CodingPirates/microbit-micropython-cookbook
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@@ -43,19 +43,25 @@ dir(microbit)
## Some Lesser Known Facts
Since both Python and MicroPython are interpreted languages, they eat a lot of memory. Also, the hex file generated by micro:bit Python editors are consisted of 2 parts: the MicroPython firmware (up to 248 KB) and user's script (up to only 8 KB). See [Firmware Hex File](https://microbit-micropython.readthedocs.io/en/latest/devguide/hexformat.html). Which means it's less likely to build bigger projects with micro:bit's MicroPython.
Since MicroPython, like standard Python, is a interpreted language, it eats a lot of memory. A slightly bigger program may cause MemoryError (out of memory). Also due to this reason, there is no room for the Bluetooth driver.
Another limit is that the MicroPython hex file are consisted of 2 parts: the MicroPython firmware (up to 248 KB) and user's script (up to only 8 KB). See [Firmware Hex File](https://microbit-micropython.readthedocs.io/en/latest/devguide/hexformat.html). Which means it's less likely to build bigger projects with micro:bit's MicroPython.
One way to "minimize" your script size is to use 1-space indents instead of 4.
micro:bit's MicroPython is based on Python 3.4. Which means many built-in Python advanced feaetures, like string.format(), list comprehension, list slice, variable unpacking, lambda function, decorators, generators, @classmethod, @staticmethod, etc. can be used as well.
micro:bit's MicroPython is based on Python 3.4. Which means many built-in Python advanced feaetures are supported. Although some features are dropped as well to save memory.
Also, about how micro:bit get its own version of MicroPython: [The Story of MicroPython on the BBC micro:bit](http://ntoll.org/article/story-micropython-on-microbit) by Nicholas H. Tollervey, who also created the [Mu editor](https://codewith.mu/).
Nicholas H. Tollervey - also the creator of [Mu editor](https://codewith.mu/) - has an interesting account about [How BBC micro:bit get its MicroPython](http://ntoll.org/article/story-micropython-on-microbit).
## Recursion is Not Welcomed
## Editor of Choice
Since micro:bit has very limited memory, the recursion depth is severely limited. Only [8 nested function calls or so](https://mail.python.org/pipermail/microbit/2016-February/000896.html) can be used without triggering RuntimeError.
The official [Python online editor](https://python.microbit.org/v/2.0) does not need installation and can be used anywhere with Internet and Chrome web browser. Support Web-USB. It's ok to use, really.
## Why You Shouldn't Use * For Import
Personally, I would perfer [Mu editor](https://codewith.mu/) for any beginners. It has code check, (limited) auto-complete and can automatically detect/upload code to your micro:bit.
If you have experiences in standard Python or MicroPython with ESP8266/ESP32 (or CircuitPython), you can consider [Thonny](https://thonny.org/) which allows you to access micro:bit's REPL directly without having to switch tabs.
## Why You Shouldn Aviud Import *
The following import statement
@@ -63,9 +69,9 @@ The following import statement
from microbit import *
```
is a bad idea. This imports everything of the microbit module even you don't need many of the features and wastes extra memory.
is a bad idea. This imports everything from the big microbit module even you don't need many of the features and thus waste memory.
Instead, you should only import sub-modules you are going to use:
Instead, you should import the only submodules you are going to use:
```python
from microbit import pin0, display, sleep
@@ -88,13 +94,9 @@ gc.enable() # auto memory recycle
gc.collect() # force memory recycle
```
## Editor of Choice
## Recursion is Not Welcomed
The official [Python online editor](https://python.microbit.org/v/2.0) does not need installation and can be used anywhere with Internet and Chrome web browser. Support Web-USB. It's ok to use, really.
Personally, I would perfer [Mu editor](https://codewith.mu/) for any beginners. It has code check, (limited) auto-complete and can automatically detect/upload code to your micro:bit.
If you have experiences with MicroPython with ESP8266/ESP32 or CircuitPython, you can consider [Thonny](https://thonny.org/) which allows you to access micro:bit's REPL directly without having to upload hex file.
Recursion depth (how many level can a function calls itself) is severely limited because of the memory constraint. Only [8 nested function calls or so](https://mail.python.org/pipermail/microbit/2016-February/000896.html) can be used without triggering RuntimeError. So sadly it's not possible to do some popular algorithms on micro:bit.
## Classic Blinky
@@ -150,7 +152,7 @@ while True:
for _ in range(2):
fillScreen()
sleep(100)
fillScreen(0)
display.clear()
sleep(100)
for i in range(9):
@@ -214,7 +216,7 @@ while True:
since2 = utime.ticks_ms()
```
## A More Convenient Pin Class
## A More Convenient Pin Class?
Make a Pin class to "rename" existing pin methods.
@@ -254,7 +256,7 @@ while True:
sleep(50)
```
## Another Version of Pin Class
## Simpler Alternate Pin Class
Use **namedtuple** as a simple Pin class. Might save more memory than regular class.
@@ -432,6 +434,8 @@ while True:
## Calcualte Fibonacci Sequence
[Fibonacci sequence](https://en.wikipedia.org/wiki/Fibonacci_number)
```python
from microbit import display
@@ -448,7 +452,7 @@ display.scroll(b)
## Calcuate a List of Prime Numbers
Prime numbers (except 2, 3) are either 6n - 1 or 6n + 1.
Prime numbers (except 2, 3) are either 6n - 1 or 6n + 1. So we check if a number of 6n - 1/6n + 1 can be divided with any existing primes in the list. If not, it is a prime number and can be added to the list.
```python
from microbit import display
@@ -473,7 +477,7 @@ for prime in primes:
## Conway's Game of Life on 5x5 LED Display
The code would reset the micro:bit if there's no cell left or the cells are stable.
The code would reset the micro:bit if there's no cell left or the cells are stable. Although sometimes it may be locked into a state with the same alternating cell numbers and need manual reset.
```python
from microbit import display
@@ -548,7 +552,7 @@ while True:
This allows you to enter your message and display it as Morse code on the LED screen. Go to the REPL mode and reset micro:bit to make it work.
If you attach a passive buzzer between pin 0 and ground you can hear it too.
If you attach a passive buzzer between pin 0 and ground you can hear the Morse code too.
```python
from microbit import display, Image, sleep