diff options
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/esp8266/general.rst | 11 | ||||
| -rw-r--r-- | docs/esp8266/tutorial/intro.rst | 23 | ||||
| -rw-r--r-- | docs/esp8266/tutorial/network_tcp.rst | 1 | ||||
| -rw-r--r-- | docs/library/esp.rst | 36 | ||||
| -rw-r--r-- | docs/library/index.rst | 23 | ||||
| -rw-r--r-- | docs/library/machine.I2C.rst | 59 | ||||
| -rw-r--r-- | docs/library/machine.UART.rst | 11 | ||||
| -rw-r--r-- | docs/library/pyb.Accel.rst | 8 | ||||
| -rw-r--r-- | docs/library/pyb.I2C.rst | 5 | ||||
| -rw-r--r-- | docs/library/pyb.UART.rst | 27 | ||||
| -rw-r--r-- | docs/library/pyb.USB_VCP.rst | 10 | ||||
| -rw-r--r-- | docs/library/usocket.rst | 18 |
12 files changed, 160 insertions, 72 deletions
diff --git a/docs/esp8266/general.rst b/docs/esp8266/general.rst index 04afed46e..cd659f80a 100644 --- a/docs/esp8266/general.rst +++ b/docs/esp8266/general.rst @@ -58,6 +58,17 @@ For your convenience, some of technical specifications are provided below: and always-available BootROM bootloader, ESP8266 is not brickable. +Scarcity of runtime resources +----------------------------- + +ESP8266 has very modest resources (first of all, RAM memory). So, please +avoid allocating too big container objects (lists, dictionaries) and +buffers. There is also no full-fledged OS to keep track of resources +and automatically clean them up, so that's the task of a user/user +application: please be sure to close open files, sockets, etc. as soon +as possible after use. + + Boot process ------------ diff --git a/docs/esp8266/tutorial/intro.rst b/docs/esp8266/tutorial/intro.rst index 87d446340..fe824cfff 100644 --- a/docs/esp8266/tutorial/intro.rst +++ b/docs/esp8266/tutorial/intro.rst @@ -35,11 +35,30 @@ If your board has a USB connector on it then most likely it is powered through this when connected to your PC. Otherwise you will need to power it directly. Please refer to the documentation for your board for further details. +Getting the firmware +-------------------- + +The first thing you need to do is download the most recent MicroPython firmware +.bin file to load onto your ESP8266 device. You can download it from the +`MicroPython downloads page <http://micropython.org/download#esp8266>`_. +From here, you have 3 main choices + +* Stable firmware builds for 1024kb modules and above. +* Daily firmware builds for 1024kb modules and above. +* Daily firmware builds for 512kb modules. + +The best bet is nearly always to go for the Stable firmware builds. +An exception to this though is if you have an ESP8266 module with only 512kb +of onboard storage. You can easily tell by trying to load a Stable firmware +build and if you get the error below, then you may have to use the Daily +firmware builds for 512kb modules. + WARNING: Unlikely to work as data goes beyond end of flash. + Deploying the firmware ---------------------- -The very first thing you need to do is put the MicroPython firmware (compiled -code) on your ESP8266 device. There are two main steps to do this: first you +Once you have the MicroPython firmware (compiled code), you need to load it onto +your ESP8266 device. There are two main steps to do this: first you need to put your device in boot-loader mode, and second you need to copy across the firmware. The exact procedure for these steps is highly dependent on the particular board and you will need to refer to its documentation for details. diff --git a/docs/esp8266/tutorial/network_tcp.rst b/docs/esp8266/tutorial/network_tcp.rst index 80a494721..26a2f469c 100644 --- a/docs/esp8266/tutorial/network_tcp.rst +++ b/docs/esp8266/tutorial/network_tcp.rst @@ -72,6 +72,7 @@ Let's define a function that can download and print a URL:: print(str(data, 'utf8'), end='') else: break + s.close() Make sure that you import the socket module before running this function. Then you can try:: diff --git a/docs/library/esp.rst b/docs/library/esp.rst index 0836bba72..8cafb92cd 100644 --- a/docs/library/esp.rst +++ b/docs/library/esp.rst @@ -45,3 +45,39 @@ Functions .. function:: flash_write(byte_offset, bytes) .. function:: flash_erase(sector_no) + +.. function:: set_native_code_location(start, length) + + Set the location that native code will be placed for execution after it is + compiled. Native code is emitted when the ``@micropython.native``, + ``@micropython.viper`` and ``@micropython.asm_xtensa`` decorators are applied + to a function. The ESP8266 must execute code from either iRAM or the lower + 1MByte of flash (which is memory mapped), and this function controls the + location. + + If `start` and `length` are both `None` then the native code location is + set to the unused portion of memory at the end of the iRAM1 region. The + size of this unused portion depends on the firmware and is typically quite + small (around 500 bytes), and is enough to store a few very small + functions. The advantage of using this iRAM1 region is that it does not + get worn out by writing to it. + + If neither `start` nor `length` are `None` then they should be integers. + `start` should specify the byte offset from the beginning of the flash at + which native code should be stored. `length` specifies how many bytes of + flash from `start` can be used to store native code. `start` and `length` + should be multiples of the sector size (being 4096 bytes). The flash will + be automatically erased before writing to it so be sure to use a region of + flash that is not otherwise used, for example by the firmware or the + filesystem. + + When using the flash to store native code `start+length` must be less + than or equal to 1MByte. Note that the flash can be worn out if repeated + erasures (and writes) are made so use this feature sparingly. + In particular, native code needs to be recompiled and rewritten to flash + on each boot (including wake from deepsleep). + + In both cases above, using iRAM1 or flash, if there is no more room left + in the specified region then the use of a native decorator on a function + will lead to `MemoryError` exception being raised during compilation of + that function. diff --git a/docs/library/index.rst b/docs/library/index.rst index 1619be498..8ee19a98e 100644 --- a/docs/library/index.rst +++ b/docs/library/index.rst @@ -36,15 +36,20 @@ Python standard libraries and micro-libraries The following standard Python libraries have been "micro-ified" to fit in with the philosophy of MicroPython. They provide the core functionality of that module and are intended to be a drop-in replacement for the standard Python -library. - -.. only:: not port_unix - - The modules are available by their u-name, and also by their non-u-name. The - non-u-name can be overridden by a file of that name in your package path. - For example, ``import json`` will first search for a file ``json.py`` or - directory ``json`` and load that package if it is found. If nothing is found, - it will fallback to loading the built-in ``ujson`` module. +library. Some modules below use a standard Python name, but prefixed with "u", +e.g. ``ujson`` instead of ``json``. This is to signify that such a module is +micro-library, i.e. implements only a subset of CPython module functionality. +By naming them differently, a user has a choice to write a Python-level module +to extend functionality for better compatibility with CPython (indeed, this is +what done by micropython-lib project mentioned above). + +On some embedded platforms, where it may be cumbersome to add Python-level +wrapper modules to achieve naming compatibility with CPython, micro-modules +are available both by their u-name, and also by their non-u-name. The +non-u-name can be overridden by a file of that name in your package path. +For example, ``import json`` will first search for a file ``json.py`` or +directory ``json`` and load that package if it is found. If nothing is found, +it will fallback to loading the built-in ``ujson`` module. .. only:: port_unix diff --git a/docs/library/machine.I2C.rst b/docs/library/machine.I2C.rst index f5820f103..cdeb246eb 100644 --- a/docs/library/machine.I2C.rst +++ b/docs/library/machine.I2C.rst @@ -49,12 +49,23 @@ Constructors Construct an I2C object on the given bus. `bus` can only be 0. If the bus is not given, the default one will be selected (0). -.. only:: port_esp8266 +.. only:: not port_wipy + + .. class:: I2C(id=-1, \*, scl, sda, freq=400000) - .. class:: I2C(scl, sda, \*, freq=400000) + Construct and return a new I2C object using the following parameters: - Construct and return a new I2C object. - See the init method below for a description of the arguments. + - `id` identifies the particular I2C peripheral. The default + value of -1 selects a software implementation of I2C which can + work (in most cases) with arbitrary pins for SCL and SDA. + If `id` is -1 then `scl` and `sda` must be specified. Other + allowed values for `id` depend on the particular port/board, + and specifying `scl` and `sda` may or may not be required or + allowed in this case. + - `scl` should be a pin object specifying the pin to use for SCL. + - `sda` should be a pin object specifying the pin to use for SDA. + - `freq` should be an integer which sets the maximum frequency + for SCL. General Methods --------------- @@ -102,29 +113,31 @@ control over the bus, otherwise the standard methods (see below) can be used. .. method:: I2C.start() - Send a start bit on the bus (SDA transitions to low while SCL is high). + Generate a START condition on the bus (SDA transitions to low while SCL is high). Availability: ESP8266. .. method:: I2C.stop() - Send a stop bit on the bus (SDA transitions to high while SCL is high). + Generate a STOP condition on the bus (SDA transitions to high while SCL is high). Availability: ESP8266. -.. method:: I2C.readinto(buf) +.. method:: I2C.readinto(buf, nack=True) Reads bytes from the bus and stores them into `buf`. The number of bytes read is the length of `buf`. An ACK will be sent on the bus after - receiving all but the last byte, and a NACK will be sent following the last - byte. + receiving all but the last byte. After the last byte is received, if `nack` + is true then a NACK will be sent, otherwise an ACK will be sent (and in this + case the slave assumes more bytes are going to be read in a later call). Availability: ESP8266. .. method:: I2C.write(buf) - Write all the bytes from `buf` to the bus. Checks that an ACK is received - after each byte and raises an OSError if not. + Write the bytes from `buf` to the bus. Checks that an ACK is received + after each byte and stops transmitting the remaining bytes if a NACK is + received. The function returns the number of ACKs that were received. Availability: ESP8266. @@ -134,29 +147,27 @@ Standard bus operations The following methods implement the standard I2C master read and write operations that target a given slave device. -.. method:: I2C.readfrom(addr, nbytes) +.. method:: I2C.readfrom(addr, nbytes, stop=True) Read `nbytes` from the slave specified by `addr`. + If `stop` is true then a STOP condition is generated at the end of the transfer. Returns a `bytes` object with the data read. -.. method:: I2C.readfrom_into(addr, buf) +.. method:: I2C.readfrom_into(addr, buf, stop=True) Read into `buf` from the slave specified by `addr`. The number of bytes read will be the length of `buf`. + If `stop` is true then a STOP condition is generated at the end of the transfer. - On WiPy the return value is the number of bytes read. Otherwise the - return value is `None`. - -.. method:: I2C.writeto(addr, buf, \*, stop=True) - - Write the bytes from `buf` to the slave specified by `addr`. + The method returns `None`. - The `stop` argument (only available on WiPy) tells if a stop bit should be - sent at the end of the transfer. If `False` the transfer should be - continued later on. +.. method:: I2C.writeto(addr, buf, stop=True) - On WiPy the return value is the number of bytes written. Otherwise the - return value is `None`. + Write the bytes from `buf` to the slave specified by `addr`. If a + NACK is received following the write of a byte from `buf` then the + remaining bytes are not sent. If `stop` is true then a STOP condition is + generated at the end of the transfer, even if a NACK is received. + The function returns the number of ACKs that were received. Memory operations ----------------- diff --git a/docs/library/machine.UART.rst b/docs/library/machine.UART.rst index f832cf466..0b6b24e89 100644 --- a/docs/library/machine.UART.rst +++ b/docs/library/machine.UART.rst @@ -31,7 +31,7 @@ A UART object acts like a stream object and reading and writing is done using the standard stream methods:: uart.read(10) # read 10 characters, returns a bytes object - uart.readall() # read all available characters + uart.read() # read all available characters uart.readline() # read a line uart.readinto(buf) # read and store into the given buffer uart.write('abc') # write the 3 characters @@ -95,17 +95,12 @@ Methods .. method:: UART.read([nbytes]) - Read characters. If ``nbytes`` is specified then read at most that many bytes. + Read characters. If ``nbytes`` is specified then read at most that many bytes, + otherwise read as much data as possible. Return value: a bytes object containing the bytes read in. Returns ``None`` on timeout. -.. method:: UART.readall() - - Read as much data as possible. - - Return value: a bytes object or ``None`` on timeout. - .. method:: UART.readinto(buf[, nbytes]) Read bytes into the ``buf``. If ``nbytes`` is specified then read at most diff --git a/docs/library/pyb.Accel.rst b/docs/library/pyb.Accel.rst index 2ae357fe7..061996485 100644 --- a/docs/library/pyb.Accel.rst +++ b/docs/library/pyb.Accel.rst @@ -46,3 +46,11 @@ Methods .. method:: Accel.z() Get the z-axis value. + +Hardware Note +------------- + +The accelerometer uses I2C bus 1 to communicate with the processor. Consequently +when readings are being taken pins X9 and X10 should be unused (other than for +I2C). Other devices using those pins, and which therefore cannot be used +concurrently, are UART 1 and Timer 4 channels 1 and 2. diff --git a/docs/library/pyb.I2C.rst b/docs/library/pyb.I2C.rst index 67131feec..740031890 100644 --- a/docs/library/pyb.I2C.rst +++ b/docs/library/pyb.I2C.rst @@ -92,7 +92,7 @@ Methods .. only:: port_pyboard - .. method:: I2C.init(mode, \*, addr=0x12, baudrate=400000, gencall=False) + .. method:: I2C.init(mode, \*, addr=0x12, baudrate=400000, gencall=False, dma=False) Initialise the I2C bus with the given parameters: @@ -100,6 +100,9 @@ Methods - ``addr`` is the 7-bit address (only sensible for a slave) - ``baudrate`` is the SCL clock rate (only sensible for a master) - ``gencall`` is whether to support general call mode + - ``dma`` is whether to allow the use of DMA for the I2C transfers (note + that DMA transfers have more precise timing but currently do not handle bus + errors properly) .. method:: I2C.is_ready(addr) diff --git a/docs/library/pyb.UART.rst b/docs/library/pyb.UART.rst index 4a692469f..76f347ffa 100644 --- a/docs/library/pyb.UART.rst +++ b/docs/library/pyb.UART.rst @@ -27,7 +27,7 @@ A UART object acts like a stream object and reading and writing is done using the standard stream methods:: uart.read(10) # read 10 characters, returns a bytes object - uart.readall() # read all available characters + uart.read() # read all available characters uart.readline() # read a line uart.readinto(buf) # read and store into the given buffer uart.write('abc') # write the 3 characters @@ -87,8 +87,8 @@ Methods - ``stop`` is the number of stop bits, 1 or 2. - ``flow`` sets the flow control type. Can be 0, ``UART.RTS``, ``UART.CTS`` or ``UART.RTS | UART.CTS``. - - ``timeout`` is the timeout in milliseconds to wait for the first character. - - ``timeout_char`` is the timeout in milliseconds to wait between characters. + - ``timeout`` is the timeout in milliseconds to wait for writing/reading the first character. + - ``timeout_char`` is the timeout in milliseconds to wait between characters while writing or reading. - ``read_buf_len`` is the character length of the read buffer (0 to disable). This method will raise an exception if the baudrate could not be set within @@ -111,17 +111,15 @@ Methods Returns the number of bytes waiting (may be 0). - .. method:: UART.writechar(char) - - Write a single character on the bus. ``char`` is an integer to write. - Return value: ``None``. See note below if CTS flow control is used. - .. method:: UART.read([nbytes]) Read characters. If ``nbytes`` is specified then read at most that many bytes. If ``nbytes`` are available in the buffer, returns immediately, otherwise returns when sufficient characters arrive or the timeout elapses. + If ``nbytes`` is not given then the method reads as much data as possible. It + returns after the timeout has elapsed. + .. only:: port_pyboard *Note:* for 9 bit characters each character takes two bytes, ``nbytes`` must @@ -130,12 +128,6 @@ Methods Return value: a bytes object containing the bytes read in. Returns ``None`` on timeout. -.. method:: UART.readall() - - Read as much data as possible. Returns after the timeout has elapsed. - - Return value: a bytes object or ``None`` if timeout prevents any data being read. - .. method:: UART.readchar() Receive a single character on the bus. @@ -170,6 +162,13 @@ Methods Return value: number of bytes written. If a timeout occurs and no bytes were written returns ``None``. +.. only:: port_pyboard + + .. method:: UART.writechar(char) + + Write a single character on the bus. ``char`` is an integer to write. + Return value: ``None``. See note below if CTS flow control is used. + .. method:: UART.sendbreak() Send a break condition on the bus. This drives the bus low for a duration diff --git a/docs/library/pyb.USB_VCP.rst b/docs/library/pyb.USB_VCP.rst index 4e34af258..4c4fe4516 100644 --- a/docs/library/pyb.USB_VCP.rst +++ b/docs/library/pyb.USB_VCP.rst @@ -44,16 +44,12 @@ Methods .. method:: USB_VCP.read([nbytes]) Read at most ``nbytes`` from the serial device and return them as a - bytes object. If ``nbytes`` is not specified then the method acts as - ``readall()``. USB_VCP stream implicitly works in non-blocking mode, + bytes object. If ``nbytes`` is not specified then the method reads + all available bytes from the serial device. + USB_VCP stream implicitly works in non-blocking mode, so if no pending data available, this method will return immediately with ``None`` value. -.. method:: USB_VCP.readall() - - Read all available bytes from the serial device and return them as - a bytes object, or ``None`` if no pending data available. - .. method:: USB_VCP.readinto(buf, [maxlen]) Read bytes from the serial device and store them into ``buf``, which diff --git a/docs/library/usocket.rst b/docs/library/usocket.rst index 9b279e5ba..c46e8f4c5 100644 --- a/docs/library/usocket.rst +++ b/docs/library/usocket.rst @@ -149,10 +149,18 @@ Methods Set a timeout on blocking socket operations. The value argument can be a nonnegative floating point number expressing seconds, or None. If a non-zero value is given, subsequent socket operations - will raise a timeout exception if the timeout period value has elapsed before the operation has + will raise an ``OSError`` exception if the timeout period value has elapsed before the operation has completed. If zero is given, the socket is put in non-blocking mode. If None is given, the socket is put in blocking mode. + .. admonition:: Difference to CPython + :class: attention + + CPython raises a ``socket.timeout`` exception in case of timeout, + which is an ``OSError`` subclass. MicroPython raises an OSError directly + instead. If you use ``except OSError:`` to catch the exception, + your code will work both in MicroPython and CPython. + .. method:: socket.setblocking(flag) Set blocking or non-blocking mode of the socket: if flag is false, the socket is set to non-blocking, @@ -178,14 +186,10 @@ Methods Closing the file object returned by makefile() WILL close the original socket as well. - .. method:: socket.read(size) + .. method:: socket.read([size]) Read up to size bytes from the socket. Return a bytes object. If ``size`` is not given, it - behaves just like ``socket.readall()``, see below. - - .. method:: socket.readall() - - Read all data available from the socket until ``EOF``. This function will not return until + reads all data available from the socket until ``EOF``; as such the method will not return until the socket is closed. .. method:: socket.readinto(buf[, nbytes]) |