. function:: wake_on_ext0(pin, level) Configure how EXT0 wakes the device from sleep. *pin* can be ``None`` or a valid Pin object. *level* should be ``esp32.WAKEUP_ALL_LOW`` or ``esp32.WAKEUP_ANY_HIGH``. .. function:: wake_on_ext1(pins, level) Configure how EXT1 wakes the device from sleep. *pins* can be ``None`` or a tuple/list of valid Pin objects. *level* should be ``esp32.WAKEUP_ALL_LOW`` or ``esp32.WAKEUP_ANY_HIGH``. .. function:: raw_temperature() Read the raw value of the internal temperature sensor, returning an integer. .. function:: hall_sensor() Read the raw value of the internal Hall sensor, returning an integer. .. function:: idf_heap_info(capabilities) Returns information about the ESP-IDF heap memory regions. One of them contains the MicroPython heap and the others are used by ESP-IDF, e.g., for network buffers and other data. This data is useful to get a sense of how much memory is available to ESP-IDF and the networking stack in particular. It may shed some light on situations where ESP-IDF operations fail due to allocation failures. The information returned is *not* useful to troubleshoot Python allocation failures, use `micropython.mem_info()` instead. The capabilities parameter corresponds to ESP-IDF's ``MALLOC_CAP_XXX`` values but the two most useful ones are predefined as `esp32.HEAP_DATA` for data heap regions and `esp32.HEAP_EXEC` for executable regions as used by the native code emitter. The return value is a list of 4-tuples, where each 4-tuple corresponds to one heap and contains: the total bytes, the free bytes, the largest free block, and the minimum free seen over time. Example after booting:: >>> import esp32; esp32.idf_heap_info(esp32.HEAP_DATA) [(240, 0, 0, 0), (7288, 0, 0, 0), (16648, 4, 4, 4), (79912, 35712, 35512, 35108), (15072, 15036, 15036, 15036), (113840, 0, 0, 0)] Flash partitions ---------------- This class gives access to the partitions in the device's flash memory and includes methods to enable over-the-air (OTA) updates. .. class:: Partition(id) Create an object representing a partition. *id* can be a string which is the label of the partition to retrieve, or one of the constants: ``BOOT`` or ``RUNNING``. .. classmethod:: Partition.find(type=TYPE_APP, subtype=0xff, label=None) Find a partition specified by *type*, *subtype* and *label*. Returns a (possibly empty) list of Partition objects. Note: ``subtype=0xff`` matches any subtype and ``label=None`` matches any label. .. method:: Partition.info() Returns a 6-tuple ``(type, subtype, addr, size, label, encrypted)``. .. method:: Partition.readblocks(block_num, buf) Partition.readblocks(block_num, buf, offset) .. method:: Partition.writeblocks(block_num, buf) Partition.writeblocks(block_num, buf, offset) .. method:: Partition.ioctl(cmd, arg) These methods implement the simple and :ref:`extended ` block protocol defined by :class:`uos.AbstractBlockDev`. .. method:: Partition.set_boot() Sets the partition as the boot partition. .. method:: Partition.get_next_update() Gets the next update partition after this one, and returns a new Partition object. Typical usage is ``Partition(Partition.RUNNING).get_next_update()`` which returns the next partition to update given the current running one. .. classmethod:: Partition.mark_app_valid_cancel_rollback() Signals that the current boot is considered successful. Calling ``mark_app_valid_cancel_rollback`` is required on the first boot of a new partition to avoid an automatic rollback at the next boot. This uses the ESP-IDF "app rollback" feature with "CONFIG_BOOTLOADER_APP_ROLLBACK_ENABLE" and an ``OSError(-261)`` is raised if called on firmware that doesn't have the feature enabled. It is OK to call ``mark_app_valid_cancel_rollback`` on every boot and it is not necessary when booting firmare that was loaded using esptool. Constants ~~~~~~~~~ .. data:: Partition.BOOT Partition.RUNNING Used in the `Partition` constructor to fetch various partitions: ``BOOT`` is the partition that will be booted at the next reset and ``RUNNING`` is the currently running partition. .. data:: Partition.TYPE_APP Partition.TYPE_DATA Used in `Partition.find` to specify the partition type: ``APP`` is for bootable firmware partitions (typically labelled ``factory``, ``ota_0``, ``ota_1``), and ``DATA`` is for other partitions, e.g. ``nvs``, ``otadata``, ``phy_init``, ``vfs``. .. data:: HEAP_DATA HEAP_EXEC Used in `idf_heap_info`. .. _esp32.RMT: RMT --- The RMT (Remote Control) module, specific to the ESP32, was originally designed to send and receive infrared remote control signals. However, due to a flexible design and very accurate (as low as 12.5ns) pulse generation, it can also be used to transmit or receive many other types of digital signals:: import esp32 from machine import Pin r = esp32.RMT(0, pin=Pin(18), clock_div=8) r # RMT(channel=0, pin=18, source_freq=80000000, clock_div=8) # To use carrier frequency r = esp32.RMT(0, pin=Pin(18), clock_div=8, carrier_freq=38000) r # RMT(channel=0, pin=18, source_freq=80000000, clock_div=8, carrier_freq=38000, carrier_duty_percent=50) # The channel resolution is 100ns (1/(source_freq/clock_div)). r.write_pulses((1, 20, 2, 40), start=0) # Send 0 for 100ns, 1 for 2000ns, 0 for 200ns, 1 for 4000ns The input to the RMT module is an 80MHz clock (in the future it may be able to configure the input clock but, for now, it's fixed). ``clock_div`` *divides* the clock input which determines the resolution of the RMT channel. The numbers specified in ``write_pulses`` are multiplied by the resolution to define the pulses. ``clock_div`` is an 8-bit divider (0-255) and each pulse can be defined by multiplying the resolution by a 15-bit (0-32,768) number. There are eight channels (0-7) and each can have a different clock divider. To enable the carrier frequency feature of the esp32 hardware, specify the ``carrier_freq`` as something like 38000, a typical IR carrier frequency. So, in the example above, the 80MHz clock is divided by 8. Thus the resolution is (1/(80Mhz/8)) 100ns. Since the ``start`` level is 0 and toggles with each number, the bitstream is ``0101`` with durations of [100ns, 2000ns, 100ns, 4000ns]. For more details see Espressif's `ESP-IDF RMT documentation. `_. .. Warning:: The current MicroPython RMT implementation lacks some features, most notably receiving pulses. RMT should be considered a *beta feature* and the interface may change in the future. .. class:: RMT(channel, *, pin=None, clock_div=8, carrier_freq=0, carrier_duty_percent=50) This class provides access to one of the eight RMT channels. *channel* is required and identifies which RMT channel (0-7) will be configured. *pin*, also required, configures which Pin is bound to the RMT channel. *clock_div* is an 8-bit clock divider that divides the source clock (80MHz) to the RMT channel allowing the resolution to be specified. *carrier_freq* is used to enable the carrier feature and specify its frequency, default value is ``0`` (not enabled). To enable, specify a positive integer. *carrier_duty_percent* defaults to 50. .. method:: RMT.source_freq() Returns the source clock frequency. Currently the source clock is not configurable so this will always return 80MHz. .. method:: RMT.clock_div() Return the clock divider. Note that the channel resolution is ``1 / (source_freq / clock_div)``. .. method:: RMT.wait_done(timeout=0) Returns ``True`` if the channel is currently transmitting a stream of pulses started with a call to `RMT.write_pulses`. If *timeout* (defined in ticks of ``source_freq / clock_div``) is specified the method will wait for *timeout* or until transmission is complete, returning ``False`` if the channel continues to transmit. If looping is enabled with `RMT.loop` and a stream has started, then this method will always (wait and) return ``False``. .. method:: RMT.loop(enable_loop) Configure looping on the channel. *enable_loop* is bool, set to ``True`` to enable looping on the *next* call to `RMT.write_pulses`. If called with ``False`` while a looping stream is currently being transmitted then the current set of pulses will be completed before transmission stops. .. method:: RMT.write_pulses(pulses, start) Begin sending *pulses*, a list or tuple defining the stream of pulses. The length of each pulse is defined by a number to be multiplied by the channel resolution ``(1 / (source_freq / clock_div))``. *start* defines whether the stream starts at 0 or 1. If transmission of a stream is currently in progress then this method will block until transmission of that stream has ended before beginning sending *pulses*. If looping is enabled with `RMT.loop`, the stream of pulses will be repeated indefinitely. Further calls to `RMT.write_pulses` will end the previous stream - blocking until the last set of pulses has been transmitted - before starting the next stream. Ultra-Low-Power co-processor ---------------------------- .. class:: ULP() This class provides access to the Ultra-Low-Power co-processor. .. method:: ULP.set_wakeup_period(period_index, period_us) Set the wake-up period. .. method:: ULP.load_binary(load_addr, program_binary) Load a *program_binary* into the ULP at the given *load_addr*. .. method:: ULP.run(entry_point) Start the ULP running at the given *entry_point*. Constants --------- .. data:: esp32.WAKEUP_ALL_LOW esp32.WAKEUP_ANY_HIGH Selects the wake level for pins. Non-Volatile Storage -------------------- This class gives access to the Non-Volatile storage managed by ESP-IDF. The NVS is partitioned into namespaces and each namespace contains typed key-value pairs. The keys are strings and the values may be various integer types, strings, and binary blobs. The driver currently only supports 32-bit signed integers and blobs. .. warning:: Changes to NVS need to be committed to flash by calling the commit method. Failure to call commit results in changes being lost at the next reset. .. class:: NVS(namespace) Create an object providing access to a namespace (which is automatically created if not present). .. method:: NVS.set_i32(key, value) Sets a 32-bit signed integer value for the specified key. Remember to call *commit*! .. method:: NVS.get_i32(key) Returns the signed integer value for the specified key. Raises an OSError if the key does not exist or has a different type. .. method:: NVS.set_blob(key, value) Sets a binary blob value for the specified key. The value passed in must support the buffer protocol, e.g. bytes, bytearray, str. (Note that esp-idf distinguishes blobs and strings, this method always writes a blob even if a string is passed in as value.) Remember to call *commit*! .. method:: NVS.get_blob(key, buffer) Reads the value of the blob for the specified key into the buffer, which must be a bytearray. Returns the actual length read. Raises an OSError if the key does not exist, has a different type, or if the buffer is too small. .. method:: NVS.erase_key(key) Erases a key-value pair. .. method:: NVS.commit() Commits changes made by *set_xxx* methods to flash.