Warm-up Exercises:

• Make your board count button presses in the serial console (remember edge detection?)
• Print a poem line-by-line in the console.
• Use buttons to light up neopixels.
• Create an animation in the neopixels.
• Can you make a game?

Things you remember from last time?

Today's rough agenda:

• Microcontroller Time
• Animations & Interactions
• Break
• Analog vs Digital
• Capacitive Touch

Quick reminders:

• Don't put boards on metal
• Code lives on the board

If I ask you to make your board say "hello" every 5 seconds, how would you do it?

You might do it this way:

import time 

while True:
    print("hello")
    time.sleep(5)

time.time() - number of seconds since Jan 1, 1970

time.monotonic() - an ever-increasing value per "tick"

time.monotonic_ns() - like the above, but in nanoseconds

time.localtime() theoretically should give you the current time locally ...

but the reality is it doesn't work.

Exercise: Create a stopwatch using your board.

Challenge: Have your board blink the number of seconds that elapse between button presses.

So why is this important?

Try this:

Make an animation that spins a pixel around in a circle on your board, without using time.sleep.

Then, have that animation pause when you hit a button, and unpause when you hit it again.

import time 
import board
import digitalio

button = digitalio.DigitalInOut(board.BUTTON_A)
button.switch_to_input(pull=digitalio.Pull.DOWN)

while True:
    print((int(button.value),0,0))
    time.sleep(0.2)

"Digital" doesn't just refer to how we read from a button, it can also be how we write to it.

It can be both input and output.

Remember our LED?

import time 
import board
import digitalio

led = digitalio.DigitalInOut(board.LED)

while True:
    led.value = True
    time.sleep(1)
    led.value = False
    time.sleep(1)

Analog In Basic Example

import time
import board
import analogio

analogin = analogio.AnalogIn(board.A1)

while True:
    print((analogin.value,0,0))
    time.sleep(0.1)

We get lots of values!

How can you use these values? What do you need to do to make these values useful?

Potentiometer with voltage helper

Capacitive Touch Example Code

import time
import board
import touchio

touch_A1 = touchio.TouchIn(board.A1)

while True:
    print((int(touch_A1.value),0,0))

    time.sleep(0.01)

Wait a second ... doesn't this look like digital?

change touch_A1.value → touch_A1.raw_value

So you have both; the Capacitive Touch library technically reads in analog, but it gives you a nice "touched-or-not-touched" value too.

touch_A1.raw_value ← real readings

touch_A1.value ← treated like digital

Exercise: Test out the Capacitive Touch inputs!

• Read more of the capacitive touch pads. Use them together!
• Can you use both the value and raw_value together?
• Challenge: Try putting edge detection into play here ... how would you do that with an analog value?

Example code for later reference

cap touch edge detection (regular value), two directions