SazkJere 8Pcs 12 Keys Matrix Array Membrane 3×4 Keypad Switch 7pin Keyboard Module Thin Film Switches for Arduino

Price: $9.49
(as of Feb 16, 2023 20:52:29 UTC – Details)

Product Description

Membrane Keypad

How keypad works & How to scan them?

The working principle is very simple. Pressing a button shorts one of row lines to one of column lines, allowing current to flow between them.

Keypad pins are divided into 2 groups: row and column.

The membrane is soft and has a removable paper backing to expose a strong adhesive so you can stick this on an enclosure and feed the cable through a slot.

This keypad work compatible with Arduino, ESP32, ESP8266, Raspberry Pi, or any 5V or 3.3V microcontroller.

Basic Description

1、Electronic Characteristics

Operating voltage: DC35V 1W

Operating current: 100mA

Contact resistance: 10Ω

Insulation resistance: 100MΩ (100VDC)

Dielectric withstand voltage: 250VRms (50-60Hz1min)

Contact jitter time: ≤5ms

2、Mechanical Properties

Service life: <500,000 times

Pin spacing standard: 2.54mm

Line thickness: ≤ 0.13mm

3、Environmental Parameters

Storage temperature: 15°C-35°C

Storage humidity: 70%-90%

Test temperature: 0°C-60°C 16H

Test humidity: 70%-90%

Atmospheric pressure: 86~106kDa

A microcontroller can scan these lines for a button-pressed state. To do this, it follows steps below.

Microcontroller sets all column and row lines to input.
Then, it picks a row and sets it HIGH.
After that, it checks column lines one at a time.
If column connection stays LOW, button on the row has not been pressed.
Microcontroller knows which row was set HIGH, and which column was detected HIGH when checked.
Finally, it knows which button was pressed that corresponds to detected row & column.

Note:

1. You can connect your keypad to any pins you would like. Be careful not to use serial pins (0 and 1) if you are using them for communication.

2. If key presses seem to take a long time to show up then you are probably using long delay()’s in your code. The same thing happens if you use too many small delay()s like delay(10).

3. Make sure you understand pin mappings and have keypad wired up to match. If you wired pins wrongly (and already soldered them in) then you may be able to fix it by redefining pins and/or keymap to make your keypad work.

1×4 Keypad

Keypad dimensions: 69*20mm

Length of cable: 87mm

5-pin 0.1″ pitch connector

Weight: 2.8g

3×4 Keypad

Keypad dimensions: 77*69mm

Length of cable: 85.5mm

7-pin 0.1″ pitch connector

Weight: 5g

4×4 Keypad

Keypad dimensions: 77*77mm

Length of cable: 84mm

8-pin 0.1″ pitch connector

Weight: 6.5g

Key Number
4 kyes
12 kyes
16 kyes
16 kyes
16 kyes

Pins
5 pins
7 pins
8 pins
8 pins
8 pins

Weight
3g
5g
6.5g
6.5g
6.5g

Cable length
87mm
85.5mm
84mm
84mm
84mm

Keypad dimension
69 x 20mm
77 x 69mm
77 x 77mm
77 x 77mm
77 x 77mm

Quantity
8pcs
8pcs
8pcs
6pcs
6pcs

★3X4 membrane switch button module 12 button button MCU external control keyboard expansion keyboard.
★Size: 77 x 69mm, total length: 85.5mm.
★Soft membrane with adhesive backing.
★Application: easy to use keypad for Arduino or Raspberry Pi project.
★You will get 8pcs 3X4 keypad Module.