Chalmers Robotics Chalmers Robotics

MicroPython

a software implementation of the Python 3 programming language, written in C, that is optimized to run on a microcontroller

https://docs.micropython.org/en/latest/pyboard/

NodeMCU Devkit

• ESP8266 a microcontroller from Espressif
• Integrated WiFi
• 80MHz clock speed

Install

Windows/Mac CP2102 virtual com port driver

If you're running Windows or Mac you may have to install the virtual com port driver.

https://www.silabs.com/products/development-tools/software/usb-to-uart-bridge-vcp-drivers

Firmware

http://docs.micropython.org/en/v1.8.2/esp8266/esp8266/tutorial/intro.html#deploying-the-firmware

http://micropython.org/download#esp8266

wget http://micropython.org/resources/firmware/esp8266-20190125-v1.10.bin
pip install esptool
esptool.py --port /dev/ttyUSB0 write_flash 0 esp8266-20190125-v1.10.bin

Connect through serial

screen /dev/ttyUSB0 115200

Stäng screen: Ctrl+A, k, y

Connect to WiFi

http://docs.micropython.org/en/v1.8.7/esp8266/esp8266/tutorial/network_basics.html

import network
ap_if = network.WLAN(network.AP_IF)
ap_if.disconnect()

sta_if = network.WLAN(network.STA_IF)
sta_if.active(True)

sta_if.connect('SSID', 'password')

sta_if.ifconfig()

HTTP GET

import urequests
response = urequests.get("http://tim.gremalm.se/hello")
response.text
response.close()

Connect through WEBrepl (websocket)

https://learn.adafruit.com/micropython-basics-esp8266-webrepl/access-webrepl

import webrepl_setup

Use HTTP and not HTTPS when connecting to the websocket. HTTPS-version doesn't support connecting to HTTP websocket due to mixed content. http://micropython.org/webrepl/

GPIO

https://docs.micropython.org/en/latest/esp8266/esp8266/tutorial/pins.html

from machine import Pin
button = Pin(0)
button = Pin(0, Pin.IN, Pin.PULL_UP)
pin.value()

[1]

WS2812

http://docs.micropython.org/en/v1.8.2/esp8266/esp8266/tutorial/neopixel.html

from machine import Pin
from neopixel import NeoPixel

np = NeoPixel(Pin(2), 3)

np[0] = (255, 0, 0)
np[1] = (0, 128, 0)
np[2] = (0, 0, 64)
np.write()

Color conversion with HSL2GRB

https://gist.github.com/dries007/26a2f36770c28500b912b0ecf1276129 Makes it easier to work with colors. Send in argument hue, and get out RGB

def hsv_to_rgb(h, s, v):
	if s == 0.0:
		return v, v, v
	i = int(h*6.0)
	f = (h*6.0) - i
	p = v*(1.0 - s)
	q = v*(1.0 - s*f)
	t = v*(1.0 - s*(1.0-f))
	i = i%6
	if i == 0:
		return v, t, p
	if i == 1:
		return q, v, p
	if i == 2:
		return p, v, t
	if i == 3:
		return p, q, v
	if i == 4:
		return t, p, v
	if i == 5:
		return v, p, q

Servo

Download and upload to ESP's flash: https://github.com/TimGremalm/Folkrace187/blob/master/servo.py

servoA = servo.Servo(machine.Pin(14))
servoA.write_angle(90)
time.sleep(1)
servoA.write_angle(110)

File system on flash

import os
os.listdir()
os.remove('filename')

ampy

https://github.com/adafruit/ampy

a file utility tool for MicroPython on ESP8266