esp32 — functionality specific to the ESP32¶
esp32 module contains functions and classes specifically aimed at
controlling ESP32 modules.
Configure whether or not a touch will wake the device from sleep. wake should be a boolean value.
Configure whether or not the Ultra-Low-Power co-processor can wake the device from sleep. wake should be a boolean value.
- esp32.wake_on_ext0(pin, level)¶
Configure how EXT0 wakes the device from sleep. pin can be
Noneor a valid Pin object. level should be
- esp32.wake_on_ext1(pins, level)¶
Configure how EXT1 wakes the device from sleep. pins can be
Noneor a tuple/list of valid Pin objects. level should be
Configure whether non-RTC GPIO pin configuration is retained during deep-sleep mode for held pads. enable should be a boolean value.
Read the raw value of the internal temperature sensor, returning an integer.
Read the raw value of the internal Hall sensor, returning an integer.
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
The capabilities parameter corresponds to ESP-IDF’s
MALLOC_CAP_XXXvalues but the two most useful ones are predefined as
esp32.HEAP_DATAfor data heap regions and
esp32.HEAP_EXECfor 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)]
This class gives access to the partitions in the device’s flash memory and includes methods to enable over-the-air (OTA) updates.
- class esp32.Partition(id, block_size=4096, /)¶
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:
RUNNING. block_size specifies the byte size of an individual block.
- classmethod Partition.find(type=TYPE_APP, subtype=255, label=None, block_size=4096)¶
Find a partition specified by type, subtype and label. Returns a (possibly empty) list of Partition objects. Note:
subtype=0xffmatches any subtype and
label=Nonematches any label.
block_size specifies the byte size of an individual block used by the returned objects.
Returns a 6-tuple
(type, subtype, addr, size, label, encrypted).
- Partition.readblocks(block_num, buf)¶
- Partition.readblocks(block_num, buf, offset)
- Partition.writeblocks(block_num, buf)¶
- Partition.writeblocks(block_num, buf, offset)
- Partition.ioctl(cmd, arg)¶
These methods implement the simple and extended block protocol defined by
Sets the partition as the boot partition.
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_rollbackis 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_rollbackon every boot and it is not necessary when booting firmare that was loaded using esptool.
Used in the
Partitionconstructor to fetch various partitions:
BOOTis the partition that will be booted at the next reset and
RUNNINGis the currently running partition.
Partition.findto specify the partition type:
APPis for bootable firmware partitions (typically labelled
DATAis for other partitions, e.g.
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, idle_level=0) # To apply a carrier frequency to the high output r = esp32.RMT(0, pin=Pin(18), clock_div=8, tx_carrier=(38000, 50, 1)) # The channel resolution is 100ns (1/(source_freq/clock_div)). r.write_pulses((1, 20, 2, 40), 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).
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.
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,
For more details see Espressif’s ESP-IDF RMT documentation..
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 esp32.RMT(channel, *, pin=None, clock_div=8, idle_level=False, tx_carrier=None)¶
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. idle_level specifies what level the output will be when no transmission is in progress and can be any value that converts to a boolean, with
Truerepresenting high voltage and
To enable the transmission carrier feature, tx_carrier should be a tuple of three positive integers: carrier frequency, duty percent (
100) and the output level to apply the carrier to (a boolean as per idle_level).
Returns the source clock frequency. Currently the source clock is not configurable so this will always return 80MHz.
Return the clock divider. Note that the channel resolution is
1 / (source_freq / clock_div).
- RMT.wait_done(*, timeout=0)¶
Trueif the channel is idle or
Falseif a sequence of pulses started with
RMT.write_pulsesis being transmitted. If the timeout keyword argument is given then block for up to this many milliseconds for transmission to complete.
Configure looping on the channel. enable_loop is bool, set to
Trueto enable looping on the next call to
RMT.write_pulses. If called with
Falsewhile a looping sequence is currently being transmitted then the current loop iteration will be completed and then transmission will stop.
- RMT.write_pulses(duration, data=True)¶
Begin transmitting a sequence. There are three ways to specify this:
Mode 1: duration is a list or tuple of durations. The optional data argument specifies the initial output level. The output level will toggle after each duration.
Mode 2: duration is a positive integer and data is a list or tuple of output levels. duration specifies a fixed duration for each.
Mode 3: duration and data are lists or tuples of equal length, specifying individual durations and the output level for each.
Durations are in integer units of the channel resolution (as described above), between 1 and 32767 units. Output levels are any value that can be converted to a boolean, with
Truerepresenting high voltage and
If transmission of an earlier sequence is in progress then this method will block until that transmission is complete before beginning the new sequence.
If looping has been enabled with
RMT.loop, the sequence will be repeated indefinitely. Further calls to this method will block until the end of the current loop iteration before immediately beginning to loop the new sequence of pulses. Looping sequences longer than 126 pulses is not supported by the hardware.
- static RMT.bitstream_channel([value])¶
Select which RMT channel is used by the
machine.bitstreamimplementation. value can be
Noneor a valid RMT channel number. The default RMT channel is the highest numbered one.
Nonedisables the use of RMT and instead selects a bit-banging implementation for
Passing in no argument will not change the channel. This function returns the current channel number.
- class esp32.ULP¶
This class provides access to the Ultra-Low-Power co-processor.
- ULP.set_wakeup_period(period_index, period_us)¶
Set the wake-up period.
- ULP.load_binary(load_addr, program_binary)¶
Load a program_binary into the ULP at the given load_addr.
Start the ULP running at the given entry_point.
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.
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 esp32.NVS(namespace)¶
Create an object providing access to a namespace (which is automatically created if not present).
- NVS.set_i32(key, value)¶
Sets a 32-bit signed integer value for the specified key. Remember to call commit!
Returns the signed integer value for the specified key. Raises an OSError if the key does not exist or has a different type.
- 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!
- 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.
Erases a key-value pair.
Commits changes made by set_xxx methods to flash.