A Keyboard is a input device typically made of a large array of switches. The interface could be the raw matrix, or an industry standard protocol like PS/2 or USB.

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How to find connections on board? - DIY Keyboard from Old Laptop

I have a project that I have hit a wall on. I need your guidance! I need to find the spots on the board for the 4 USB connections. The attached photo is of the board. There are 4 connections I ...
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1answer
41 views

Designing a Bluetooth Keypad/Gamepad with MCU/SOC. (32 GPIO, 14/chord)

I have a Blackberry Keypad, and a custom Gamepad. I am trying to make them into bluetooth HID(s). They will be part of a single physical unit/board. I need help to get those inputs into a bluetooth ...
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2answers
252 views

LED circuit is draining AA batteries REALLY fast

My question is long, rambling and weirdly specific. I hope I'm not violating like 50 stackexchange rules, but I'm completely lost. Long-time lurker, first time asker and pretty new to circuits in ...
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1answer
57 views

Is it possible to convert the battery power supply in old devices?

I have an old Yamaha keyboard/synthesizer lying around that I'd like to start using with battery power. However, it takes 6xC (1.5v) batteries to power the thing up. My question is, is it possible to ...
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1answer
462 views

How can I send keyboard input to USB port or Serial Port?

Now, I am using Windows 8 and have made Arduino buttons to operate as an keyboard's 4 arrow keys(up,down, right and left). From this moment, I am going to send this keyboard input event out to the USB ...
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1answer
174 views

How to design a keyboard circuit that can use a passive USB-to-PS/2 adapter?

I'm designing a small device that will act as a USB HID keyboard, but it must also work with PS/2 hosts. I would really want to be able to use it with one of these nifty passive USB-to-PS/2 adapters ...
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2answers
44 views

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

(Mini)USB keyboard has D- default high

I have a keyboard from an old tablet case with a mini-USB connector that I want to read out using a PIC32 microcontroller. When I apply 5V to the keyboard (completely standalone, no other circuitry ...
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1answer
238 views

USB Keyboard with 18F2550

I'm trying to build my own mechanical keyboard. Everyone uses Teensy as for as i can see. I wanna use PIC18F2550 instead. I'm using CCS C btw. The problem is, i can't send more than 5 bits at all. ...
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0answers
51 views

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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0answers
93 views

Arudino Simulating Button Presses on Keyboard

I am currently working on a project that involves automating an old Automark Indenting Machine. I want to be able to use an arudino to read a csv and then simulate pressing the keys of the keyboard ...
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1answer
107 views

PS2 or USB keyboard for custom CPU

I have made a CPU on an FPGA board. It works great but I cannot proceed to make a computer with it until I have an input. What use is a computer if it can talk to you, but you cannot talk to it? It ...
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1answer
571 views

Soldering on keyboard controller circuit board

For fun, I took a USB keyboard apart as I'd like to use the keyboard circuit board without the actual physical keyboard. I am in need of soldering advice however. Opening up the keyboard I see this: ...
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1answer
365 views

38 kHz signal arduino demodulation

I need to demodulate signal with frequency 38 kHz coming from remote controller without IR receiver. I need to demodulate it and as a result get information from it. Is there any examples of similar ...
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1answer
248 views

Electric Typewriter Keyboard help

I'm trying to interface my Arduino Uno with a typewriter (smith-corona sl 460) I picked up in a garage sale a year ago. My final goal is to make it so I can type in something on the serial monitor on ...
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1answer
136 views

How does this inductive musical-keyboard function?

I've been looking to interface with a keyboard that I've removed from a non-functional system, specifically an Ensoniq EPS-16. As luck would have it, I managed to find schematics for the controller ...
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1answer
593 views

Is it possible for a Teensy 3.1 microcontroller to receive USB keyboard input?

As I've read, it is possible to have the teensy act as a keyboard for a computer. I would like to know if the opposite is possible - can I collect keystrokes through the USB port on the teensy. If ...
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2answers
2k views

Recreating a missing wireless keyboard dongle with NRF24L01

I have found an old Logitech Wireless Keyboard (specifically, the MK250 model), which was originally sold with a separated "standard" 2.4Ghz receiver dongle (Not 'Unifying', as written here). I assume ...
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2answers
201 views

Help identifying FFC Apple rMPB keyboard connector

I'm working on hacking a Retina MacBookPro (2013) keyboard for use with Arduino. The keyboard has a 30pin FFC (or is it FPC?) connector interface. I'm looking for any kind of connector that would ...
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1answer
912 views

What capacity LiPO battery is equivalent to 5 AA batteries?

I have a Casio MA-120 keyboard (musical). Which requires 5 AA batteries. On back of the keyboard there are power source instructions which says: ...
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1answer
1k views

Bluetooth keyboard?

Can the Bluetooth board "XS3868" be used for in a Bluetooth keyboard for a computer? Without using an Arduino
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1answer
748 views

keyboard and mouse interface

How do I interface a microcontroller with PC USB so that I can imitate the keystrokes and movement of keyboard and mouse. I've heard of software fixes, but is there any IC which can mimic the ...
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3answers
237 views

Securing a pcb to be used in a keyboard to its case

I'm looking for a way to secure a pcb I will be making for a cherry mx (homemade) keyboard to a case which I'll also be making. Obviously, I don't want the pcb to move. I could use standoffs/screws, ...
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1answer
309 views

Monitoring USB Keyboard Input with Microcontroller

I am currently working on a project in which I would like to be able intercept a specific key combination from a standard USB HID keyboard with a microcontroller. The purpose is to use the keyboard to ...
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3answers
1k views

How would I use this 12 key keyboard?

I'm trying to make this simple code lock circuit, and I ordered this keyboard for it. However, there isn't any kind of manual for it, and I simply don't understand how it works. Here's a larger ...
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3answers
225 views

Just making sure I won't fry my motherboard?

I'm building this circuit, which converts a toggle switch to a momentary one, which sends a key to a USB keyboard PCB by connecting 2 contacts together: I just wanted to check, how do I know the ...
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1answer
1k views

How to wire/interface a 4x3 membrane keypad

I followed this example to wire my keypad to my STM32F4 Discovery board. However any way I read data on the pins I keep getting same data which leads me to believe I wired something wrong. Here is ...
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1answer
2k views

Is it possible to use msp430 with keyboard + LCD?

I'm trying to do an assignment for my class which requires me to use a keyboard as input through a microcontroller to a LCD screen, nothing fancy , I just need to show that when I press characters on ...
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1answer
232 views

How to create traces that don't touch for a four by four non matrix keyboard grid

Hello. I have a potential design for a keyboard whose pcb I will make myself in eagle. This will use cherry mx browns (http://www.cherrycorp.com/english/switches/key/mx.htm for info. Rather than use ...
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2answers
726 views

Illuminate keyboard using Scroll Lock key

I have a keyboard that I'd like to illuminate when pressing the Scroll Lock key, but I'm not really good when it comes to designing something like that. I'm planning to use a transistor that will ...
2
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2answers
247 views

connect LEDs to USB keyboard – but they turn off after a second

I have a USB keyboard. As I work many times in the darkness, I put some LEDs into the keyboard case. I connected two pairs of yellow standard LEDs serially to the USB power lines (Vcc and ground, pin ...
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2answers
2k views

How to go about making a keyboard with arduino as the controller [closed]

These are questions I have found that are similar to mine: Arduino as full fledged keyboard controller? This is somewhat similar but it sounds like op is trying to connect an existing keyboard How ...
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2answers
795 views

Building a wireless keyboard (preferably with a kit)

This is the project that spawned these earlier questions. I'd like to create my own keyboard. Functionally it's going to be a keyboard, but visually it's going to bear more semblance to a joystick ...
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180 views

Electrical properties of keyboard keys

I'm looking to hack together a keyboard by taking an existing keyboard and connecting it to switches that I'll assemble separately. What I want to know: What should be the electrical properties of ...
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2answers
4k views

How to uniquely identify USB HID class device?

I would like to identify a USB keyboard uniquely(something equivalent to unique mac-id for the Ethernet cards) on a computer. Does the USB HID profile has a support for such identification ? If so ...
3
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1answer
237 views

Tuning an electric organ keyboard

I have an old (1960's) Whippany Dart combo organ. Each set of three keys has a tuning pot that raises and lowers the pitch of those three notes (turning clockwise lowers the pitch, and ...
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4answers
3k views

How to find socket for keyboard connector?

I am looking for a socket which is able to receive the connector of the ThinkPad X41's keyboard. How do I identify the socket so that I can find it on the (German) market? Background: I want to build ...
3
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1answer
2k views

Arduino as full fledged keyboard controller?

I am considering connecting a ThinkPad X4x keyboard to a PC, using a programmable KeyWarrior keyboard controller in between the keyboard's ribbon cable and the USB cable to connect it to the PC. Not ...
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1answer
171 views

How Can I Program a Universal Application Keyboard? [closed]

IMPORTANT NOTE: This is a question from who has no experience and knowledge on this area. So before giving negative rep, please provide constructive suggestion. I want to program a universal ...
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3answers
846 views

How does the ZX80 keyboard avoid ghosting and masking?

I believe that a keyboard matrix needs a diode on each key to avoid ghosting and masking. http://pcbheaven.com/wikipages/How_Key_Matrices_Works/ The ZX80 (and probably ZX81) has only a diode for ...
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1answer
965 views

using the PS2 keyboard library with Arduino Leonardo

I'm having difficulties getting the PJRC PS2 keyboard library working reliably with the Arduino Leonardo. I'm relatively new to using the Arduino, but this library seems to be the recommended way to ...
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1answer
706 views

usb keyboard with many simultaneous key presses

I am looking to make a keyboard that allows for 2 or so keys pressed at the same time by the same finger. ie s and w would both register and a total of 8-10 keys registered at 1 time. the keyboard ...
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2answers
3k views

Creating a keyboard with a microcontroller, do I need an input pin for each key?

I am planning to implement V-USB with an ATMega8 microcontroller. I am interested in implementing an HID device; more specifically, I want to try and make my own simple 26 key keyboard (each ...
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4answers
29k views

How to make an USB keyboard work with Bluetooth instead?

I have an USB keyboard (HHKB) which has some great irreplaceable features(That's why I would not like to buy a Bluetooth keyboard directly) and I love to use it very much. But the only improvement I ...
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384 views

Using a Keyboard in a 556 Stepped Tone Generator

I'm in the process of making a simple stepped tone generator using the 556 timer, but I want to be able to have different resistors to change the pitch of the tone I get out. I think it would be ...
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1answer
131 views

Keyboard and mouse chips to buy [closed]

i need to buy a keyboard and mouse chips(every thing in mouse and keyboard not made of plastic ) and i want to know what`s the prices of each and how to buy it and thnx in advance.
2
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1answer
479 views

How do you make the LEDs come on for a PS/2 keyboard?

I'm making a simple console type thing for the mbed with a PS/2 keyboard and VGA monitor. I have a PS/2 library working and can receive scancodes and such. I want to go above and beyond what it allows ...
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5answers
777 views

Interface 5v digital pulses to keyboard contacts?

I currently have the following bit of kit: Photoplethysmographic sensor for measuring heart rate It outputs a 5v pulse each time your heart pulses. What I need is to do is interface this pulse output ...
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6answers
1k views

Need a device that can take single input and covert to a keyboard key press on USB

Let me explain what I'm doing currently. We have made a finger heart rate monitor, each time your heart pulses a transistor is switched on via its base. The collector and emitter of the transistor ...
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1answer
251 views

Keyboard USB cable reconnnection

I've just tried to repair my keyboard's usb cable as it has been damaged right where it goes into the keyboard. I've cut out the bad part of the cable and reconnected the wires. I've tried it and all ...