A Hands-on-Introduction to MicroPython
Table of Contents
This chapter will provide a brief overview of MicroPython.
MicroPython: The Embedded Code Knight Rises
MicroPython is essentially Python on Keto diet. It is a lean and efficient implementation of Python, geared towards programming the embedded systems. MicroPython wields a selective arsenal, a subset of Python libraries which are required to perform necessary tasks on constrained devices.
The credit for making your life easier goes to the Damien George, who developed MicroPython in 2013. The idea was to bring the high level programming language to embedded systems developers.
The Story of LK
In the bustling metropolis of Leeds City, there exists a remarkable superhero known as LK, whose extraordinary abilities lie not in super strength or flight, but in the realm of coding and technological ingenuity. LK, whose identity remains shrouded in mystery, harnesses the power of programming to craft ingenious gadgets and tools to combat crime and protect the citizens of Leeds. Armed with a brilliant mind and an arsenal of high-tech gadgets, LK navigates the city’s streets with unparalleled precision, using coding as their superpower to outwit even the most cunning adversaries. Whether it’s hacking into security systems, constructing intricate devices on the fly, or analyzing data to anticipate criminal activity, LK’s coding prowess knows no bounds. With each keystroke, they weave a digital tapestry of justice, ensuring that Leeds City remains safe from harm.
Throughout the rest of the labs, we will be trying to trace his steps and replicate some gadgets from his arsenal.
LK’s early days
So the very first program every programmer needs to learn to write is for printing “Hello world!”. This seems to be an obsession. Why is this the case? Well there is a Wikipedia article describing this (See here) but then again LK was unconventional. His first programming stint included creating a light show on a embedded board. Luckily, you have got the same board. He started with flashing LEDs connected with GPIO0-GPI04 in a sequence. Each LED toggled from high to low after 100 ms. Your mission, if you choose to accept is replicating his steps. Before you embark on this task go through the MicroPython Beginner’s Guide.
Ok, now we know fair amount of the basic stuff. Next up, its time for disco lights . Literally, I mean that. On the board you have been given. There are two Neo-Pixel LEDs. These can create cool Neon like effect. These LED’s are addressable LEDs, i.e. both are connected to same pin but numbered 0,1 and so on. These addressable LEDs allow using single pin to control the entire strip. Let us have a play with these by trying following snippet:
#import neopixel module
import machine, neopixel
np = neopixel.NeoPixel(machine.Pin(18), 2) #NeoPixel is connected to Pin 18 and there are two numbered zero and one on the board
#set color for neopixel
np[0] = (255, 0, 0)
np[1] = (0, 0,255)
#update the color
np.write()
Task 1
LK was big light show fan. Your task is to create a color palette of your choice comprised of three colors for each LED(see https://www.imgonline.com.ua/eng/color-palette.php or if this website is dead just use color picker in your Paint program to find RGB value for a color). Then create a show which blinks these Neo-Pixel's one after another.Inventing LK’s Communication System
As LK grew up, he realised that this example was not much useful. Inspired by the Batman who used to merely flash his logo in the sky to enable one bit communication, the LK thought of something even more cool. May be his fondness of light-show can now turn in to creating a viable wireless communication system. A very primitive one yet a powerful example. He realised he can implement Morse Code by flashing the lights on the board. Therefore, implemented a system where any message provided by him could be transformed into Morse Code. He then started broadcasting these flashes to his friend who has smart phone with an app for decoding these messages.
Task 2
Your final mission today, if you choose to accept it, is implementing Morse code generator using the NeoPixel LEDs on the board. Store a message to be transmitted in some variable and then convert this message into Morse Code.
If you need help, try completing skeleton code below:
import machine, neopixel
import time
np = neopixel.NeoPixel(machine.Pin(18), 2) #NeoPixel is connected to Pin 18 and there are two numbered zero and one on the board
#declare a dictionary which has mapping between characters and code
CODE = {'A':'.-','B':'-...',....}
#declare a color for NeoPixel for On color
color1=...
#declar off color
color2=...
def flashNeo(t):
#write a function to flash NeoPixel for t sec
return
message = "Hello World"
def send():
#Use international standard for on/off times for dash, dot, space and word ends
tdot= 0.12 #sec
tdash = tdot * 3
tspace = tdot * 3
tword = tdot * 7
#write code to make sure NeoPixel is Off
for l in message:
#l will now be a letter
c = #get the corresponding code
for e in c:
#e will be characters in code
if #write code to check what is the character
#blink the NeoPixel
time.sleep(tdot)
#repeat above block to check for dash dot and end of word
time.sleep(tword)
np[0]=color2
np[1]=color2
np.write()
while True:
send()
time.sleep(1)
Something to try
Next up, look up for the data sheet and schematic of the board. Find out how to play tunes on built in buzzer. Then why not try and program the buzzer to play morse code tune.If you want to check wether your Morse Code can be decoded correctly then download a Morse Code Engineer App on your smart phone and use camera to watch the decoded output.