Keypads are typically small 3x4 or 4x4 membrane button matrixes, used for phones or other devices needing numerical input. Similar to keyboards.

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Detect position of walkers along a path using IR transceivers

I am working on a project that the position of people walking along a path needs to be known. I'm a hobbyist so I don't know what options I may have. I want to use IR sender and receivers to ...
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1answer
91 views

Calculator with MSP430 in Assembly Language

I am programming a calculator in assembly language with the MSP430g2553. I have a 4x4 membrane keypad and an 2x16 LCD. I already can display numbers in the LCD with the keypad. The issue is that the ...
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0answers
72 views

4x4 Keypad with MSP430

I am connecting a 4x4 matrix keypad to a MSP430g2553. the MSP is already recognizing which key I am pressing but the output ascii code for each digit is wrong. For example if I press digit 5 in the ...
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0answers
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col not declared issue{Verilog}

I am having a problem here can't make this code compile. It is a 4x4 keypad scanner with a 20ms debouncer. It gives error "Error: 'col' has not been declared" Any suggestion? ...
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261 views
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1answer
56 views

4x4 keyboard matrix not generating unique keycodes

I have a 4x4 keybord matrix fsm scanner but it generates only high keycode setting all last 4 bits to 1 and second and fourth digits to high. Is there anything wrong in my code here? ...
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1answer
89 views

How to initiate a call on a GSM module from DTMF tones

Can someone tell me if it is possible to make a call from a GSM module using only the DTMF tones that a keypad puts out? If not, can someone explain how I would make the call using only the keypad, ...
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2answers
138 views

AVR sleep interrupt with keypad

I'd like to wake up my AVR whenever any button on the keypad is pressed. I am using Keypad.h library and simple 4x4 keypad made of buttons connected straight to AVR digital pins. Keypad itself works ...
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1answer
52 views

How do I include vibration in my keypad design [closed]

I am working on a project that includes the use of a Keypad. I intend to include a beep sound with a soft vibration when a key is pressed. I am yet to figure out how to generate such vibrations. I ...
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0answers
144 views

Using the right pins for keypad

I am using msp430g2553 microcontroller and a 4x4 HC543 keypad. I am using Energia IDE. I have connected the keypad from pin 2 through 9. My code is as follows: ...
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1answer
89 views

How can i connect 9 7segments to a 3x4 keypad using only diodes making each 7segment displays only one number? [closed]

I want to make each button in the keypad to display one number using only diodes without using any decoders or ic. thanks in advance
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1answer
81 views

How does my digital watch keypad work?

I have had the same digital watch model for many years. Although they inevitably break again and again, I continue to buy the same model (A Casio 53W). I now have quite a collection of them sitting on ...
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1answer
142 views

Pinout for a 6 pin 3x4 keypad

I have this old keypad sitting around, never used it because I could never figure out the pinout for it. Anyone know how this would be wired to something such as a picaxe/arduino? Front of the ...
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1answer
103 views

How to connect a 4x4 keypad without a microcontroller [duplicate]

I have the RS 331-304 4x4 keypad, and I need to connect it so that I can determine which key has been pressed without using a microcontroller. Is there a way I can connect it using logic gates? The ...
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1answer
1k views

Keypad Scanner Verilog code problem with state machine and column input

I am developing a Keypad both in hardware and Verilog using a DE2 Cyclone II board. I made a keypad using buttons (switches) that follows this schematic: The scanner works by setting the Column ...
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1answer
94 views

Pull down/pull up resistor for 5v input

I need to implement a pull-down resistor for a project, but I am unsure of what resistor to buy. My circuit deals with 5v inputs. Essentially, I am trying to make this: keypad scanner. Here is a ...
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3answers
246 views

Keypad to set a counter

Is there a way to use a standard Matrix Keypad to set a synchronous counter IC without having to use a micro controller?
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1answer
54 views

auto shift on keypad press in lcd using fujitsu F2MC-16LX MB90385 Series

We are using LCD and Keypad in our MCU and I was wondering how do i initialize my LCD so that every time there is a key press the display will automatically shift right and fill up the LCD as more ...
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1answer
131 views

PIC16F57 - problem implementing wake up signal on key stroke

I have designed a simple RC5 remote control using a PIC16F57 and the classic rows-columns scan over a 4x4 matrix keypad. The previous version of my firmware continuously scanned the keypad to find a ...
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3answers
294 views

Is there any way to interface 4x4 matrix keypad using 2 IO lines

I have two IO lines and wants to interface 4x4 matrix keypad. Using MUX ICs I need 4 IO lines. Is there any method to achieve it using 2 IOs?
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1answer
83 views

Can a keypad take any voltage?

I'm curious about keypads in regards to voltage. I have searched, and not found much related to this topic. It seems to me that keypads can take nearly any voltage so long as the voltage supplied is ...
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1answer
769 views

Lighting LED using keypad and microcontroller

So I am working with Gizduino (Arduino clone), keypad and led. What am I doing is getting the value of keypressed and then light up the led according to the value (eg., when I pressed 2 on the keypad ...
3
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3answers
8k views

4x4 keypad to Microcontroller

I have 8pin 4x4 keyapd, and i want to connect it to my microcontroller, I've search over the net but i can't see its pin configuration. I have a problem connecting it because of that can someone help ...
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1answer
2k views

Arduino pin descriptions

Hello, actually I am very new in electronics. Im using this as a reference in connecting lcd and 4x4 keypad in my my controller ( an arduino clone) Gizduino ATMEGA644 but I'm having a problem ...
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1answer
119 views

Is this circuit a viable implementation? [duplicate]

Following on from an earlier question where the implementation was flawed, can anyone advise if the below is a viable implementation of a circuit to handle a matrix keypad? The idea is that one ...
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3answers
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Interfacing Keypad to PIC16F877A

I am interfacing a 3X4 keypad to PIC16f877a uC on PORTD as: In the first half of the C program I have set first four pins to Input (From LSB-RD0) and others to Output and store the value in a ...
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1answer
495 views

Seeking 4x3 keypad for Atmel UC3 microprocessor

I was doing a combined project with a friend, with me on s/w and him on h/w. After a year of coding on my part & not much activity on his, he announced that he is "too busy" to continue. That ...
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2answers
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MPS430 Launchpad Keypad

I tried to use my MSP430G2553 launchpad with a keypad using http://www.pjrc.com/teensy/td_libs_Keypad.html http://bildr.org/2011/05/arduino-keypad/ ...
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2answers
330 views

Calculator with phone keypad question [closed]

I am not an electronic person and found this site in a my quest for the perfect calculator. I use both a phone and calculator for calculations and find the back and forth to cause me to make errors ...
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2answers
666 views

Arduino 3 digit LCD calculator

We would like to build a calculator using Arduino which uses 3 digit LCD and a keypad similar to digital phones. (# for plus , * for minus) Which components and way is good enough to not to run out of ...
3
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3answers
2k views

Which schematic is better for keypad connection to an MCU?

I have this three keypad connection sketches, all of which i've seen in various application, and some i've also used, but i want to know if there is any advantage of one over the other. The keypad ...
2
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1answer
409 views

Information on this keypad

I receieved this 4x4 keypad in an electronics kit, but don't know what the pins (it has 2x5 pins), are, and can't seem to find a data sheet for it. Any info or help is appreciated!
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2answers
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Interfacing a keypad with a microcontroller

I am using a PIC16F877A, running at 20 MHz. I have two paralleled, 3 columns, 4 rows keypad. My setup is as follows: KR1 to KR4 are rows, KC1 to KC3 are columns, and they all go to the ...