diagram.json

# micropython-encoder-knob
very simple lightweight encoder knob library with button support



README-encoder.md

#
# Minimal library for interfacing with encoder knobs such as the CYT1100
#
import machine
from micropython import const


# ENCODER
# This Library assumes you are using a 3 pin encoder (2 outputs, and 1 ground).
# The two outputs will be internally pulled up by the microcontroller. If the
# Note: you can change the encoder direction by swapping the two output pins.


# BUTTON
# Some encoder knobs also allow for a down press (momentary button). These 
# typically include two pins on the other side of the encoder. This library
# assumes one of them will be grounded and the other will be internally pulled
# up by the microcrontroller.



class EncoderKnob(object):
    """
    Encoder Knob class. Handles reading the knob rotation and button press
    """
    def __init__(self, clk_pin, data_pin, btn_pin=None, rotary_callback=None, btn_callback=None):
        """
        @param clk_pin: one of the output pins from the encoder (will be internally pulled up)
        @param data_pin: the other output pin of the encoder (will be internally pulled up)
        @param btn_pin: (optional) if the encoder also includes a button (will be internally pulled up)
        @param rotary_callback: (optional) Recommended, callback function accepting a single negative
                                or positive integer for how much the knob rotated.
        @param btn_callback: (optional) Recommended, callback accepting no arguments. Called every time
                             the button is pressed (falling edge)
        """
        self.RotaryCallback = rotary_callback
        self.ButtonCallback = btn_callback

        self.Clk = machine.Pin(clk_pin, machine.Pin.IN, machine.Pin.PULL_UP)
        self.Data = machine.Pin(data_pin, machine.Pin.IN, machine.Pin.PULL_UP)
        if btn_pin:
            self.Button = machine.Pin(btn_pin, machine.Pin.IN, machine.Pin.PULL_UP)
            self.Button.irq(handler=self._handleButton, trigger=machine.Pin.IRQ_FALLING)
        self.RawValue = 0
        self.KnobValue = 0

        self.LastState = 0

        self.Clk.irq(handler=self._handlePins, trigger=machine.Pin.IRQ_RISING | machine.Pin.IRQ_FALLING)
        self.Data.irq(handler=self._handlePins, trigger=machine.Pin.IRQ_RISING | machine.Pin.IRQ_FALLING)

    def _handlePins(self, pin):
        state = self.Clk.value()
        change = 0
        if state != self.LastState:
            if self.Data.value() != state:
                change = 1
            else:
                change = -1
        
            self.RawValue += change
            self.KnobValue = int(self.RawValue / 2)

            # The CYT1100 knob reads 2 pulses per click of the wheel
            if change != 0 and self.RawValue % 2 == 0 and self.RotaryCallback:
                self.RotaryCallback(change)
        
        self.LastState = state
    
    def _handleButton(self, pin):
        if self.ButtonCallback:
            self.ButtonCallback()
    
    def value(self):
        """
        @return: current value of the encoder
        """
        return self.KnobValue


encoder.py

import time
from encoder import EncoderKnob


def rotated(amount):
    print("Knob Rotated ", amount)

def pressed():
    print("Button Pressed")

def test():
    enc = EncoderKnob(18, 19, btn_pin=4, rotary_callback=rotated, btn_callback=pressed)
    while True:
        time.sleep(1)
        print()
        print("Knob Value: ", enc.value())
        print()

#
# Entry point
#
print("Turn the knob and press the button...")
test()

test.py

# MicroPython TM1637

A MicroPython library for quad 7-segment LED display modules using the TM1637 LED driver.

![demo](docs/demo.jpg)

### Installation

Using mip via mpremote:

```bash
$ mpremote mip install github:mcauser/micropython-tm1637
```

Using mip directly on a WiFi capable board:

```python
>>> import mip
>>> mip.install("github:mcauser/micropython-tm1637")
```

Manual installation:

Copy `tm1637.py` to the root directory of your device.

## Examples

**Basic usage**

```python
import tm1637
from machine import Pin
tm = tm1637.TM1637(clk=Pin(5), dio=Pin(4))

# all LEDS on "88:88"
tm.write([127, 255, 127, 127])

# all LEDS off
tm.write([0, 0, 0, 0])

# show "0123"
tm.write([63, 6, 91, 79])

# show "COOL"
tm.write([0b00111001, 0b00111111, 0b00111111, 0b00111000])

# show "HELP"
tm.show('help')

# display "dEAd", "bEEF"
tm.hex(0xdead)
tm.hex(0xbeef)

# show "12:59"
tm.numbers(12, 59)

# show "-123"
tm.number(-123)

# show temperature '24*C'
tm.temperature(24)
```

For more detailed examples, see [tm1637_test.py](tm1637_test.py)

# Seven Segment Font

They are called 7-segment displays as there are 7 LEDs for each digit (segment).
One byte (7 lower bits) for each segment. The 8th bit (MSB) is for the colon and only on the 2nd segment.

```
      A
     ---
  F |   | B   *
     -G-      H (on 2nd segment)
  E |   | C   *
     ---
      D

  HGFEDCBA
0b01101101 = 0x6D = 109 = show "5"
```

Display | Bin        | Hex  | Dec
------- | ---------- | ---- | ---
0       | 0b00111111 | 0x3F | 63
1       | 0b00000110 | 0x06 | 6
2       | 0b01011011 | 0x5B | 91
3       | 0b01001111 | 0x4F | 79
4       | 0b01100110 | 0x66 | 102
5       | 0b01101101 | 0x6D | 109
6       | 0b01111101 | 0x7D | 125
7       | 0b00000111 | 0x07 | 7
8       | 0b01111111 | 0x7F | 127
9       | 0b01101111 | 0x6F | 111
A       | 0b01110111 | 0x77 | 119
b       | 0b01111100 | 0x7C | 124
C       | 0b00111001 | 0x39 | 57
d       | 0b01011110 | 0x5E | 94
E       | 0b01111001 | 0x79 | 121
F       | 0b01110001 | 0x71 | 113
G       | 0b00111101 | 0x3D | 61
H       | 0b01110110 | 0x76 | 118
I       | 0b00000110 | 0x06 | 6
J       | 0b00011110 | 0x1E | 30
K       | 0b01110110 | 0x76 | 118
L       | 0b00111000 | 0x38 | 56
M       | 0b01010101 | 0x55 | 85
n       | 0b01010100 | 0x54 | 84
O       | 0b00111111 | 0x3F | 63
P       | 0b01110011 | 0x73 | 115
q       | 0b01100111 | 0x67 | 103
r       | 0b01010000 | 0x50 | 80
S       | 0b01101101 | 0x6D | 109
t       | 0b01111000 | 0x78 | 120
U       | 0b00111110 | 0x3E | 62
v       | 0b00011100 | 0x1C | 28
W       | 0b00101010 | 0x2A | 42
X       | 0b01110110 | 0x76 | 118
y       | 0b01101110 | 0x6E | 110
Z       | 0b01011011 | 0x5B | 91
blank   | 0b00000000 | 0x00 | 0
\-      | 0b01000000 | 0x40 | 64
\*      | 0b01100011 | 0x63 | 99

# Methods

Get or set brightness.
```python
brightness(val=None)
```

Write one or more segments at a given offset.
```python
write(segments, pos=0)
```

Convert a single hex digit (0x00-0x0f) to a segment.
```python
encode_digit(digit)
```

Convert a string to a list of segments.
```python
encode_string(string)
```

Convert a single character to a segment.
```python
encode_char(char)
```

Display a number in hexadecimal format 0000 through FFFF.
```python
hex(val)
```

Display a number -999 through 9999, right aligned.
```python
number(num)
```

Display 2 independent numbers on either side of the (optional) colon, with leading zeros.
```python
numbers(num1, num2, colon=True)
```

Display a temperature -9 through 99 followed by degrees C.
```python
temperature(num)
```

Show a string on the display.
Shorthand for write(encode_string()).
Limited to first 4 characters.
```python
show(string, colon=False)
```

Display a string on the display, scrolling from the right to left, speed adjustable.
String starts off-screen and scrolls until off-screen at 4 FPS by default.
```python
scroll(string, delay=250)
```

## Modules

* [Grove 4 Digit Display](https://www.seeedstudio.com/Grove-4-Digit-Display.html)
* [RobotDyn 4-digit LED Display Tube](https://www.aliexpress.com/item/32795908218.html)
* [RobotDyn 6-digit LED Display Tube](https://www.aliexpress.com/item/32800127265.html)
* [Generic TM1637 LED Display Module](https://www.aliexpress.com/item/32657932650.html)

For example, the [Grove - 4 Digit Display module](http://wiki.seeed.cc/Grove-4-Digit_Display/)

## Connections

`CLK` and `DIO` are bit-banged. You can use any GPIO.

4 Digit Display | TinyPICO | Pi Pico | WeMos D1 Mini
--------------- | ---------| ------- | -------------
CLK             | IO18     | IO27    | D1 (GPIO5)
DIO             | IO23     | IO26    | D2 (GPIO4)
VCC             | 3V3      | 3V3     | 3V3/5V
GND             | GND      | GND     | G

## Links

* [micropython.org](http://micropython.org)
* [TM1637 datasheet](http://www.titanmec.com/index.php/en/project/download/id/302.html)
* [Titan Micro TM1637 product page](http://www.titanmec.com/index.php/en/project/view/id/302.html)
* [Nokia 5110 version](https://github.com/mcauser/MicroPython-ESP8266-Nokia-5110-Quad-7-segment)
* [BBC micro:bit version](https://github.com/mcauser/microbit-tm1637)

## License

Licensed under the [MIT License](http://opensource.org/licenses/MIT).


README-display.md

"""
MicroPython TM1637 quad 7-segment LED display driver
https://github.com/mcauser/micropython-tm1637

MIT License
Copyright (c) 2016-2023 Mike Causer

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
"""

__version__ = '1.3.0'

from micropython import const
from machine import Pin
from time import sleep_us, sleep_ms

TM1637_CMD1 = const(64)  # 0x40 data command
TM1637_CMD2 = const(192) # 0xC0 address command
TM1637_CMD3 = const(128) # 0x80 display control command
TM1637_DSP_ON = const(8) # 0x08 display on
TM1637_DELAY = const(10) # 10us delay between clk/dio pulses
TM1637_MSB = const(128)  # msb is the decimal point or the colon depending on your display

# 0-9, a-z, blank, dash, star
_SEGMENTS = bytearray(b'\x3F\x06\x5B\x4F\x66\x6D\x7D\x07\x7F\x6F\x77\x7C\x39\x5E\x79\x71\x3D\x76\x06\x1E\x76\x38\x55\x54\x3F\x73\x67\x50\x6D\x78\x3E\x1C\x2A\x76\x6E\x5B\x00\x40\x63')

class TM1637(object):
    """Library for quad 7-segment LED modules based on the TM1637 LED driver."""
    def __init__(self, clk, dio, brightness=7):
        self.clk = clk
        self.dio = dio

        if not 0 <= brightness <= 7:
            raise ValueError("Brightness out of range")
        self._brightness = brightness

        self.clk.init(Pin.OUT, value=0)
        self.dio.init(Pin.OUT, value=0)
        sleep_us(TM1637_DELAY)

        self._write_data_cmd()
        self._write_dsp_ctrl()

    def _start(self):
        self.dio(0)
        sleep_us(TM1637_DELAY)
        self.clk(0)
        sleep_us(TM1637_DELAY)

    def _stop(self):
        self.dio(0)
        sleep_us(TM1637_DELAY)
        self.clk(1)
        sleep_us(TM1637_DELAY)
        self.dio(1)

    def _write_data_cmd(self):
        # automatic address increment, normal mode
        self._start()
        self._write_byte(TM1637_CMD1)
        self._stop()

    def _write_dsp_ctrl(self):
        # display on, set brightness
        self._start()
        self._write_byte(TM1637_CMD3 | TM1637_DSP_ON | self._brightness)
        self._stop()

    def _write_byte(self, b):
        for i in range(8):
            self.dio((b >> i) & 1)
            sleep_us(TM1637_DELAY)
            self.clk(1)
            sleep_us(TM1637_DELAY)
            self.clk(0)
            sleep_us(TM1637_DELAY)
        self.clk(0)
        sleep_us(TM1637_DELAY)
        self.clk(1)
        sleep_us(TM1637_DELAY)
        self.clk(0)
        sleep_us(TM1637_DELAY)

    def brightness(self, val=None):
        """Set the display brightness 0-7."""
        # brightness 0 = 1/16th pulse width
        # brightness 7 = 14/16th pulse width
        if val is None:
            return self._brightness
        if not 0 <= val <= 7:
            raise ValueError("Brightness out of range")

        self._brightness = val
        self._write_data_cmd()
        self._write_dsp_ctrl()

    def write(self, segments, pos=0):
        """Display up to 6 segments moving right from a given position.
        The MSB in the 2nd segment controls the colon between the 2nd
        and 3rd segments."""
        if not 0 <= pos <= 5:
            raise ValueError("Position out of range")
        self._write_data_cmd()
        self._start()

        self._write_byte(TM1637_CMD2 | pos)
        for seg in segments:
            self._write_byte(seg)
        self._stop()
        self._write_dsp_ctrl()

    def encode_digit(self, digit):
        """Convert a character 0-9, a-f to a segment."""
        return _SEGMENTS[digit & 0x0f]

    def encode_string(self, string):
        """Convert an up to 4 character length string containing 0-9, a-z,
        space, dash, star to an array of segments, matching the length of the
        source string."""
        segments = bytearray(len(string))
        for i in range(len(string)):
            segments[i] = self.encode_char(string[i])
        return segments

    def encode_char(self, char):
        """Convert a character 0-9, a-z, space, dash or star to a segment."""
        o = ord(char)
        if o == 32:
            return _SEGMENTS[36] # space
        if o == 42:
            return _SEGMENTS[38] # star/degrees
        if o == 45:
            return _SEGMENTS[37] # dash
        if o >= 65 and o <= 90:
            return _SEGMENTS[o-55] # uppercase A-Z
        if o >= 97 and o <= 122:
            return _SEGMENTS[o-87] # lowercase a-z
        if o >= 48 and o <= 57:
            return _SEGMENTS[o-48] # 0-9
        raise ValueError("Character out of range: {:d} '{:s}'".format(o, chr(o)))

    def hex(self, val):
        """Display a hex value 0x0000 through 0xffff, right aligned."""
        string = '{:04x}'.format(val & 0xffff)
        self.write(self.encode_string(string))

    def number(self, num):
        """Display a numeric value -999 through 9999, right aligned."""
        # limit to range -999 to 9999
        num = max(-999, min(num, 9999))
        string = '{0: >4d}'.format(num)
        self.write(self.encode_string(string))

    def numbers(self, num1, num2, colon=True):
        """Display two numeric values -9 through 99, with leading zeros
        and separated by a colon."""
        num1 = max(-9, min(num1, 99))
        num2 = max(-9, min(num2, 99))
        segments = self.encode_string('{0:0>2d}{1:0>2d}'.format(num1, num2))
        if colon:
            segments[1] |= 0x80 # colon on
        self.write(segments)

    def temperature(self, num):
        if num < -9:
            self.show('lo') # low
        elif num > 99:
            self.show('hi') # high
        else:
            string = '{0: >2d}'.format(num)
            self.write(self.encode_string(string))
        self.write([_SEGMENTS[38], _SEGMENTS[12]], 2) # degrees C

    def show(self, string, colon=False):
        segments = self.encode_string(string)
        if len(segments) > 1 and colon:
            segments[1] |= 128
        self.write(segments[:4])

    def scroll(self, string, delay=250):
        segments = string if isinstance(string, list) else self.encode_string(string)
        data = [0] * 8
        data[4:0] = list(segments)
        for i in range(len(segments) + 5):
            self.write(data[0+i:4+i])
            sleep_ms(delay)


class TM1637Decimal(TM1637):
    """Library for quad 7-segment LED modules based on the TM1637 LED driver.

    This class is meant to be used with decimal display modules (modules
    that have a decimal point after each 7-segment LED).
    """

    def encode_string(self, string):
        """Convert a string to LED segments.

        Convert an up to 4 character length string containing 0-9, a-z,
        space, dash, star and '.' to an array of segments, matching the length of
        the source string."""
        segments = bytearray(len(string.replace('.','')))
        j = 0
        for i in range(len(string)):
            if string[i] == '.' and j > 0:
                segments[j-1] |= TM1637_MSB
                continue
            segments[j] = self.encode_char(string[i])
            j += 1
        return segments


tm1637.py

# MicroPython TM1637 quad 7-segment LED display driver examples

# WeMos D1 Mini -- 4 Digit Display
# D1 (GPIO5) ----- CLK
# D2 (GPIO4) ----- DIO
# 3V3 ------------ VCC
# G -------------- GND

import tm1637
from machine import Pin
tm = tm1637.TM1637(clk=Pin(5), dio=Pin(4))

# all LEDS on "88:88"
tm.write([127, 255, 127, 127])
tm.write(bytearray([127, 255, 127, 127]))
tm.write(b'\x7F\xFF\x7F\x7F')
tm.show('8888', True)
tm.numbers(88, 88, True)

# all LEDS off
tm.write([0, 0, 0, 0])
tm.show('    ')

# write to the 2nd and 3rd segments only
tm.write([119, 124], 1) # _Ab_
tm.write([124], 2) # __b_
tm.write([119], 1) # _A__

# display "0123"
tm.write([63, 6, 91, 79])
tm.write(bytearray([63, 6, 91, 79]))
tm.write(b'\x3F\x06\x5B\x4F')
tm.show('1234')
tm.number(1234)
tm.numbers(12, 34, False)

# display "4567"
tm.write([102, 109, 125, 7])
tm.write([102], 0) # 4___
tm.write([109], 1) # _5__
tm.write([125], 2) # __6_
tm.write([7], 3)   # ___7

# set middle two segments to "12", ie "4127"
tm.write([6, 91], 1) # _12_

# set last segment to "9", ie "4129"
tm.write([111], 3) # ___9

# walk through all possible LED combinations
from time import sleep_ms
for i in range(128):
    tm.number(i)
    tm.write([i])
    sleep_ms(100)

# show "AbCd"
tm.write([119, 124, 57, 94])
tm.show('abcd')

# show "COOL"
tm.write([0b00111001, 0b00111111, 0b00111111, 0b00111000])
tm.write([0x39, 0x3F, 0x3F, 0x38])
tm.write(b'\x39\x3F\x3F\x38')
tm.write([57, 63, 63, 56])
tm.show('cool')
tm.show('COOL')

# display "dEAd", "bEEF"
tm.hex(0xdead)
tm.hex(0xbeef)
tm.show('dead')
tm.show('Beef')

# show "12:59"
tm.numbers(12, 59)
tm.show('1259', True)

# show "-123"
tm.number(-123)
tm.show('-123')

# Show Help
tm.show('Help')
tm.write(tm.encode_string('Help'))
tm.write([tm.encode_char('H'), tm.encode_char('e'), tm.encode_char('l'), tm.encode_char('p')])

# Scroll Hello World from right to left
tm.scroll('Hello World') # 4 fps
tm.scroll('Hello World', 1000) # 1 fps

# Scroll all available characters
tm.scroll(list(tm1637._SEGMENTS))

# all LEDs dim
tm.brightness(0)

# all LEDs bright
tm.brightness(7)

# converts a digit 0-0x0f to a byte representing a single segment
# use write() to render the byte on a single segment
tm.encode_digit(0)
# 63

tm.encode_digit(8)
# 127

tm.encode_digit(0x0f)
# 113

# 15 or 0x0f generates a segment that can output a F character
tm.encode_digit(15)
# 113

tm.encode_digit(0x0f)
# 113

# used to convert a 1-4 length string to an array of segments
tm.encode_string('   1')
# bytearray(b'\x00\x00\x00\x06')

tm.encode_string('2   ')
# bytearray(b'[\x00\x00\x00')

tm.encode_string('1234')
# bytearray(b'\x06[Of')

tm.encode_string('-12-')
# bytearray(b'@\x06[@')

tm.encode_string('cafe')
# bytearray(b'9wqy')

tm.encode_string('CAFE')
# bytearray(b'9wqy')

tm.encode_string('a')
# bytearray(b'w\x00\x00\x00')

tm.encode_string('ab')
# bytearray(b'w|\x00\x00')

# used to convert a single character to a segment byte
tm.encode_char('1')
# 6

tm.encode_char('9')
# 111

tm.encode_char('-')
# 64

tm.encode_char('a')
# 119

tm.encode_char('F')
# 113

# display "dEAd", "bEEF", "CAFE" and "bAbE"
tm.hex(0xdead)
tm.hex(0xbeef)
tm.hex(0xcafe)
tm.hex(0xbabe)

# show "00FF" (hex right aligned)
tm.hex(0xff)

# show "   1" (numbers right aligned)
tm.number(1)

# show "  12"
tm.number(12)

# show " 123"
tm.number(123)

# show "9999" capped at 9999
tm.number(20000)

# show "  -1"
tm.number(-1)

# show " -12"
tm.number(-12)

# show "-123"
tm.number(-123)

# show "-999" capped at -999
tm.number(-1234)

# show "01:02"
tm.numbers(1, 2)

# show "0102"
tm.numbers(1, 2, False)

# show "-5:11"
tm.numbers(-5, 11)

# show "12:59"
tm.numbers(12, 59)

# show temperature '24*C'
tm.temperature(24)
tm.show('24*C')

# show temperature works for range -9 to +99
tm.temperature(-10) # LO*C
tm.temperature(-9)  # -9*C
tm.temperature(5)   #  5*C
tm.temperature(99)  # 99*C
tm.temperature(100) # HI*C


tm1637_test.py

## Keypad Library for Raspberry Pi Pico - DIYables_Pico_Keypad
This MicroPython library is designed for Raspberry Pi Pico to make it easy to use with keypad 3x4, keypad 4x4. It is easy to use for not only beginners but also experienced users... 

It is created by DIYables to work with DIYables Keypad, but also work with products from other brands. Please consider purchasing products from [DIYables Store on Amazon](https://amazon.com/diyables) to support our works.



Features
----------------------------
* Works with any Raspberry Pi Pico board.

Product Link
----------------------------
* [Keypad 3x4](https://diyables.io/products/keypad-3x4)
* [Keypad 4x4](https://diyables.io/products/keypad-4x4)


Available Functions
----------------------------
* __init__(keymap, row_pins, column_pins, num_rows, num_cols)
* get_key()
* set_debounce_time(time_ms)


Available Examples
----------------------------
* keypad_3x4.py
* keypad_4x4.py



Tutorials
----------------------------
* [Raspberry Pi Pico - Keypad 3x4](https://newbiely.com/tutorials/raspberry-pico/raspberry-pi-pico-keypad-3x4)
* [Raspberry Pi Pico - Keypad 4x4](https://newbiely.com/tutorials/raspberry-pico/raspberry-pi-pico-keypad-4x4)



References
----------------------------
* [Raspberry Pi Pico - Keypad Library](https://newbiely.com/tutorials/raspberry-pico/raspberry-pi-pico-keypad-library)


README-keypad.md

# DIYables_Pico_Keypad/__init__.py
from .DIYables_Pico_Keypad import Keypad


__init__.py

"""
This MicroPython library is designed for Raspberry Pi Pico to make it easy to use with keypad 3x4, keypad 4x4 

It is created by DIYables to work with DIYables products, but also work with products from other brands. Please consider purchasing products from [DIYables Store on Amazon](https://amazon.com/diyables) from to support our work.

Product Link:
- [Keypad 3x4](https://diyables.io/products/keypad-3x4)
- [Keypad 4x4](https://diyables.io/products/keypad-4x4)


Copyright (c) 2024, DIYables.io. All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:

- Redistributions of source code must retain the above copyright
  notice, this list of conditions and the following disclaimer.

- Redistributions in binary form must reproduce the above copyright
  notice, this list of conditions and the following disclaimer in the
  documentation and/or other materials provided with the distribution.

- Neither the name of the DIYables.io nor the names of its
  contributors may be used to endorse or promote products derived from
  this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY DIYABLES.IO "AS IS" AND ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL DIYABLES.IO BE LIABLE FOR ANY DIRECT,
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
"""

from machine import Pin, Timer
import time

class Keypad:
    def __init__(self, keymap, row_pins, column_pins, num_rows, num_cols):
        self._keymap = keymap
        self._row_pins = [Pin(pin, Pin.IN, Pin.PULL_UP) for pin in row_pins]
        self._column_pins = [Pin(pin, Pin.OUT) for pin in column_pins]
        self._num_rows = num_rows
        self._num_cols = num_cols
        self._prev_key = None
        self._debounce_time = 400  # default value is 300ms
        self._prev_time = 0
        
        # Set column pins to high
        for col_pin in self._column_pins:
            col_pin.value(1)

    def get_key(self):
        for col_index, col_pin in enumerate(self._column_pins):
            col_pin.value(0)  # Set current column to low
            for row_index, row_pin in enumerate(self._row_pins):
                if not row_pin.value():  # Active low
                    key = self._keymap[row_index * self._num_cols + col_index]
                    current_time = time.ticks_ms()
                    if self._prev_key != key or (self._prev_key == key and time.ticks_diff(current_time, self._prev_time) > self._debounce_time):
                        self._prev_key = key
                        self._prev_time = current_time
                        col_pin.value(1)  # Reset column pin
                        return key
            col_pin.value(1)  # Reset column pin
        return None

    def set_debounce_time(self, time_ms):
        self._debounce_time = time_ms


keypad.py

from keypad import Keypad
import time

NUM_ROWS = 4
NUM_COLS = 4

# Constants for GPIO pins
ROW_PINS = [13, 12, 11, 10]  # GPIO numbers for row pins
COLUMN_PINS = [9, 8, 7, 6]  # GPIO numbers for column pins

# Keymap corresponds to the layout of the keypad 4x4
KEYMAP = ['1', '2', '3', 'A',
          '4', '5', '6', 'B',
          '7', '8', '9', 'C',
          '*', '0', '#', 'D']

# Initialize the keypad
keypad = Keypad(KEYMAP, ROW_PINS, COLUMN_PINS, NUM_ROWS, NUM_COLS)
keypad.set_debounce_time(400) # 400ms, addjust it if it detects twice for single press

# Main loop to check for key presses
while True:
    key = keypad.get_key()
    if key:
        print("Key pressed:", key)
