MicroPython on ESP32

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MicroPython on ESP32
Sat 24 Feb 2018 14:00
till Sat 24 Feb 2018 0:00
Micropython.png
What:
Mycropython on ESP32
Tagline:
Let's play with MicroPython on ESP32
Where:
HSBXL Brussels,Belgium
Cost:
NULL, but we have 'Lolin32 lite' boards available for 10€
Who:
Zoobab, U_go
URL:


About

Let' play around with micropython on the ESP32, in our case the 'Lolin32 lite' boards.

MicroPython is a interpreter for the Python language dedicated to Microcontrollers, making easier for everyone to play with microcontrollers.

ESP32 is a new powerful microcontroller with Wifi and Bluetooth on board, perfect to play with the IoT.

Do not forget

  • laptop
  • microusb cable
  • breadboard (optional)
  • leds (optional)
  • arduino modules (optional)

ESP32

The ESP32 is the successor of the ESP8266, with bluetooth, more memory and a higher frequency.

ESP8266 vs ESP32.png

Meeting notes

1. Connect on the serial console

Linux: 

   1. install screen
   2. ls /dev/ttyUSB0
   3. screen /dev/ttyUSB0 115200
   4. you should get a prompt:
   >>> 
   >>> 
   5. you can also use python itself to access the serial console
   $ python -m serial.tools.miniterm /dev/ttyUSB0 115200
   --- Miniterm on /dev/ttyUSB0  115200,8,N,1 ---
   --- Quit: Ctrl+] | Menu: Ctrl+T | Help: Ctrl+T followed by Ctrl+H ---
  >>>

Windows: 

   4. putty: http://store.chipkin.com/articles/using-putty-for-serial-com-connections-hyperterminal-replacement

OSX: use screen as well 

   1. screen /dev/tty.wchusbserial1410 115200

2. Read the help()

>>> help() Welcome to MicroPython on the ESP32!

For generic online docs please visit http://docs.micropython.org/

For access to the hardware use the 'machine' module:impor 

   import machine
   pin12 = machine.Pin(12, machine.Pin.OUT)
   pin12.value(1)
   pin13 = machine.Pin(13, machine.Pin.IN, machine.Pin.PULL_UP)
   print(pin13.value())
   i2c = machine.I2C(scl=machine.Pin(21), sda=machine.Pin(22))
   i2c.scan()
   i2c.writeto(addr, b'1234')
   i2c.readfrom(addr, 4)

Basic WiFi configuration: 

   import network
   sta_if = network.WLAN(network.STA_IF); 
   sta_if.active(True)
   sta_if.scan()                             # Scan for available access points
   sta_if.connect("<AP_name>", "<password>") # Connect to an AP
   sta_if.isconnected()                      # Check for successful connection

Control commands: 

 CTRL-A        -- on a blank line, enter raw REPL mode
 CTRL-B        -- on a blank line, enter normal REPL mode
 CTRL-C        -- interrupt a running program
 CTRL-D        -- on a blank line, do a soft reset of the board
 CTRL-E        -- on a blank line, enter paste mode

For further help on a specific object, type help(obj) For a list of available modules, type help('modules') >>>


3. Identify your version

   >>> import sys
   >>> sys.implementation
   (name='micropython', version=(1, 9, 2))
   >>> sys.version
   '3.4.0'
   >>>

4. Blink the LED (pin22)

   >>> import time
   >>> from machine import Pin
   >>> led=Pin(22,Pin.OUT)
   >>> while True:
       led.value(1)
       time.sleep(0.5)
       led.value(0)
       time.sleep(0.5)

Then you should have the LED blinking...

5. Look at the Quick Reference for ESP8266

This quick reference is for a less-powerful chip from the same company, but most instructions should work the same.

https://docs.micropython.org/en/latest/esp8266/esp8266/quickref.html

6. Try to connect to the WIFI

   >>> import network
   >>> wlan = network.WLAN(network.STA_IF) # create station interface
   >>> wlan.active(True)       # activate the interface
   >>> wlan.scan()             # scan for access points
   >>> wlan.isconnected()      # check if the station is connected to an AP
   >>> wlan.connect('HSBXL', 'CLUBMATE2010') # connect to an AP
   >>> wlan.config('mac')      # get the interface's MAC adddressµ
   >>> wlan.ifconfig()         # get the interface's IP/netmask/gw/DNS addresses
   ('172.23.187.115', '255.255.255.128', '172.23.187.1', '172.23.187.1')
   >>> ap = network.WLAN(network.AP_IF) # create access-point interface
   >>> ap.active(True)         # activate the interface
   I (2892816) wifi: mode : sta (30:ae:a4:4e:84:a8) + softAP (30:ae:a4:4e:84:a9)
   I (2892816) wifi: pm stop, total sleep time: 0/97419646
   True
   I (2892826) wifi: event 13
   ap.config(essid='ESP-AP') # set the ESSID of the access point, you should be able to see this new Wifi network from your laptop...try to ping it from your laptop: $ ping 172.23.187.115

7. Install a package with UPIP

   >>> import upip
   I (3929506) modsocket: Initializing
   >>> upip.install('micropython-telnetlib')
   Installing to: /lib/
   Installing micropython-telnetlib 0.0.1 from https://pypi.python.org/packages/22/0a/ae956d478b893a0d170fc66f781c880249a44fee930fde5f18b440e754c8/micropython-telnetlib-0.0.1.tar.gz

This is just to show that you can install a library, not very useful except to test that you can install something.


8. Upgrade your firmware

Just read the documentation on : https://micropython.org/download

But in brief, pip install esptools --user You will have a esptools.py file in your ~/.local/bin/ directory from the download page, you can find the last version of the firmware for esp32, http://micropython.org/resources/firmware/esp32-20180224-v1.9.3-362-g2ad555bc.bin

before the upgrade, just disconnect your terminal session to the esp32 download it and just apply it with esptools.py

example: 

   esptools.py --chip esp32 --port /dev/ttyUSB0 write_flash -z 0x1000 esp32-20180224-v1.9.3-362-g2ad555bc.bin

get the esptools for python 

   $ sudo apt install python-pip
   $ sudo pip install --upgrade pip
   $ sudo pip install esptool --upgrade

Next, you have to erase the old firmware! 

   $ esptool.py --port /dev/ttyUSB0 erase_flash

Then flash the new firmware: $ esptool.py --chip esp32 --port /dev/ttyUSB0 write_flash -z 0x1000 newfirmware.bin


9. Create a website with picoweb

   >>> import upip
   >>> upip.install('picoweb')
   >>> def index(req, resp):
   ...     yield from resp.awrite('HTTP/1.0 200 OK\r\n')
   ...     yield from resp.awrite('Content-Type: text/html\r\n')
   ...     yield from resp.awrite('\r\n')
   ...     yield from resp.awrite('I can show something to zoobab')
   ...     
   ...     
   ... 
   >>> app = picoweb.WebApp(__name__, [('/', index)])
   >>> app.run(debug=True, host='0.0.0.0')
   * Running on http://0.0.0.0:8081/


10. Use an ESP8266 as a serial adaptor

https://www.cnx-software.com/2017/04/07/transform-your-esp8266-board-into-a-usb-to-serial-board-easily-with-arduino-serial-bypass-sketch/

https://www.cnx-software.com/2017/10/16/esp32-micropython-tutorials/

Registration

We have 20 Lolin32 boards in stock for participants.

Please register here:

https://www.meetup.com/hackerspace-Brussels-hsbxl/events/247897619

Board reservations

Please add your name to the list below if you want us to keep a Lolin32 for you:

  • betz
  • Polyglot
  • Nino
  • George (via Ugo)
  • Blazej (via Ugo)
  • Olivier (D.)
  • Ali (via Ugo)
  • Jacopo (via Ugo)
  • Jason Friel
  • Bob (gratefulfrog)
  • [You ?]

Boards not reserved will be available during the workshop, but first-come first-served ;-)

Notepad

https://etherpad.openstack.org/p/Micropython-esp32

Links

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