2016-04-20 18:02:48 -04:00
|
|
|
General information about the ESP8266 port
|
|
|
|
|
==========================================
|
|
|
|
|
|
|
|
|
|
ESP8266 is a popular WiFi-enabled System-on-Chip (SoC) by Espressif Systems.
|
|
|
|
|
|
|
|
|
|
Multitude of boards
|
|
|
|
|
-------------------
|
|
|
|
|
|
|
|
|
|
There are multitude of modules and boards from different sources which carry
|
|
|
|
|
ESP8266 chip. MicroPython tries to provide a generic port which would run on
|
|
|
|
|
as many boards/modules as possible, but there may be limitations. Adafruit
|
|
|
|
|
Feather HUZZAH board is taken as a reference board for the port (for example,
|
2016-05-02 09:00:44 -04:00
|
|
|
testing is performed on it). If you have another board, please make sure you
|
|
|
|
|
have datasheet, schematics and other reference materials for your board
|
|
|
|
|
handy to look up various aspects of your board functioning.
|
|
|
|
|
|
|
|
|
|
To make a generic ESP8266 port and support as many boards as possible,
|
|
|
|
|
following design and implementation decision were made:
|
|
|
|
|
|
|
|
|
|
* GPIO pin numbering is based on ESP8266 chip numbering, not some "logical"
|
2016-05-02 09:10:48 -04:00
|
|
|
numbering of a particular board. Please have manual/pin diagram of your board
|
|
|
|
|
handy to find correspondce between your board pins and actual ESP8266 pins.
|
|
|
|
|
We also encourage users of various boards to share this mapping via MicroPython
|
|
|
|
|
forum, with the idea to collect community-maintained reference materials
|
|
|
|
|
eventually.
|
2016-05-02 09:00:44 -04:00
|
|
|
* All pins which make sense to support, are supported by MicroPython
|
2016-05-02 09:10:48 -04:00
|
|
|
(for example, we don't expose pins which are used to connect SPI flash
|
|
|
|
|
are not exposed, as they're unlikely useful for anything else, and
|
|
|
|
|
operating on them will lead to board lock-up). However, any particular
|
|
|
|
|
board may expose only subset of pins. Consult your board reference manual.
|
2016-05-02 09:00:44 -04:00
|
|
|
* Some boards may lack external pins/internal connectivity to support
|
2016-05-02 09:10:48 -04:00
|
|
|
ESP8266 deepsleep mode.
|
2016-05-02 10:12:25 -04:00
|
|
|
|
|
|
|
|
|
|
|
|
|
Technical specifications and SoC datasheets
|
|
|
|
|
-------------------------------------------
|
|
|
|
|
|
|
|
|
|
The datasheets and other reference material for ESP8266 chip are available
|
|
|
|
|
from the vendor site: http://bbs.espressif.com/viewtopic.php?f=67&t=225 .
|
|
|
|
|
The are primary reference for the chip technical specifications, capabilities,
|
|
|
|
|
operating modes, internal functioning, etc.
|
|
|
|
|
|
|
|
|
|
For your convinience, some of technical specifications are provided below:
|
|
|
|
|
|
|
|
|
|
* Architecture: Xtensa lx106
|
|
|
|
|
* CPU frequency: 80MHz overclockable to 160MHz
|
|
|
|
|
* Total RAM available: 96KB (part of it reserved for system)
|
|
|
|
|
* BootROM: 64KB
|
|
|
|
|
* Internal FlashROM: None
|
|
|
|
|
* External FlashROM: code and data, via SPI Flash. Normal sizes 512KB-4MB.
|
|
|
|
|
* GPIO: 16 + 1 (GPIOs are multiplexed with other functions, including
|
|
|
|
|
external FlashROM, UART, deep sleep wake-up, etc.)
|
|
|
|
|
* UART: One RX/TX UART (no hardware handshaking), one TX-only UART.
|
|
|
|
|
* SPI: 2 SPI interfaces (one used for FlashROM).
|
|
|
|
|
* I2C: No native extenal I2C (bitbang implementation available on any pins).
|
|
|
|
|
* I2S: 1.
|
|
|
|
|
* Programming: using BootROM bootloader from UART. Due to external FlashROM
|
|
|
|
|
and always-available BootROM bootloader, ESP8266 is not brickable.
|
