Chao at 17:30, 21 October 2019

2019-10-21T17:30:43Z

New page

== ESP8266 ==
* Official github page: https://github.com/micropython/micropython/tree/master/esp8266

=== Demo code ===
* GPIO Access
<syntaxhighlight lang="python">
>>> import pyb
>>> pin = pyb.Pin(14, pyb.Pin.OUT_PP) # Set pin 14 as an output.
>>> for i in range(10):
... pin.value(0) # Set pin low (or use pin.low())
... pyb.delay(1000) # Delay for 1000ms (1 second)
... pin.value(1) # Set pin high (or use pin.high())
... pyb.delay(1000)
</syntaxhighlight>
* Reading GPIO Input
<syntaxhighlight lang="python">
>>> import pyb
>>> pin = pyb.Pin(14, pyb.Pin.IN)
>>> pin.value() # Read pin value, will show 0 when low (connected to ground).
0
>>> pin.value() # Read pin value again, will show 1 when high (connected to 3.3V).
1
</syntaxhighlight>
* Wifi Setup
<syntaxhighlight lang="python">
>>> import esp
>>>
>>> # Connect to a WiFi network.
>>> esp.connect('YOUR WIFI SSID NAME', 'YOUR WIFI SSID PASSWORD')
>>>
>>> # Define function to print data received from socket.
>>> def socket_printer(socket, data):
>>> print(data)
>>>
>>> # Create a socket and setup the print function.
>>> soc = esp.socket()
>>> soc.onrecv(socket_printer)
>>>
>>> # Connect to adafruit.com at port 80.
>>> soc.connect(('207.58.139.247', 80))
>>>
>>> # Send a request for the wifi test page.
>>> soc.send('GET /testwifi/index.html HTTP/1.0\r\n\r\n')
37
>>> b'HTTP/1.1 200 OK\r\nDate: Tue, 12 May 2015 18:44:49 GMT\r\nServer: Apache\r\nAccess-Control-Allow-Headers: Origin, X-Requested-With, Content-Type, Accept, Accept-Encoding, Authorization, Referer, User-Agent\r\nAccess-Control-Allow-Methods: GET, POST, OPTIONS\r\nAccess-Control-Allow-Credentials: true\r\nAccess-Control-Max-Age: 1728000\r\nAccept-Ranges: bytes\r\nX-Mod-Pagespeed: 1.9.32.3-4448\r\nVary: Accept-Encoding\r\nCache-Control: max-age=0, no-cache\r\nContent-Length: 74\r\nConnection: close\r\nContent-Type: text/html\r\n\r\nThis is a test of the CC3000 module!\nIf you can read this, its working :)\n'
</syntaxhighlight>
* If you're curious what other functions exist on the esp.socket class (or any other object in MicroPython) you can see them by using the dir function:
>>> dir(esp.socket)
['__del__', 'close', 'bind', 'listen', 'accept', 'connect', 'send', 'recv', 'sendto', 'recvfrom', 'onconnect', 'onrecv', 'onsent', 'ondisconnect']
* Once connected you can start entering MicroPython code in a '''read-eval-print loop (REPL)'''. For example here's the classic Hello World and counting to 10:
<syntaxhighlight lang="python">
>>> print("Hello world!")
Hello world!
>>> for i in range(1, 11):
... print("Number {0}".format(i))
...
Number 1
Number 2
Number 3
Number 4
Number 5
Number 6
Number 7
Number 8
Number 9
Number 10
>>>
</syntaxhighlight>
=== Usage of esp class ===
import esp
Imports the ESP8266 module.

esp.scan(print)
Scans for visible SSIDs. The argument "print" is the callback method receiving tuples which do describe the found SSIDs.

esp.connect('<ssid>', 'pre-shared-key')
Connects to the given network.

esp.disconnect()
=== Build firmware ===
* Follow the [[ESP8266 Open SDK]] page to completely setup the environment and compile the SDK first

=== Compile the firmware ===
cd ~/micropython/esp8266
make
And the final result should look like below:
<syntaxhighlight lang="text">
LINK build/firmware.elf
text data bss dec hex filename
304096 1332 53776 359204 57b24 build/firmware.elf
Create build/firmware-combined.bin
('flash ', 52800)
('padding ', 12736)
('irom0text', 252672)
('total ', 318208)
</syntaxhighlight>
And finally copy the firmware out to vagrant folder
cp ./build/firmware-combined.bin /vagrant/
=== write the blink LED on main.py ===
turn on the vagrant machine and edit the main.py file:
cd ~/micropython/esp8266/scripts/
nano main.py
<syntaxhighlight lang="python">
# This script is run on boot
import pyb
pin = pyb.Pin(14, pyb.Pin.OUT_PP)
while True:
pin.value(1)
pyb.delay(1000)
pin.value(0)
pyb.delay(1000)
</syntaxhighlight>
and finally make the firmware:
cd ~/micropython/esp8266
make

== Documents ==

ESP8266
* http://docs.micropython.org/en/latest/library/esp.html
* http://docs.micropython.org/en/latest/library/esp.socket.html
[[category: Micropython]]

MP-ESP8266 - Revision history

Chao at 17:30, 21 October 2019