Tinkering workshop

Introduction on Adafruit Circuit Playground Express

Install mu editor

Python is the fastest-growing programming language. And CircuitPython is based on Python language but designed to run on microcontroller boards.

CircuitPython is designed with education in mind.

It's easy to start learning how to program and you get immediate feedback from the board.

Before we start we all have to do this to set up:

1. Install or update CircuitPython!

https://learn.adafruit.com/adafruit-circuit-playground-express/circuitpython-quickstart

*1. Click the link below and download the latest UF2 file:
https://circuitpython.org/board/circuitplayground_express/

*2. Plug your Circuit Playground Express into your computer via a (data)USB cable.

*3. Double-click the small Reset button in the middle of the CPX(short for circuit playground express).
 you will see all of the LEDs turn green. If they turn all red, check the USB cable, try another USB port, etc.
 (If double-clicking doesn't do it, try a single-click!)

*4. You will see a new disk drive appear called CPLAYBOOT
  Drag the adafruit-circuitpython-etc...uf2 file onto it.

*5. The CPLAYBOOT drive will disappear and a new disk drive will appear called CIRCUITPY

That's it! You're done :)

2. Installing Mu Editor

Download Mu from(if you are using computers from school, the Mu Editor is already installed)

https://codewith.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!

Mu attempts to auto-detect your board, so please plug in your CircuitPython device and make sure it shows up as a CIRCUITPY drive before starting Mu

SAVE AS:

if you want to save the code.py file in different names as well as in different locations:

double click on the file name in Mu editor.

Indentation and commenting options

Python programs are Space holder Character Sensitive.

To indent the three lines, I selected them all and then pressed the Tab key.

To unindent, select some lines and press Shift-Tab. For commenting: select lines and press command(control)-k

3. Hello World (Blink in Circuitpython)

 1    import board
 2    import digitalio
 3    import time
 4     
 5    led = digitalio.DigitalInOut(board.D13)
 6    led.direction = digitalio.Direction.OUTPUT
 7     
 8    while True:
 9        led.value = True
10        time.sleep(0.5)
11        led.value = False
12        time.sleep(0.5)

4. Interacting to the Serial Console

The REPL

The other feature of the serial connection is the Read-Evaluate-Print-Loop, or REPL.

The REPL allows you to enter individual lines of code and have them run immediately.

It's really handy if you're running into trouble with a particular program and can't figure out why.

It's interactive so it's great for testing new ideas.

To use the REPL, you first need to be connected to the serial console.

Once that connection has been established, you'll want to press Ctrl + C.

If there is code running, it will stop and you'll see Press any key to enter the REPL. Use CTRL-D to reload.

Follow those instructions, and press any key on your keyboard.

https://learn.adafruit.com/adafruit-circuit-playground-express/the-repl

CircuitPython Made Easy

Libraries:

Libraries are codes other people have written for you. The libraries we will be using are included as part of the CircuitPython code, but you still must import them into your program. Other libraries, for many uses, must be downloaded and placed in a folder named lib on the CIRCUITPY drive.

CircuitPython Libraries already included in CPX, But if you are using CPB, (CPX = Circuit Playground Express, CPB = Circuit Playground Bluefruit)

you need to install CircuitPython Libraries by download the file and put them in the folder named lib on the CIRCUITPY drive.

we will useCircuitPython Made Easy libraries, a simple way to include the Circuit Playground functionality in our code.

more reference and examples:

https://learn.adafruit.com/circuitpython-made-easy-on-circuit-playground-express

code examples

During this workshop, we will learn how to design and create an interactive game that enhances communication,

expression, and collaboration in the current 1.5 social distance reality.

we will focus on sending “touch signal” to each other without physical contact,

but in the forms of lights, color and sound.

1.Neopixel smiley face

A Smiley Face😊

 1from adafruit_circuitplayground import cp
 2
 3# The NeoPixels are super-bright. Change the global brightness.
 4cp.pixels.brightness = 0.3
 5
 6while True:
 7    # The smiley's eyes
 8    cp.pixels[1] = (255, 0, 0)
 9    cp.pixels[3] = (255, 0, 0)
10
11    # The smiley's mouth
12    cp.pixels[5] = (255, 0, 255)
13    cp.pixels[6] = (255, 0, 255)
14    cp.pixels[7] = (255, 0, 255)
15    cp.pixels[8] = (255, 0, 255)
16    cp.pixels[9] = (255, 0, 255)

Let's blink a smiley face by using time.sleep

 1from adafruit_circuitplayground import cp
 2 
 3# The NeoPixels are super-bright. Change the global brightness.
 4cp.pixels.brightness = 0.3
 5
 6import time  
 7
 8while True:
 9    time.sleep(1)
10    # The smiley's eyes
11    cp.pixels[1] = (255, 0, 0)
12    cp.pixels[3] = (255, 0, 0)
13 
14    # The smiley's mouth
15    cp.pixels[5] = (255, 0, 255)
16    cp.pixels[6] = (255, 0, 255)
17    cp.pixels[7] = (255, 0, 255)
18    cp.pixels[8] = (255, 0, 255)
19    cp.pixels[9] = (255, 0, 255)
20    time.sleep(1)
21
22    # The smiley's eyes
23    cp.pixels[1] = (0, 0, 0)
24    cp.pixels[3] = (0, 0, 0)
25 
26    # The smiley's mouth
27    cp.pixels[5] = (0, 0, 0)
28    cp.pixels[6] = (0, 0, 0)
29    cp.pixels[7] = (0, 0, 0)
30    cp.pixels[8] = (0, 0, 0)
31    cp.pixels[9] = (0, 0, 0)

hmm... now the code seems to be too long

let's Shorten the code by implementing variables, "for" loops

 1import time
 2from adafruit_circuitplayground import cp
 3#neoPixel pins for the smiley face
 4pixels_pin=[1,  3,  5, 6, 7, 8, 9,10]
 5# The NeoPixels are super-bright. Change the global brightness.
 6cp.pixels.brightness = 0.1
 7light_colour=(105,0,105)
 8OFF=(0,0,0)
 9
10while True:
11    for i in range (7):
12        cp.pixels[pixels_pin[i]]=light_colour       
13    time.sleep(1)
14    for i in range (7):
15        cp.pixels[pixels_pin[i]]=OFF     
16    time.sleep(1)

much better!!! now if you add a time.sleep(0.5) in the for loop you will see a fading animation of the smiley face.

Touch sense as trigger

there are in total 7 touch pins on CPX. let's try to use the touch sensor to trigger the smiley face.

if we touch pin A4, The smiley face will appear if not the smiley face will disappear.

 1import time
 2from adafruit_circuitplayground import cp
 3#neoPixel pins for the smiley face
 4pixels_pin=[1,  3,  5, 6, 7, 8, 9,10]
 5# The NeoPixels are super-bright. Change the global brightness.
 6cp.pixels.brightness = 0.1
 7light_colour=(105,0,105)
 8OFF=(0,0,0)
 9
10while True:
11    if cp.touch_A4:
12        for i in range (7):
13            cp.pixels[pixels_pin[i]]=light_colour   
14            time.sleep(.1)
15            print("A4-touched!")
16    else:
17        for i in range (7):
18            cp.pixels[pixels_pin[i]]=OFF     
19            time.sleep(.1)

Touch piano keyboard

 1import time
 2from adafruit_circuitplayground import cp
 3#neoPixel pins for the smiley face
 4pixels_pin=[1,  3,  5, 6, 7, 8, 9,10]
 5 
 6playtime=0.2
 7# NOTE C4-B4
 8c4=262 
 9d4=294
10e4=330
11f4=349
12g4=392
13a4=440
14b4=494
15
16while True:
17    if cp.touch_A1:
18        cp.play_tone(c4, playtime) 
19        print("A1-touched!")
20    if cp.touch_A2:
21        cp.play_tone(d4, playtime)
22        print("A2-touched!")
23    if cp.touch_A3:
24        cp.play_tone(e4, playtime)
25        print("A3-touched!")
26    if cp.touch_A4:
27        cp.play_tone(f4, playtime)
28        print("A4-touched!")
29    if cp.touch_A5:
30        cp.play_tone(g4, playtime)
31        print("A5-touched!")
32    if cp.touch_A6:
33        cp.play_tone(a4, playtime)
34        print("A6-touched!")
35    if cp.touch_A7:
36        cp.play_tone(b4, playtime)
37        print("A7-touched!")

play audio file

here some audio files you can download and copy to the circuit playground express.

[Dip.wav] [Rise.wav][Explosion.wav] [Kiss.wav] [Happy-ringtone.wav] [Wrong-buzzer.wav] [Yelling-yeah.wav] [Jazz-piano.wav]

 1import time
 2from adafruit_circuitplayground import cp
 3#neoPixel pins for the smiley face
 4pixels_pin=[1,  3,  5, 6, 7, 8, 9,10]
 5
 6# The NeoPixels are super-bright. Change the global brightness.
 7cp.pixels.brightness = 0.1
 8colour01=(105,0,105)
 9colour02=(0,100,105)
10OFF=(0,0,0)
11
12while True:
13    if cp.touch_A4:
14        for i in range (7):
15            cp.pixels[pixels_pin[i]]=colour01   
16            time.sleep(0.03)
17            print("A4-touched!")
18        cp.play_file("yelling-yeah.wav")
19    else:
20        for i in range (7):
21            cp.pixels[pixels_pin[i]]=OFF     
22            time.sleep(0.03)
23    if cp.touch_A3:
24        for i in range (7):
25            cp.pixels[pixels_pin[i]]=colour02   
26            time.sleep(0.03)
27            print("A3-touched!")
28 
29        cp.play_file("jazz-piano.wav")
30    else:
31        for i in range (7):
32            cp.pixels[pixels_pin[i]]=OFF
33            time.sleep(0.03)

Drum Machine

https://learn.adafruit.com/adafruit-circuit-playground-express/playground-drum-machine

copy the drum samples there:

[samples]

 1# Circuit Playground 808 Drum machine
 2import time
 3import board
 4import touchio
 5import digitalio
 6 
 7try:
 8    from audiocore import WaveFile
 9except ImportError:
10    from audioio import WaveFile
11 
12try:
13    from audioio import AudioOut
14except ImportError:
15    try:
16        from audiopwmio import PWMAudioOut as AudioOut
17    except ImportError:
18        pass  # not always supported by every board!
19 
20bpm = 120  # Beats per minute, change this to suit your tempo
21 
22# Enable the speaker
23speaker_enable = digitalio.DigitalInOut(board.SPEAKER_ENABLE)
24speaker_enable.direction = digitalio.Direction.OUTPUT
25speaker_enable.value = True
26 
27# Make the input capacitive touchpads
28capPins = (board.A1, board.A2, board.A3, board.A4, board.A5,
29           board.A6, board.TX)
30 
31touchPad = []
32for i in range(7):
33    touchPad.append(touchio.TouchIn(capPins[i]))
34 
35# The seven files assigned to the touchpads
36audiofiles = ["bd_tek.wav", "elec_hi_snare.wav", "elec_cymbal.wav",
37              "elec_blip2.wav", "bd_zome.wav", "bass_hit_c.wav",
38              "drum_cowbell.wav"]
39 
40audio = AudioOut(board.SPEAKER)
41 
42 
43def play_file(filename):
44    print("playing file " + filename)
45    file = open(filename, "rb")
46    wave = WaveFile(file)
47    audio.play(wave)
48    time.sleep(bpm / 960)  # Sixteenth note delay
49 
50 
51while True:
52    for i in range(7):
53        if touchPad[i].value:
54            play_file(audiofiles[i])

connect to a proper speaker:

we can use A0 and GND as audio output and connect it to a proper speaker.

you can use M3 bolts and nuts to fix the electrical wire on the circuit playground express.

infrared tagging game:

  1import board
  2from adafruit_circuitplayground import cp
  3import time
  4import pulseio
  5import array
  6import sys
  7
  8# change into your own color by changing the rgb value
  9myID_color = (0, 55, 50)
 10OFF = (0, 0, 0)
 11color_got_hit = (255, 0, 0)
 12color_got_saved = (100, 0, 100)
 13Neo_smiley_face = [4,  5,  1, 0, 8, 9]
 14full_led = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
 15counter = 0
 16lifes = 10-counter
 17
 18# Initializes NeoPixel ring
 19cp.pixels.brightness = 0.2
 20# my id color
 21cp.pixels.fill(myID_color)
 22
 23
 24# Create IR input, maximum of 59 bits.
 25pulseIn = pulseio.PulseIn(board.IR_RX, maxlen=59, idle_state=True)
 26# Clears any artifacts
 27pulseIn.clear()
 28pulseIn.resume()
 29
 30# Creates IR output pulse
 31pwm = pulseio.PWMOut(board.IR_TX, frequency=38000, duty_cycle=2 ** 15)
 32pulse = pulseio.PulseOut(pwm)
 33
 34# Array for button A pulse, this is the pulse output when the button is pressed
 35# Inputs are compared against this same array
 36# array.array('H', [x]) must be used for IR pulse arrays when using pulseio
 37# indented to multiple lines so its easier to see
 38pulse_A = array.array('H', [1000, 3800, 65000, 950, 300, 200, 300, 1000, 350, 175,
 39    275, 215, 275, 250, 275, 215, 275, 225, 275, 215, 275, 1000, 300, 225, 275,
 40    950, 300, 950, 300, 1000, 300, 950, 300, 250, 275, 700, 300, 950, 300, 450,
 41    300, 475, 300, 215, 275, 725, 300, 950, 300, 200, 300, 715, 325, 900, 315,
 42    425, 315, 1000, 65000])
 43pulse_B = array.array('H', [1000, 3800, 65000, 960, 300, 200, 300, 950, 350, 190,
 44    215, 245, 300, 225, 275, 225, 275, 215, 275, 200, 300, 700, 300, 200, 300,
 45    700, 300, 1000, 315, 675, 300, 1000, 300, 200, 300, 700, 300, 950, 300,
 46    950, 300, 700, 300, 700, 300, 450, 300, 475, 275, 715, 300, 225, 275, 450,
 47    300, 450, 300, 1000, 65000])
 48
 49# Fuzzy pulse comparison function. Fuzzyness is % error
 50def fuzzy_pulse_compare(pulse1, pulse2, fuzzyness=0.5):
 51    if len(pulse1) != len(pulse2):
 52        return False
 53    for i in range(len(pulse1)):
 54        threshold = int(pulse1[i] * fuzzyness)
 55        if abs(pulse1[i] - pulse2[i]) > threshold:
 56            return False
 57    return True
 58
 59
 60# serial print once when activated
 61print('IR Activated!')
 62
 63while True:
 64    # when A3 or A4 is Touched, send IR pulse
 65    # detection is paused then cleared and resumed after a short pause
 66    # this prevents reflected detection of own IR
 67    while cp.touch_A3:
 68        pulseIn.pause()  # pauses IR detection
 69        pulse.send(pulse_A)  # sends IR pulse
 70        time.sleep(.2)  # wait so pulses dont run together
 71        pulseIn.clear()  # clear any detected pulses to remove partial artifacts
 72        pulseIn.resume()  # resumes IR detection
 73    while cp.touch_A4:
 74        pulseIn.pause()
 75        pulse.send(pulse_B)
 76        time.sleep(.2)
 77        pulseIn.clear()
 78        pulseIn.resume()
 79# Wait for a pulse to be detected of desired length
 80    # our array is 59 bytes so anything shorter ignore
 81    while len(pulseIn) >= 59:
 82        pulseIn.pause()
 83# converts pulseIn raw data into useable array
 84        detected = array.array('H', [pulseIn[x] for x in range(len(pulseIn))])
 85#        print(len(pulseIn))
 86#        print(detected)
 87
 88    # Got a pulse, now compare against stored pulse_A and pulse_B
 89        if fuzzy_pulse_compare(pulse_A, detected):
 90            print('Received A3 control A!')
 91            t_end = time.monotonic() + 0.8  # saves time 2 seconds in the future
 92            while time.monotonic() < t_end:
 93                cp.pixels.fill(OFF)
 94                for x in range(6):
 95                    cp.pixels[Neo_smiley_face[x]] = (color_got_saved)
 96                cp.play_file("yelling-yeah.wav")
 97                time.sleep(0.2)
 98
 99                if counter < 10 and counter > 0:
100                    counter = counter-1
101                    lifes = 10-counter
102                cp.pixels.fill(OFF)
103
104        else:
105            for i in range(lifes):
106                cp.pixels[full_led[i]] = myID_color
107                pulseIn.clear()
108                pulseIn.resume()
109
110        if fuzzy_pulse_compare(pulse_B, detected):
111            print('Received A4 control B !')
112            t_end = time.monotonic() + 0.8
113            while time.monotonic() < t_end:
114                print(counter)
115                print(lifes)
116                cp.pixels.fill(OFF)
117                cp.pixels.fill(color_got_hit)
118
119                cp.play_file("failure.wav")
120                time.sleep(0.2)
121                counter = counter+1
122                lifes = 10-counter
123                if lifes < 1:
124                    sys.exit()
125                cp.pixels.fill(OFF)
126                for i in range(lifes):
127                    cp.pixels[full_led[i]] = myID_color
128
129        else:
130            for i in range(lifes):
131                cp.pixels[full_led[i]] = myID_color
132                pulseIn.clear()
133                pulseIn.resume()
134
135        time.sleep(.1)
136        pulseIn.clear()
137        pulseIn.resume()