Simon Says..."turn that ruler into an interactive memorization game with leds and touch pads!"

In this guide you can turn the Adafruit PyRuler into a clone of the classic game known as Simon

Using CircuitPython, and the PyRuler's leds and capacitive touch pads we can make the PyRuler into our own Simon game. We can program the PyRuler to output patterns to the leds to memorize and then read capacitive touch inputs

This guide and code was adapted from Miguel Grinberg's guide: Simon Game Clone with Circuit Playground Express and CircuitPython

Reference guide

This is a great guide to use as a reference for all things PyRuler including pinouts, specs and more.

Parts

The first time you soldered up a surface mount component you may have been surprised "these are really small parts!" and there's a dozen of different names...
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CircuitPython is a derivative of MicroPython designed to simplify experimentation and education on low-cost microcontrollers. It makes it easier than ever to get prototyping by requiring no upfront desktop software downloads. The trinket M0 is the second board that comes pre-loaded with CircuitPython. Simply copy and edit files on the CIRCUITPY drive to iterate.

Your PyRuler already comes with CircuitPython but maybe there's a new version, or you overwrote your Trinket M0 with Arduino code! In that case, see the below for how to reinstall or update CircuitPython. Otherwise you can skip this and go straight to the next page!

If you have already plugged in your board, start by ejecting or "safely remove" the CIRCUITPY drive. This is a good practice to get into. Always eject before unplugging or resetting your board!

Set up CircuitPython Quick Start!

Follow this quick step-by-step for super-fast Python power :)

Click the link above and download the latest UF2 file.

Download and save it to your desktop (or wherever is handy).

Plug your PyRuler into your computer using a known-good USB cable.

A lot of people end up using charge-only USB cables and it is very frustrating! So make sure you have a USB cable you know is good for data sync.

Double-click the small Reset button next to the Trinket M0 name printed on your board, and you will see the Dotstar RGB LED, noted by the green arrow in the image, turn green. If it turns red, check the USB cable, try another USB port, etc. Note: The little LED above the USB connector will be red - this is ok!

If double-clicking doesn't work the first time, try again. Sometimes it can take a few tries to get the rhythm right!

You will see a new disk drive appear called TRINKETBOOT.

 

 

 

Drag the adafruit_circuitpython_etc.uf2 file to TRINKETBOOT

The red LED will flash. Then, the TRINKETBOOT drive will disappear and a new disk drive called CIRCUITPY will appear.

That's it, you're done! :)

Further Information

For more detailed info on installing CircuitPython, check out Installing CircuitPython.

Mu is a simple code editor that works with the Adafruit CircuitPython boards. It's written in Python and works on Windows, MacOS, Linux and Raspberry Pi. The serial console is built right in so you get immediate feedback from your board's serial output!

Mu is our recommended editor - please use it (unless you are an experienced coder with a favorite editor already!).

Download and Install Mu

Download Mu from https://codewith.mu.

Click the Download link for downloads and installation instructions.

Click Start Here to find a wealth of other information, including extensive tutorials and and how-to's.

 

Windows users: due to the nature of MSI installers, please remove old versions of Mu before installing the latest version.

Starting Up Mu

The first time you start Mu, you will be prompted to select your 'mode' - you can always change your mind later. For now please select CircuitPython!

The current mode is displayed in the lower right corner of the window, next to the "gear" icon. If the mode says "Microbit" or something else, click the Mode button in the upper left, and then choose "CircuitPython" in the dialog box that appears.

Mu attempts to auto-detect your board on startup, so if you do not have a CircuitPython board plugged in with a CIRCUITPY drive available, Mu will inform you where it will store any code you save until you plug in a board.

To avoid this warning, plug in a board and ensure that the CIRCUITPY drive is mounted before starting Mu.

Using Mu

You can now explore Mu! The three main sections of the window are labeled below; the button bar, the text editor, and the serial console / REPL.

Now you're ready to code! Let's keep going...

One of the best things about CircuitPython is how simple it is to get code up and running. This section covers how to create and edit your first CircuitPython program.

To create and edit code, all you'll need is an editor. There are many options. Adafruit strongly recommends using Mu! It's designed for CircuitPython, and it's really simple and easy to use, with a built in serial console!

If you don't or can't use Mu, there are a number of other editors that work quite well. The Recommended Editors page has more details. Otherwise, make sure you do "Eject" or "Safe Remove" on Windows or "sync" on Linux after writing a file if you aren't using Mu. (This is not a problem on MacOS.)

Creating Code

Installing CircuitPython generates a code.py file on your CIRCUITPY drive. To begin your own program, open your editor, and load the code.py file from the CIRCUITPY drive.

If you are using Mu, click the Load button in the button bar, navigate to the CIRCUITPY drive, and choose code.py.

Copy and paste the following code into your editor:

import board
import digitalio
import time

led = digitalio.DigitalInOut(board.LED)
led.direction = digitalio.Direction.OUTPUT

while True:
    led.value = True
    time.sleep(0.5)
    led.value = False
    time.sleep(0.5)
The QT Py and the Trinkeys do not have a built-in little red LED! There is an addressable RGB NeoPixel LED. The above example will NOT work on the QT Py or the Trinkeys!

If you're using QT Py or a Trinkey, please download the NeoPixel blink example.

The NeoPixel blink example uses the onboard NeoPixel, but the time code is the same. You can use the linked NeoPixel Blink example to follow along with this guide page.

It will look like this. Note that under the while True: line, the next four lines begin with four spaces to indent them, and they're indented exactly the same amount. All the lines before that have no spaces before the text.

Save the code.py file on your CIRCUITPY drive.

The little LED should now be blinking. Once per half-second.

Congratulations, you've just run your first CircuitPython program!

On most boards you'll find a tiny red LED. On the ItsyBitsy nRF52840, you'll find a tiny blue LED. On QT Py M0, QT Py RP2040, and the Trinkey series, you will find only an RGB NeoPixel LED.

Editing Code

To edit code, open the code.py file on your CIRCUITPY drive into your editor.

 

Make the desired changes to your code. Save the file. That's it!

Your code changes are run as soon as the file is done saving.

There's one warning before you continue...

Don't click reset or unplug your board!

The CircuitPython code on your board detects when the files are changed or written and will automatically re-start your code. This makes coding very fast because you save, and it re-runs. If you unplug or reset the board before your computer finishes writing the file to your board, you can corrupt the drive. If this happens, you may lose the code you've written, so it's important to backup your code to your computer regularly.

There are a couple of ways to avoid filesystem corruption.

1. Use an editor that writes out the file completely when you save it.

Check out the Recommended Editors page for details on different editing options.

If you are dragging a file from your host computer onto the CIRCUITPY drive, you still need to do step 2. Eject or Sync (below) to make sure the file is completely written.

2. Eject or Sync the Drive After Writing

If you are using one of our not-recommended-editors, not all is lost! You can still make it work.

On Windows, you can Eject or Safe Remove the CIRCUITPY drive. It won't actually eject, but it will force the operating system to save your file to disk. On Linux, use the sync command in a terminal to force the write to disk.

You also need to do this if you use Windows Explorer or a Linux graphical file manager to drag a file onto CIRCUITPY.

Oh No I Did Something Wrong and Now The CIRCUITPY Drive Doesn't Show Up!!!

Don't worry! Corrupting the drive isn't the end of the world (or your board!). If this happens, follow the steps found on the Troubleshooting page of every board guide to get your board up and running again.

Back to Editing Code...

Now! Let's try editing the program you added to your board. Open your code.py file into your editor. You'll make a simple change. Change the first 0.5 to 0.1. The code should look like this:

import board
import digitalio
import time

led = digitalio.DigitalInOut(board.LED)
led.direction = digitalio.Direction.OUTPUT

while True:
    led.value = True
    time.sleep(0.1)
    led.value = False
    time.sleep(0.5)

Leave the rest of the code as-is. Save your file. See what happens to the LED on your board? Something changed! Do you know why?

You don't have to stop there! Let's keep going. Change the second 0.5 to 0.1 so it looks like this:

while True:
    led.value = True
    time.sleep(0.1)
    led.value = False
    time.sleep(0.1)

Now it blinks really fast! You decreased the both time that the code leaves the LED on and off!

Now try increasing both of the 0.1 to 1. Your LED will blink much more slowly because you've increased the amount of time that the LED is turned on and off.

Well done! You're doing great! You're ready to start into new examples and edit them to see what happens! These were simple changes, but major changes are done using the same process. Make your desired change, save it, and get the results. That's really all there is to it!

Naming Your Program File

CircuitPython looks for a code file on the board to run. There are four options: code.txt, code.py, main.txt and main.py. CircuitPython looks for those files, in that order, and then runs the first one it finds. While code.py is the recommended name for your code file, it is important to know that the other options exist. If your program doesn't seem to be updating as you work, make sure you haven't created another code file that's being read instead of the one you're working on.

As CircuitPython development continues and there are new releases, Adafruit will stop supporting older releases. Visit https://circuitpython.org/downloads to download the latest version of CircuitPython for your board. You must download the CircuitPython Library Bundle that matches your version of CircuitPython. Please update CircuitPython and then visit https://circuitpython.org/libraries to download the latest Library Bundle.

Each CircuitPython program you run needs to have a lot of information to work. The reason CircuitPython is so simple to use is that most of that information is stored in other files and works in the background. These files are called libraries. Some of them are built into CircuitPython. Others are stored on your CIRCUITPY drive in a folder called lib. Part of what makes CircuitPython so great is its ability to store code separately from the firmware itself. Storing code separately from the firmware makes it easier to update both the code you write and the libraries you depend.

Your board may ship with a lib folder already, it's in the base directory of the drive. If not, simply create the folder yourself. When you first install CircuitPython, an empty lib directory will be created for you.

CircuitPython libraries work in the same way as regular Python modules so the Python docs are an excellent reference for how it all should work. In Python terms, you can place our library files in the lib directory because it's part of the Python path by default.

One downside of this approach of separate libraries is that they are not built in. To use them, one needs to copy them to the CIRCUITPY drive before they can be used. Fortunately, there is a library bundle.

The bundle and the library releases on GitHub also feature optimized versions of the libraries with the .mpy file extension. These files take less space on the drive and have a smaller memory footprint as they are loaded.

Due to the regular updates and space constraints, Adafruit does not ship boards with the entire bundle. Therefore, you will need to load the libraries you need when you begin working with your board. You can find example code in the guides for your board that depends on external libraries.

Either way, as you start to explore CircuitPython, you'll want to know how to get libraries on board.

The Adafruit CircuitPython Library Bundle

Adafruit provides CircuitPython libraries for much of the hardware they provide, including sensors, breakouts and more. To eliminate the need for searching for each library individually, the libraries are available together in the Adafruit CircuitPython Library Bundle. The bundle contains all the files needed to use each library.

Downloading the Adafruit CircuitPython Library Bundle

You can download the latest Adafruit CircuitPython Library Bundle release by clicking the button below. The libraries are being constantly updated and improved, so you'll always want to download the latest bundle. 

Match up the bundle version with the version of CircuitPython you are running. For example, you would download the 6.x library bundle if you're running any version of CircuitPython 6, or the 7.x library bundle if you're running any version of CircuitPython 7, etc. If you mix libraries with major CircuitPython versions, you will get incompatible mpy errors due to changes in library interfaces possible during major version changes.

Download the bundle version that matches your CircuitPython firmware version. If you don't know the version, check the version info in boot_out.txt file on the CIRCUITPY drive, or the initial prompt in the CircuitPython REPL. For example, if you're running v7.0.0, download the 7.x library bundle.

There's also a py bundle which contains the uncompressed python files, you probably don't want that unless you are doing advanced work on libraries.

The CircuitPython Community Library Bundle

The CircuitPython Community Library Bundle is made up of libraries written and provided by members of the CircuitPython community. These libraries are often written when community members encountered hardware not supported in the Adafruit Bundle, or to support a personal project. The authors all chose to submit these libraries to the Community Bundle make them available to the community.

These libraries are maintained by their authors and are not supported by Adafruit. As you would with any library, if you run into problems, feel free to file an issue on the GitHub repo for the library. Bear in mind, though, that most of these libraries are supported by a single person and you should be patient about receiving a response. Remember, these folks are not paid by Adafruit, and are volunteering their personal time when possible to provide support.

Downloading the CircuitPython Community Library Bundle

You can download the latest CircuitPython Community Library Bundle release by clicking the button below. The libraries are being constantly updated and improved, so you'll always want to download the latest bundle.

The link takes you to the latest release of the CircuitPython Community Library Bundle on GitHub. There are multiple versions of the bundle available. Download the bundle version that matches your CircuitPython firmware version. If you don't know the version, check the version info in boot_out.txt file on the CIRCUITPY drive, or the initial prompt in the CircuitPython REPL. For example, if you're running v7.0.0, download the 7.x library bundle.

Understanding the Bundle

After downloading the zip, extract its contents. This is usually done by double clicking on the zip. On Mac OSX, it places the file in the same directory as the zip.

Open the bundle folder. Inside you'll find two information files, and two folders. One folder is the lib bundle, and the other folder is the examples bundle.

Now open the lib folder. When you open the folder, you'll see a large number of .mpy files, and folders.

Example Files

All example files from each library are now included in the bundles in an examples directory (as seen above), as well as an examples-only bundle. These are included for two main reasons:

  • Allow for quick testing of devices.
  • Provide an example base of code, that is easily built upon for individualized purposes.

Copying Libraries to Your Board

First open the lib folder on your CIRCUITPY drive. Then, open the lib folder you extracted from the downloaded zip. Inside you'll find a number of folders and .mpy files. Find the library you'd like to use, and copy it to the lib folder on CIRCUITPY.

If the library is a directory with multiple .mpy files in it, be sure to copy the entire folder to CIRCUITPY/lib.

This also applies to example files. Open the examples folder you extracted from the downloaded zip, and copy the applicable file to your CIRCUITPY drive. Then, rename it to code.py to run it.

If a library has multiple .mpy files contained in a folder, be sure to copy the entire folder to CIRCUITPY/lib.

Understanding Which Libraries to Install

You now know how to load libraries on to your CircuitPython-compatible microcontroller board. You may now be wondering, how do you know which libraries you need to install? Unfortunately, it's not always straightforward. Fortunately, there is an obvious place to start, and a relatively simple way to figure out the rest. First up: the best place to start.

When you look at most CircuitPython examples, you'll see they begin with one or more import statements. These typically look like the following:

  • import library_or_module

However, import statements can also sometimes look like the following:

  • from library_or_module import name
  • from library_or_module.subpackage import name
  • from library_or_module import name as local_name

They can also have more complicated formats, such as including a try / except block, etc.

The important thing to know is that an import statement will always include the name of the module or library that you're importing.

Therefore, the best place to start is by reading through the import statements.

Here is an example import list for you to work with in this section. There is no setup or other code shown here, as the purpose of this section involves only the import list.

import time
import board
import neopixel
import adafruit_lis3dh
import usb_hid
from adafruit_hid.consumer_control import ConsumerControl
from adafruit_hid.consumer_control_code import ConsumerControlCode

Keep in mind, not all imported items are libraries. Some of them are almost always built-in CircuitPython modules. How do you know the difference? Time to visit the REPL.

In the Interacting with the REPL section on The REPL page in this guide, the help("modules") command is discussed. This command provides a list of all of the built-in modules available in CircuitPython for your board. So, if you connect to the serial console on your board, and enter the REPL, you can run help("modules") to see what modules are available for your board. Then, as you read through the import statements, you can, for the purposes of figuring out which libraries to load, ignore the statement that import modules.

The following is the list of modules built into CircuitPython for the Feather RP2040. Your list may look similar or be anything down to a significant subset of this list for smaller boards.

Now that you know what you're looking for, it's time to read through the import statements. The first two, time and board, are on the modules list above, so they're built-in.

The next one, neopixel, is not on the module list. That means it's your first library! So, you would head over to the bundle zip you downloaded, and search for neopixel. There is a neopixel.mpy file in the bundle zip. Copy it over to the lib folder on your CIRCUITPY drive. The following one, adafruit_lis3dh, is also not on the module list. Follow the same process for adafruit_lis3dh, where you'll find adafruit_lis3dh.mpy, and copy that over.

The fifth one is usb_hid, and it is in the modules list, so it is built in. Often all of the built-in modules come first in the import list, but sometimes they don't! Don't assume that everything after the first library is also a library, and verify each import with the modules list to be sure. Otherwise, you'll search the bundle and come up empty!

The final two imports are not as clear. Remember, when import statements are formatted like this, the first thing after the from is the library name. In this case, the library name is adafruit_hid. A search of the bundle will find an adafruit_hid folder. When a library is a folder, you must copy the entire folder and its contents as it is in the bundle to the lib folder on your CIRCUITPY drive. In this case, you would copy the entire adafruit_hid folder to your CIRCUITPY/lib folder.

Notice that there are two imports that begin with adafruit_hid. Sometimes you will need to import more than one thing from the same library. Regardless of how many times you import the same library, you only need to load the library by copying over the adafruit_hid folder once.

That is how you can use your example code to figure out what libraries to load on your CircuitPython-compatible board!

There are cases, however, where libraries require other libraries internally. The internally required library is called a dependency. In the event of library dependencies, the easiest way to figure out what other libraries are required is to connect to the serial console and follow along with the ImportError printed there. The following is a very simple example of an ImportError, but the concept is the same for any missing library.

Example: ImportError Due to Missing Library

If you choose to load libraries as you need them, or you're starting fresh with an existing example, you may end up with code that tries to use a library you haven't yet loaded.  This section will demonstrate what happens when you try to utilise a library that you don't have loaded on your board, and cover the steps required to resolve the issue.

This demonstration will only return an error if you do not have the required library loaded into the lib folder on your CIRCUITPY drive.

Let's use a modified version of the Blink example.

import board
import time
import simpleio

led = simpleio.DigitalOut(board.LED)

while True:
    led.value = True
    time.sleep(0.5)
    led.value = False
    time.sleep(0.5)

Save this file. Nothing happens to your board. Let's check the serial console to see what's going on.

You have an ImportError. It says there is no module named 'simpleio'. That's the one you just included in your code!

Click the link above to download the correct bundle. Extract the lib folder from the downloaded bundle file. Scroll down to find simpleio.mpy. This is the library file you're looking for! Follow the steps above to load an individual library file.

The LED starts blinking again! Let's check the serial console.

No errors! Excellent. You've successfully resolved an ImportError!

If you run into this error in the future, follow along with the steps above and choose the library that matches the one you're missing.

Library Install on Non-Express Boards

If you have an M0 non-Express board such as Trinket M0, Gemma M0, QT Py M0, or one of the M0 Trinkeys, you'll want to follow the same steps in the example above to install libraries as you need them. Remember, you don't need to wait for an ImportError if you know what library you added to your code. Open the library bundle you downloaded, find the library you need, and drag it to the lib folder on your CIRCUITPY drive.

You can still end up running out of space on your M0 non-Express board even if you only load libraries as you need them. There are a number of steps you can use to try to resolve this issue. You'll find suggestions on the Troubleshooting page.

Updating CircuitPython Libraries and Examples

Libraries and examples are updated from time to time, and it's important to update the files you have on your CIRCUITPY drive.

To update a single library or example, follow the same steps above. When you drag the library file to your lib folder, it will ask if you want to replace it. Say yes. That's it!

A new library bundle is released every time there's an update to a library. Updates include things like bug fixes and new features. It's important to check in every so often to see if the libraries you're using have been updated.

CircuitPython Code

In the embedded code element below, click on the Download: Project Zip link, and save the .zip archive file to your computer.

Then, uncompress the .zip file, it will unpack to a folder named PyRuler_Simon_Game.

Copy the contents of the PyRuler_Simon_Game directory to your PyRuler's CIRCUITPY drive which will show up in your operating systems file explorer/finder when the board is plugged in via a known good USB cable. Ensure your Python code is named code.py.

"""
This example runs the 'Simon' game on the PyRuler.
Memorize each led sequence and tap the corresponding
touch pads on the pyruler to advance to each new sequence.
Code adapted from Miguel Grinberg's Simon game for Circuit Playground Express

"""

import time
import random
import board
from rainbowio import colorwheel
from digitalio import DigitalInOut, Direction
import touchio
import adafruit_dotstar

# Initialize dot star led
pixels = adafruit_dotstar.DotStar(board.APA102_SCK, board.APA102_MOSI,
                                  1, brightness=0.1)
red = (255,0,0)
green = (0,255,0)
blue = (0,0,255)

led = DigitalInOut(board.D13)
led.direction = Direction.OUTPUT

touches = [DigitalInOut(board.CAP0)]
for p in (board.CAP1, board.CAP2, board.CAP3):
    touches.append(touchio.TouchIn(p))

leds = []
for p in (board.LED4, board.LED5, board.LED6, board.LED7):
    led = DigitalInOut(p)
    led.direction = Direction.OUTPUT
    leds.append(led)

cap_touches = [False, False, False, False]


def rainbow_cycle(wait):
    for j in range(255):
        for i in range(len(pixels)):
            rc_index = (i * 256 // len(pixels)) + j
            pixels[i] = colorwheel(rc_index & 255)
        time.sleep(wait)

def read_caps():
    t0_count = 0
    t0 = touches[0]
    t0.direction = Direction.OUTPUT
    t0.value = True
    t0.direction = Direction.INPUT
    # funky idea but we can 'diy' the one non-hardware captouch device by hand
    # by reading the drooping voltage on a tri-state pin.
    t0_count = t0.value + t0.value + t0.value + t0.value + t0.value + \
               t0.value + t0.value + t0.value + t0.value + t0.value + \
               t0.value + t0.value + t0.value + t0.value + t0.value
    cap_touches[0] = t0_count > 2
    cap_touches[1] = touches[1].raw_value > 3000
    cap_touches[2] = touches[2].raw_value > 3000
    cap_touches[3] = touches[3].raw_value > 3000
    return cap_touches

def timeout_touch(timeout=3):
    start_time = time.monotonic() # start 3 second timer waiting for user input
    while time.monotonic() - start_time < timeout:
        caps = read_caps()
        for i,c in enumerate(caps):
            if c:
                return i

def light_cap(cap, duration=0.5):
    # turn the LED for the selected cap on
    leds[cap].value = True
    time.sleep(duration)
    leds[cap].value = False
    time.sleep(duration)

def play_sequence(seq):
    duration = max(0.1, 1 - len(sequence) * 0.05)
    for cap in seq:
        light_cap(cap, duration)

def read_sequence(seq):
    pixels.fill(green)
    for cap in seq:
        if timeout_touch() != cap:
            # the player made a mistake!
            return False
        light_cap(cap, 0.5)
    return True

while True:
    # led light sequence at beginning of each game
    pixels.fill(blue)
    time.sleep(1)
    for led in leds:
        led.value = True
        time.sleep(0.25)
    for led in leds:
        led.value = False
    sequence = []
    while True:
        pixels.fill(blue) # blue for showing user sequence
        time.sleep(1)
        sequence.append(random.randint(0, 3)) # add new light to sequence each time
        play_sequence(sequence) # show the sequence
        if not read_sequence(sequence): # if user inputs wrong sequence, gameover
            # game over, make dot star red
            pixels.fill(red)
            time.sleep(3)
            print("gameover")
            break
        else:
            print("Next sequence unlocked!")
            rainbow_cycle(0) # Dot star animation after each correct sequence
        pixels.fill(0)
        time.sleep(1)

Downloading the libraries

Make sure to add the necessary libraries to the lib folder, info on how to do this can be found in the "CircuitPython Libraries" section

This project uses the following CircuitPython libraries:

  • adafruit_dotstar (file)
  • adafruit_hid (directory)

This is what the final contents of the CIRCUITPY drive will look like:

Game play

To play the Simon game, power up the PyRuler by plugging in a USB cable connected to a computer or a USB cell phone battery.

You will see the 4 leds above each touch pad light up in sequence then turn off.

Next, you will see one of the 4 leds turn on and off.

Then the DotStar RGB LED on the Trinket-sized circuit board will turn green prompting you to touch the pad corresponding to the led that was just on.

If you correctly input the given pattern, the DotStar led will cycle through a random pattern and the next pattern will be shown.

Each future pattern has the same initial sequence from before with one more added to the sequence each time.

When the DotStar is blue, the program is showing you the sequence.

If you get a sequence wrong, the DotStar will turn red then the game will start over with the leds cycling through the intro pattern.

How the code works

Here's what's going on behind the scenes to deliver you the Simon game you know and love.

Initialization

This segment towards the beginning of the program initializes the 4 touch pads on the PyRuler as well as the corresponding 4 leds.

touches = [DigitalInOut(board.CAP0)]
for p in (board.CAP1, board.CAP2, board.CAP3):
    touches.append(touchio.TouchIn(p))

leds = []
for p in (board.LED4, board.LED5, board.LED6, board.LED7):
    led = DigitalInOut(p)
    led.direction = Direction.OUTPUT
    leds.append(led)

cap_touches = [False, False, False, False]

Functions

These functions simplify and optimize how the program runs.

DotStar code

This part shows how the rainbow pattern for the dot star works.

def wheel(pos):
    # Input a value 0 to 255 to get a color value.
    # The colours are a transition r - g - b - back to r.
    if pos < 0 or pos > 255:
        return (0, 0, 0)
    if pos < 85:
        return (255 - pos * 3, pos * 3, 0)
    if pos < 170:
        pos -= 85
        return (0, 255 - pos * 3, pos * 3)
    pos -= 170
    return (pos * 3, 0, 255 - pos * 3)

def rainbow_cycle(wait):
    for j in range(255):
        for i in range(len(pixels)):
            rc_index = (i * 256 // len(pixels)) + j
            pixels[i] = wheel(rc_index & 255)
        time.sleep(wait)

Detecting capacitive touch and setting a timer

Up next we read input from the PyRuler capacitive touch pads with the read_caps() function. Then with the timeout_touch() function we set a 3 second timer after each pattern is displayed as well as in-between each touch.

def read_caps():
    t0_count = 0
    t0 = touches[0]
    t0.direction = Direction.OUTPUT
    t0.value = True
    t0.direction = Direction.INPUT
    # funky idea but we can 'diy' the one non-hardware captouch device by hand
    # by reading the drooping voltage on a tri-state pin.
    t0_count = t0.value + t0.value + t0.value + t0.value + t0.value + \
               t0.value + t0.value + t0.value + t0.value + t0.value + \
               t0.value + t0.value + t0.value + t0.value + t0.value
    cap_touches[0] = t0_count > 2
    cap_touches[1] = touches[1].raw_value > 3000
    cap_touches[2] = touches[2].raw_value > 3000
    cap_touches[3] = touches[3].raw_value > 3000
    return cap_touches

def timeout_touch(timeout=3):
    start_time = time.monotonic() # start 3 second timer waiting for user input
    while time.monotonic() - start_time < timeout:
        caps = read_caps()
        for i,c in enumerate(caps):
            if c:
                return i

Playing and reading each sequence with leds

  • light_cap() turns on the led associated with each touch pad if the pad was touched.
  • play_sequence() plays each led for the given sequence and slowly speeds up the playback of each sequence as they get longer.
  • read_sequence() First turns the DotStar green (indicating to user to enter the sequence) then reads the touch pads and determines if they are the right sequence. If the wrong pad was touched, the function returns False which will cause a game over (more on this later).
def light_cap(cap, duration=0.5):
    # turn the LED for the selected cap on
    leds[cap].value = True
    time.sleep(duration)
    leds[cap].value = False
    time.sleep(duration)

def play_sequence(seq):
    duration = max(0.1, 1 - len(sequence) * 0.05)
    for cap in seq:
        light_cap(cap, duration)

def read_sequence(seq):
    pixels.fill(green)
    for cap in seq:
        if timeout_touch() != cap:
            # the player made a mistake!
            return False
        light_cap(cap, 0.5)
    return True

The main loop

  • First trigger the starting sequence of leds demonstrating the game is beginning.
  • Next in a nested loop, turn the DotStar blue demonstrating the sequence is being shown.
  • Then add a random number between 0 and 3 to the sequence and play the sequence. 
    • If the user enters the wrong sequence or the time runs out, turn the DotStar red indicating game over, and exit the loop starting the game over at the top of the main loop.
    • Otherwise, trigger the rainbow animation on the DotStar (indicating a correct sequence) and move to next sequence.
while True:
    # led light sequence at beginning of each game
    pixels.fill(blue)
    time.sleep(1)
    for led in leds:
        led.value = True
        time.sleep(0.25)
    for led in leds:
        led.value = False
    sequence = []
    while True:
        pixels.fill(blue) # blue for showing user sequence
        time.sleep(1)
        sequence.append(random.randint(0, 3)) # add new light to sequence each time
        play_sequence(sequence) # show the sequence
        if not read_sequence(sequence): # if user inputs wrong sequence, gameover
            # game over, make dot star red
            pixels.fill(red)
            time.sleep(3)
            print("gameover")
            break
        else:
            print("Next sequence unlocked!")
            rainbow_cycle(0) # Dot star animation after each correct sequence
        pixels.fill(0)
        time.sleep(1)

That's it, now you're a CircuitPython wiz!

Simon Says time to make your own game with the PyRuler!

This guide was first published on Aug 15, 2019. It was last updated on Aug 15, 2019.