keypad_demux – Support for scanning key matrices that use a demultiplexer
The keypad_demux module provides native support to scan a matrix of keys or buttons
where either the row or column axis is controlled by a demultiplexer or decoder IC
such as the 74LS138 or 74LS238. In this arrangement a binary input value
determines which column (or row) to select, thereby reducing the number of input pins.
For example the input 101 would select line 5 in the matrix.
Set columns_to_anodes to False with a non-inverting demultiplexer
which drives the selected line high.
Set transpose to True if columns are multiplexed rather than rows.
Available on these boards
- class keypad_demux.DemuxKeyMatrix(row_addr_pins: Sequence[microcontroller.Pin], column_pins: Sequence[microcontroller.Pin], columns_to_anodes: bool = True, transpose: bool = False, interval: float = 0.02, max_events: int = 64, debounce_threshold: int = 1)
Manage Cardputer 2D matrix of keys with a demultiplexer to drive rows and pins on columns.
Available on these boards
- 0xCB Gemini
- 0xCB Helios
- 42. Keebs Frood
- 8086 RP2040 Interfacer
- 8086 USB Interposer
- ARAMCON Badge 2019
- ARAMCON2 Badge
- ATMegaZero ESP32-S2
- Adafruit CLUE nRF52840 Express
- Adafruit Circuit Playground Bluefruit
- Adafruit Feather Bluefruit Sense
- Adafruit Feather ESP32 V2
- Adafruit Feather ESP32-C6 4MB Flash No PSRAM
- Adafruit Feather ESP32-S2 Reverse TFT
- Adafruit Feather ESP32-S2 TFT
- Adafruit Feather ESP32-S3 Reverse TFT
- Adafruit Feather ESP32-S3 TFT
- Adafruit Feather ESP32S2
- Adafruit Feather ESP32S3 4MB Flash 2MB PSRAM
- Adafruit Feather ESP32S3 No PSRAM
- Adafruit Feather HUZZAH32
- Adafruit Feather MIMXRT1011
- Adafruit Feather RP2040
- Adafruit Feather RP2040 Adalogger
- Adafruit Feather RP2040 CAN
- Adafruit Feather RP2040 DVI
- Adafruit Feather RP2040 Prop-Maker
- Adafruit Feather RP2040 RFM
- Adafruit Feather RP2040 Scorpio
- Adafruit Feather RP2040 ThinkInk
- Adafruit Feather RP2040 USB Host
- Adafruit Feather RP2350
- Adafruit Feather STM32F405 Express
- Adafruit Feather nRF52840 Express
- Adafruit Floppsy RP2040
- Adafruit FunHouse
- Adafruit HUZZAH32 Breakout
- Adafruit ItsyBitsy ESP32
- Adafruit ItsyBitsy RP2040
- Adafruit ItsyBitsy nRF52840 Express
- Adafruit KB2040
- Adafruit LED Glasses Driver nRF52840
- Adafruit Macropad RP2040
- Adafruit MagTag
- Adafruit MatrixPortal S3
- Adafruit Metro ESP32S2
- Adafruit Metro ESP32S3
- Adafruit Metro RP2040
- Adafruit Metro RP2350
- Adafruit Metro nRF52840 Express
- Adafruit Mini Sparkle Motion
- Adafruit QT Py ESP32 PICO
- Adafruit QT Py ESP32-S3 4MB Flash 2MB PSRAM
- Adafruit QT Py ESP32-S3 no psram
- Adafruit QT Py ESP32S2
- Adafruit QT Py RP2040
- Adafruit QT2040 Trinkey
- Adafruit Sparkle Motion
- Adafruit Vindie S2
- Adafruit-Qualia-S3-RGB666
- Ai Thinker ESP32-CAM
- Archi RP2040
- Arduino Nano 33 BLE
- Arduino Nano 33 BLE Rev2
- Arduino Nano ESP32
- Arduino Nano RP2040 Connect
- Artisense Reference Design RD00
- AtelierDuMaker nRF52840 Breakout
- AutosportLabs-ESP32-CAN-X2
- BARDUINO 4.0.2
- BBQ20KBD
- BLE-SS dev board Multi Sensor
- BLING!
- BLOK
- BPI-Bit-S2
- BPI-Leaf-S3
- BPI-PicoW-S3
- BastBLE
- BastWiFi
- Bee-Data-Logger
- Bee-Motion-S3
- Bee-S3
- BlizzardS3
- BlueMicro840
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- COSMO-Pico
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- Challenger NB RP2040 WiFi
- Challenger RP2040 LTE
- Challenger RP2040 LoRa
- Challenger RP2040 SD/RTC
- Challenger RP2040 SubGHz
- Challenger RP2040 WiFi
- Challenger RP2040 WiFi/BLE
- Challenger+ RP2350 BConnect
- Challenger+ RP2350 WiFi6/BLE5
- CircuitART Zero S3
- ColumbiaDSL-Sensor-Board-V1
- CrumpS2
- Cytron EDU PICO W
- Cytron IRIV IO Controller
- Cytron MOTION 2350 Pro
- Cytron Maker Feather AIoT S3
- Cytron Maker Nano RP2040
- Cytron Maker Pi RP2040
- Cytron Maker Uno RP2040
- DFRobot FireBeetle 2 ESP32-S3
- Datanoise PicoADK
- Datanoise PicoADK V2
- Deneyap Kart
- Deneyap Kart 1A
- Deneyap Kart 1A v2
- Deneyap Mini
- Deneyap Mini v2
- Diodes Delight Piunora
- E-Fidget
- ELECFREAKS PICO:ED
- ES3ink
- ESP 12k NodeMCU
- ESP32 Devkit V1
- ESP32-C6-DevKitC-1-N8
- ESP32-C6-DevKitM-1
- ESP32-H2-DevKitM-1
- ESP32-P4 Stamp XL
- ESP32-P4-Function-EV
- ESP32-S2-DevKitC-1-N4
- ESP32-S2-DevKitC-1-N4R2
- ESP32-S2-DevKitC-1-N8R2
- ESP32-S3-Box-2.5
- ESP32-S3-Box-Lite
- ESP32-S3-DevKitC-1-N16
- ESP32-S3-DevKitC-1-N32R8
- ESP32-S3-DevKitC-1-N8
- ESP32-S3-DevKitC-1-N8R2
- ESP32-S3-DevKitC-1-N8R8
- ESP32-S3-DevKitC-1-N8R8-with-HACKTABLET
- ESP32-S3-DevKitM-1-N8
- ESP32-S3-EYE
- ESP32-S3-USB-OTG-N8
- ESP8684-DevKitC-02-N4
- Electrolama minik
- Electronut Labs Blip
- Electronut Labs Papyr
- EncoderPad RP2040
- Espressif ESP32 DevKitc V4 WROOM-32E
- Espressif ESP32 DevKitc V4 WROVER
- Espressif ESP32 TTGO T8 v1.7
- Espressif ESP32-LyraT
- Espressif-ESP32-S3-LCD-EV-Board
- Espressif-ESP32-S3-LCD-EV-Board_v1.5
- Espruino Bangle.js 2
- Espruino Wifi
- Feather MIMXRT1011
- Feather MIMXRT1062
- FeatherS2
- FeatherS2 Neo
- FeatherS2 PreRelease
- FeatherS3
- FeatherS3 Neo
- Fig Pi
- Flipper Zero Wi-Fi Dev
- Fomu
- Franzininho WIFI w/Wroom
- Franzininho WIFI w/Wrover
- Freenove ESP32-WROVER-DEV-CAM
- Gravitech Cucumber M
- Gravitech Cucumber MS
- Gravitech Cucumber R
- Gravitech Cucumber RS
- HEIA-FR Picomo V2
- HEIA-FR Picomo V3
- HMI-DevKit-1.1
- Hack Club Sprig
- Hardkernel Odroid Go
- Heltec ESP32-S3-WIFI-LoRa-V3
- Heltec Wireless Paper
- HexKyS2
- HiiBot BlueFi
- IMXRT1010-EVK
- IMXRT1015-EVK
- IkigaiSense Vita nRF52840
- IoTs2
- Kaluga 1
- LILYGO T-DISPLAY
- LILYGO T-DISPLAY S3 v1.2
- LILYGO T-Deck (Plus)
- LILYGO T-Display S3 Pro
- LILYGO T-Watch-S3
- LILYGO TEMBED ESP32S3
- LILYGO TTGO T-DISPLAY v1.1
- LILYGO TTGO T-DISPLAY v1.1 4M
- LILYGO TTGO T8 ESP32-S2
- LILYGO TTGO T8 ESP32-S2 w/Display
- LOLIN S3 16MB Flash 8MB PSRAM
- LOLIN S3 MINI 4MB Flash 2MB PSRAM
- LOLIN S3 PRO 16MB Flash 8MB PSRAM
- Lilygo T-watch 2020 V3
- M5Stack Atom Echo
- M5Stack Atom Lite
- M5Stack Atom Matrix
- M5Stack Atom U
- M5Stack AtomS3
- M5Stack AtomS3 Lite
- M5Stack AtomS3U
- M5Stack Cardputer
- M5Stack Core Basic
- M5Stack Core Fire
- M5Stack Core2
- M5Stack CoreS3
- M5Stack Dial
- M5Stack M5Paper
- M5Stack Stamp-S3
- M5Stack Stick C
- M5Stack Stick C Plus
- M5Stack Stick C Plus2
- M5Stack Timer Camera X
- MDBT50Q-DB-40
- MDBT50Q-RX Dongle
- MORPHEANS MorphESP-240
- MagiClick S3 N4R2
- Maker Go ESP32C6 Supermini
- Maker badge by Czech maker
- MakerDiary nRF52840 MDK
- MakerDiary nRF52840 MDK USB Dongle
- MakerFabs-ESP32-S3-Parallel-TFT-With-Touch-7inch
- Makerdiary M60 Keyboard
- Makerdiary Pitaya Go
- Makerdiary nRF52840 Connect Kit
- Makerdiary nRF52840 M.2 Developer Kit
- Maple Computing Elite-Pi
- Melopero Shake RP2040
- Metro MIMXRT1011
- MicroDev microS2
- MixGo CE
- Music Thing Modular Workshop Computer
- NUCLEO STM32F746
- NUCLEO STM32F767
- NUCLEO STM32H743
- NanoS3
- Neuron
- NodeMcu-ESP32-C2
- OMGS3
- OPENMV-H7 R1
- Oak Dev Tech BREAD2040
- Oak Dev Tech Cast-Away RP2040
- Oak Dev Tech PixelWing ESP32S2
- Oak Dev Tech RPGA Feather
- Open Hardware Summit 2020 Badge
- Oxocard Artwork
- Oxocard Connect
- Oxocard Galaxy
- Oxocard Science
- PCA10056 nRF52840-DK
- PCA10059 nRF52840 Dongle
- PYB LR Nano V2
- Pajenicko PicoPad
- Particle Argon
- Particle Boron
- Particle Xenon
- PillBug
- Pimoroni Badger 2040
- Pimoroni Badger 2040 W
- Pimoroni Inky Frame 5.7
- Pimoroni Inky Frame 7.3
- Pimoroni Interstate 75
- Pimoroni Keybow 2040
- Pimoroni Motor 2040
- Pimoroni PGA2040
- Pimoroni PGA2350
- Pimoroni Pico DV Base W
- Pimoroni Pico LiPo (16MB)
- Pimoroni Pico LiPo (4MB)
- Pimoroni Pico Plus 2
- Pimoroni Pico Plus 2 W
- Pimoroni Pico dv Base
- Pimoroni PicoSystem
- Pimoroni Plasma 2040
- Pimoroni Plasma 2040W
- Pimoroni Plasma 2350
- Pimoroni Plasma 2350W
- Pimoroni Servo 2040
- Pimoroni Tiny 2040 (2MB)
- Pimoroni Tiny 2040 (8MB)
- Pimoroni Tiny 2350
- Pimoroni Tiny FX
- ProS3
- PyKey 18 Numpad
- PyKey 44 Ergo
- PyKey 60
- PyKey 87 TKL
- PyboardV1_1
- RF.Guru RP2040
- RGBTouch Mini
- RP2.65-F
- RP2040 Stamp
- RP2350 Stamp
- RP2350 Stamp XL
- Raspberry Breadstick
- Raspberry Pi 4B
- Raspberry Pi Compute Module 4
- Raspberry Pi Compute Module 4 IO Board
- Raspberry Pi Pico
- Raspberry Pi Pico 2
- Raspberry Pi Pico 2 W
- Raspberry Pi Pico W
- Raspberry Pi Zero
- Raspberry Pi Zero 2W
- Raspberry Pi Zero W
- S2Mini
- S2Pico
- SQFMI Watchy
- SSCI ISP1807 Dev Board
- SSCI ISP1807 Micro Board
- ST STM32F746G Discovery
- STM32F411E_DISCO
- STM32F412G_DISCO
- STM32F4_DISCO
- Saola 1 w/Wroom
- Saola 1 w/Wrover
- Seeed XIAO nRF52840 Sense
- Seeed Xiao ESP32-C6 4MB Flash 512KB SRAM
- Seeed Xiao ESP32-S3 Sense
- Seeeduino XIAO RP2040
- Seeeduino XIAO RP2350
- Silicognition LLC RP2040-Shim
- SparkFun MicroMod RP2040 Processor
- SparkFun MicroMod nRF52840 Processor
- SparkFun Pro Micro RP2040
- SparkFun Pro Micro RP2350
- SparkFun Pro nRF52840 Mini
- SparkFun STM32 MicroMod Processor
- SparkFun Teensy MicroMod Processor
- SparkFun Thing Plus - RP2040
- SparkFun Thing Plus - STM32
- SparkFun Thing Plus RP2350
- Sunton-ESP32-8048S050
- Sunton-ESP32-8048S070
- SuperMini NRF52840
- Swan R5
- TG-Watch
- THUNDERPACK_v11
- THUNDERPACK_v12
- TTGO T8 ESP32-S2-WROOM
- Targett Module Clip w/Wroom
- Targett Module Clip w/Wrover
- Teensy 4.0
- Teensy 4.1
- Teknikio Bluebird
- ThingPulse Pendrive S3
- TinkeringTech ScoutMakes Azul
- TinyC6
- TinyPICO
- TinyPICO Nano
- TinyS2
- TinyS3
- TinyWATCH S3
- VCC-GND Studio YD RP2040
- VCC-GND YD-ESP32-S3 (N16R8)
- VCC-GND YD-ESP32-S3 (N8R8)
- VIDI X V1.1
- W5100S-EVB-Pico
- W5100S-EVB-Pico2
- W5500-EVB-Pico
- WK-50 Trackball Keyboard
- WSC-1450
- WarmBit BluePixel nRF52840
- Waveshare ESP32-C6 LCD 1.47
- Waveshare ESP32-S2-Pico
- Waveshare ESP32-S2-Pico-LCD
- Waveshare ESP32-S3-ETH
- Waveshare ESP32-S3-GEEK
- Waveshare ESP32-S3-Matrix
- Waveshare ESP32-S3-Pico
- Waveshare ESP32-S3-Tiny
- Waveshare ESP32-S3-Zero
- Waveshare ESP32S3 LCD 1.28
- Waveshare RP2040-GEEK
- Waveshare RP2040-LCD-0.96
- Waveshare RP2040-LCD-1.28
- Waveshare RP2040-One
- Waveshare RP2040-PiZero
- Waveshare RP2040-Plus (16MB)
- Waveshare RP2040-Plus (4MB)
- Waveshare RP2040-TOUCH-LCD-1.28
- Waveshare RP2040-Tiny
- Waveshare RP2040-Zero
- Waveshare RP2350-GEEK
- Waveshare RP2350-LCD-0.96
- Waveshare RP2350-LCD-1.28
- Waveshare RP2350-One
- Waveshare RP2350-Plus
- Waveshare RP2350-TOUCH-LCD-1.28
- Waveshare RP2350-Tiny
- Waveshare RP2350-Zero
- WeAct ESP32-C6 (4MB)
- WeAct ESP32-C6 (8MB)
- WeAct Studio Pico
- WeAct Studio Pico 16MB
- WeMos LOLIN32 Lite
- WisdPi Ardu2040M
- WisdPi Tiny RP2040
- cezerio dev ESP32C6
- iLabs Challenger 840
- iMX RT 1020 EVK
- iMX RT 1040 EVK
- iMX RT 1050 EVKB
- iMX RT 1060 EVK
- iMX RT 1060 EVKB
- iMX RT1011 Nano Kit
- nanoESP32-S2 w/Wrover
- nanoESP32-S2 w/Wroom
- nice!nano
- nullbits Bit-C PRO
- senseBox MCU-S2 ESP32S2
- splitkb.com Liatris
- stm32f411ce-blackpill
- stm32f411ce-blackpill-with-flash
- sunton_esp32_2432S024C
- sunton_esp32_2432S028
- sunton_esp32_2432S032C
- takayoshiotake Octave RP2040
- uGame22
Create a
keypad.Keysobject that will scan the key matrix attached to the given row and column pins. There should not be any external pull-ups or pull-downs on the matrix:DemuxKeyMatrixenables internal pull-ups or pull-downs on the pins as necessary.The keys are numbered sequentially from zero. A key number can be computed by
row * len(column_pins) + column.An
keypad.EventQueueis created when this object is created and is available in theeventsattribute.- Parameters:
row_addr_pins (Sequence[microcontroller.Pin]) – The pins attached to the rows demultiplexer. If your columns are multiplexed, set
transposetoTrue.column_pins (Sequence[microcontroller.Pin]) – The pins attached to the columns.
columns_to_anodes (bool) – Default
True. If the matrix uses diodes, the diode anodes are typically connected to the column pins with the cathodes connected to the row pins. This implies an inverting multiplexer that drives the selected row pin low. If your diodes are reversed, with a non-inverting multiplexer that drives the selected row high, setcolumns_to_anodestoFalse. IftransposeisTruethe sense of columns and rows are reversed here.transpose (bool) – Default
False. If your matrix is multiplexed on columns rather than rows, settransposetoTrue. This swaps the meaning ofrow_addr_pinstocolumn_addr_pins;column_pinstorow_pins; andcolumns_to_anodestorows_to_anodes.interval (float) – Scan keys no more often than
intervalto allow for debouncing.intervalis in float seconds. The default is 0.020 (20 msecs).max_events (int) – maximum size of
eventskeypad.EventQueue: maximum number of key transition events that are saved. Must be >= 1. If a new event arrives when the queue is full, the oldest event is discarded.debounce_threshold (int) – Emit events for state changes only after a key has been in the respective state for
debounce_thresholdtimes on average. Successive measurements are spaced apart byintervalseconds. The default is 1, which resolves immediately. The maximum is 127.
- __enter__() DemuxKeyMatrix
No-op used by Context Managers.
- __exit__() None
Automatically deinitializes when exiting a context. See Lifetime and ContextManagers for more info.
- reset() None
Reset the internal state of the scanner to assume that all keys are now released. Any key that is already pressed at the time of this call will therefore immediately cause a new key-pressed event to occur. For instance, if you call
reset()immediately after creating aDemuxKeyMatrixobject at the beginning of your program, the events it generates will let you determine which keys were being held down at program start.
- key_number_to_row_column(key_number: int) Tuple[int]
Return the row and column for the given key number. The row is
key_number // len(column_pins). The column iskey_number % len(column_pins).- Returns:
(row, column)- Return type:
Tuple[int]
- row_column_to_key_number(row: int, column: int) int
Return the key number for a given row and column. The key number is
row * len(column_pins) + column.
- events: keypad.EventQueue
The
keypad.EventQueueassociated with thiskeypad.Keysobject. (read-only)