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Questions tagged [keyboard]

A Keyboard is an 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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Replacing USB-C socket on a keyboard

I decided to fix some of my stuff that has broken USB-C ports. (why are they so fragile!) I've removed the old sockets and cleaned the pads, but when the old sockets were damaged (by simply inserting ...
Haverford West's user avatar
0 votes
1 answer
69 views

USB cables being affected by manufacturing equipment [closed]

I am an IT guy, who enjoys learning about some of the electrical engineering side of things, but I don't have a good grasp of the jargon. We have a client with about 40 different smaller production ...
Matt Tisdel's user avatar
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1 answer
32 views

How to find the matrix layout of an old EEPC keyboard

The title asks my question; how can I find the matrix layout of an old EEPC keyboard. I found an instructables about making a USB keyboard controller but it uses a Teensy microcontroller, and I think ...
ImTheBeemoPlush's user avatar
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0 answers
40 views

How to short time delay controller?

I have an old keyboard which I use for decorative purpose. It has RGB lights which turns on for few seconds when a key is pressed. I want to keep them on at all times. How to achieve this? Can I ...
Saransh Bairagi's user avatar
1 vote
0 answers
22 views

RKJXT1F42001 Logic diagram

I'm looking into integrating an RKJXT1F42001 4-directional stick switch with encoder and center push function into a keyboard I am designing, but a little confused about the diagram. I want to make ...
printsmith3d's user avatar
1 vote
0 answers
10 views

Multiple Qi transmitter/receiver pairs powering one device

*disclaimer: I'm just a tinkerer and this is more of a hypothetical thought exercise than anything. I'm planning on adding a usb-c Qi receiver to my keyboard, and I was wondering if it would be ...
Geoffrey Sauer's user avatar
2 votes
2 answers
82 views

Home made USB 2.0 device switcher (for mouse/keyboard only)

I did buy some off the shelf ones, but they seem to fail after a few months and or screwing up the USB ports. I opened the switch box up and noticed that the two power lines were always connected to ...
Newb Coder's user avatar
1 vote
0 answers
45 views

How to test Keychron K3 Pro PCB LEDs

After plugging Keychron K3 Pro keyboard to USB port on Tesmart KVM switch (used not original power adapter maybe it worked not stable), after 10 min of working keyboard and mouse unplugged and light ...
Lion's user avatar
  • 11
2 votes
1 answer
147 views

Why are these diodes on the row inputs of this matrix keyboard with column pull-ups?

The following is the keypad circuit of a NEC TK-85 8085 trainer board. Port C-upper of the 8255 programmable peripheral interface is set to output, and you bring low the row you want to scan, leaving ...
cjs's user avatar
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0 answers
267 views

Can I connect my own hardware to a universal 2.4GHz RF wireless receiver?

I built a USB keyboard for PC with a microcontroller, and it works great. The next challenge is to do it wirelessly. I have seen that sell universal 2.4GHz RF to USB wireless receivers, similar to ...
Fabián Romo's user avatar
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1 answer
158 views

Column of keyboard keys not working

So every key that is on this trace is not working. Is C25 the culprit? It is a mechanical keyboard and there is continuity between all of the keys on the trace, and they all go to this jumbled mess of ...
user318422's user avatar
-2 votes
2 answers
81 views

Tricking CPU's with specially crafted RF signals

Is it possible that I can modulate and craft a RF signal that, once demodulated by a WiFi card and turned back into electrical signals or binary data, can trick the CPU into thinking it's a command ...
19216811's user avatar
0 votes
1 answer
65 views

Connected my keyboard to Apple 67W USB-C Power Adapter: Voltage Concerns [closed]

I recently had an experience with my keyboard (HHKB Professional Hybrid Type S) that I wanted to get some additional insights on. Specifically, I accidentally connected my keyboard to a 67W Apple USB-...
KF Hed's user avatar
  • 13
0 votes
2 answers
71 views

Wireless Keyboard RGB backlight design

I am designing a split wireless keyboard with a 3.7V 2000mAh LiPo battery and using the BQ24075 for power management. I'm contemplating the use 32 of the SK6803 Mini-E for backlighting. Is this ...
ElectronicGlitch's user avatar
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0 answers
46 views

How can I replace the keyboard lights with 12 volt lights?

I had an idea in mind: connecting the three keyboard lights to three external lights that operate on a 12-volt current by using an NPN transistor circuit. However, when I tried to implement the idea, ...
Saad Ess's user avatar
0 votes
1 answer
47 views

What is it needed to repair the pressure pads of an electric piano keyboard? [closed]

I don’t know if this is the right place to ask, but this is important to me, so i hope you understand. I have an electric piano keyboard (Korg Kross I). It is supposed to detect automatically the ...
Simón Flavio Ibañez's user avatar
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1 answer
68 views

Multiplexed keyboard based on MOSFET for AVR gives sometimes wrong reading

I made simple example for multiplexed keyboard 2x2 on AVR. Like schematic below: And Source code: ...
Leszek Mazur's user avatar
0 votes
1 answer
185 views

Schematic design review of a custom macropad with an ATmega32U4

This is the first time I've made a "more complex" PCB. Before I buy all the parts it would be nice if someone could check my design. ATmega32U4: Datasheet
Finn's user avatar
  • 13
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0 answers
348 views

Scanning a keyboard matrix

I recently watched a video on YouTube by Branch Education. In this video, they describe two methods for scanning the matrix: Sequentially apply a voltage across each column so that at any instant ...
vector X's user avatar
0 votes
0 answers
72 views

The receiver sends correct but too much information to the keyboard with STM32 nRF24

I have a problem with keyboard hid. I did remote control with STM32 transceiver nRF24. My problems that receiver true receiving incoming data but too much text. Problems that: ...
Sk16's user avatar
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0 votes
0 answers
80 views

Identifying Cherry MX-5000 Keyboard controller chip ZC86963P

The Cherry MX 5000 ErgoPlus keyboard (model G80-5000 HAAUS) has been out of production since the 1990s. I'm trying to identify its controller chip. If I can locate a data sheet, I hope to dump the ...
ʇsәɹoɈ's user avatar
-1 votes
1 answer
384 views

Can I connect ESP32 GPIO to USB D+ and D- through a CH340 converter?

I want to see what a wired keyboard (and later a mouse) outputs to an ESP32, so I am thinking of connecting a wired keyboard's USB to a CH340 (USB to UART) converter and then connect it to GPIOs of an ...
GnomeMage's user avatar
0 votes
1 answer
281 views

How does the Dumang DK6 keyboard work? [closed]

The Dumang DK6 keyboard is a modular mechanical keyboard, where each key is mounted into an independent saddle with its own microcontroller, and each saddle can be independently positioned anywhere on ...
Verax's user avatar
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0 answers
77 views

How do I connect to the strange black contacts on a PC keyboard's PCB?

I want to build a little box with switches, so that I can flip a switch and it will hold down a keyboard key on my PC. My idea is to take the little PCB from an existing keyboard (a Microsoft Wired ...
Greenaum's user avatar
  • 310
1 vote
2 answers
100 views

Identifying a keyboard component

Recently I found an old ACER 6312-TA keyboard that I want to repair. Everything seems to work fine except for this component that I can't identify: I bet the reason this keyboard is not working has ...
Arroz con Tomate's user avatar
1 vote
1 answer
304 views

BLE HID Keyboard Device for iOS

I'm using a Dialog SmartBond DA14531 as a BLE HID Keyboard device. It works on Windows but not on iOS. Although it pairs successfully, the HID key events do nothing. Does anyone have any experience ...
Charlie Skilbeck's user avatar
0 votes
1 answer
164 views

What signals does the flat cable send in laptops?

Can the flat cable through which the internal keyboard in the laptop is connected transmit PS/2 or USB signals? Or does it send some other signals like serial or parallel, which are then converted on ...
another.unix.hacker's user avatar
0 votes
0 answers
101 views

Best approach to driving custom RGB mechanical keyboard LEDs

I am in the middle of designing a custom mechanical keyboard and have just finished the PCB schematic, but before I spend a few hours placing and routing components, I thought I might ask y'all a few ...
mistasef's user avatar
0 votes
1 answer
84 views

Keyboard inside glove [closed]

I have an idea on keyboard inside a glove. You would wear a glove which would have little switches inside every finger. When tapping with the finger it would send the index of the finger to the ...
joojn's user avatar
  • 13
0 votes
2 answers
866 views

PCB design review (ATmega32U4 keyboard PCB)

I've been working on an ATmega32U4-based PCB for a custom keyboard for a while now. I made a few prototypes with similar designs, but they all seemed to have issues with the microcontrollers dying ...
Andrew Chao's user avatar
0 votes
1 answer
81 views

Joining two rigid PCBs in a non-flat configuration [closed]

I would like to design a very minimal split keyboard like the GergoPlex or Ferris Sweep, but my wrists get sore easily with extended pronation and ulnar deviation. As such, the design I have in mind ...
ConlangBabble's user avatar
1 vote
2 answers
3k views

Keyboard diode design

I have a question about keyboard diode placement. (Pardon my ignorance if this is simple question I have no electrical engineering background.) The diagram below shows how a keyboard schematic is laid ...
Gabriel's user avatar
  • 111
0 votes
1 answer
394 views

Mysterium Keyboard ATmega32a malfunctioning. "USB device not recognized."

I tried sourcing all the parts for this keyboard. I soldered everything up and when I plug in the keyboard I immediately get an error message "USB device not recognized": My first though ...
Peoncup's user avatar
0 votes
0 answers
38 views

Will a Casio keyboard work with a lower current adapter? [duplicate]

My electronic keyboard uses a 12V 2 ampere adapter. Will it work with a 1 ampere adapter?
Dj Mixer's user avatar
3 votes
2 answers
1k views

STM32 USB HID Keyboard skipping key presses

I have an STM32F3DISCOVERY evaluation board which has an stm32f3 mcu on it. I am trying to use the board to emulate a USB keyboard. I used the STM32CubeIDE to enable USB communication, configure the ...
Nick's user avatar
  • 199
0 votes
2 answers
192 views

Keyboard Repair: Both Shift Keys Dead [closed]

I have an old notebook working perfectly fine. The only issue is that both shift keys are completely dead: keyboard top view keyboard bottom view ...
Jeron Baffom's user avatar
-1 votes
1 answer
365 views

Can a PS/2 keyboard be converted to USB hot swap (plug)? [closed]

I have an old keyboard made in 1998, and I want to use it, but my computer does not have a PS/2 port. I bought an adapter to convert the PS/2 of the keyboard to USB. I know PS/2 cannot hot swap. But ...
Shane's user avatar
  • 101
3 votes
1 answer
147 views

Replacing a keypad on DYMO LetraTag

I'm rebuilding my label printer to become an Internet service using an ESP8266. It's a fun project, never mind the usefulness. The keypad will be removed and instead my MCU emulates keypresses. The ...
mikabytes's user avatar
  • 181
0 votes
1 answer
107 views

Could anybody help identify this connector?

Would any of you recognize the following connector ? It's on a old Dell laptop motherboard (M3800). It's to connect the led circuit from the lit keyboard. The flat brown cable from the lit keyboard ...
Stéphane Lieben's user avatar
1 vote
1 answer
208 views

Purpose of PNP transistors connected base to base in 1V/Octave synthesizer keyboard circuit

The circuit below (found here) is designed to be used in a 1V/octave keyboard used to control a synthesizer. When the potentiometer is adjusted properly, pressing the buttons produces output voltages ...
dylaneck's user avatar
2 votes
1 answer
174 views

What can this pin on my keyboard connector be?

I'm trying to place a USB-C connector on my keyboard so I can use a removable cable with it. It's a Ozone Strike Pro with audio and USB pass through. I managed to map 10 of the pins with a multimeter ...
Josy Sclei's user avatar
1 vote
1 answer
840 views

STM32 matrix keyboard scanning gets random keypresses

I am trying to implement a keyboard with STM32 controller (since I managed to burn all my ATMegas and STM32 was all I have). It uses two matrices of keys (it was supposed to be a split keyboard, but ...
shybovycha's user avatar
1 vote
0 answers
206 views

Teensy++ 2.0 doesn't jump into bootloader using software

I have a Teensy++ 2.0 with 90USB1286 CPU running QMK. I'm trying to make it jump into the bootloader using the QMK software. I tried two approaches: Mapping a RESET...
Jakub Jindra's user avatar
-2 votes
1 answer
74 views

What is the difference between making a resistor based keypad and not using a resistor on arduino? [closed]

I've seen videos on youtube about how to emulate a keypad on arduino. Some of them includes a resistor while others do not. What are the difference between them and are there advantages in doing one ...
Gale Design's user avatar
3 votes
1 answer
173 views

How can this 74 series Inverter circuit be analyzed?

I'm trying to analyze the keymech scanning / sampling circuit in the WASP synthesizer So far I understand that the keymech is sampled one key at a time by the 74 series logic driven by the dual ...
andowt's user avatar
  • 1,008
0 votes
0 answers
42 views

How to communicate when a packet starts and ends (send two bytes in one packet)

I am aware that there are some libraries around this topic and that it would be easy to make this type of keyboard if I'll use different kind of arduino. I am doing it for learning purposes and couldn'...
PastaLover's user avatar
2 votes
1 answer
1k views

Unusual USB keyboard wiring - repair needed

New to anything electrical, and I'm trying to make an urgent fix for my wife's keyboard. She has a disability, so needs a specific keyboard to work, and the USB plug on the keyboard has been damaged ...
craigg123's user avatar
0 votes
1 answer
1k views

Keyboard column not responding

Have a keyboard with hotswap sockets that was previously working... suddenly one column no longer works. Specifically the column consisting of 6yhn does not work anymore. Here is a link to the ...
hwrd's user avatar
  • 117
1 vote
3 answers
269 views

Decoding and connetting a keyboard PCB [closed]

I want to build a laptop from a raspberry-pi and an old "toy laptop" (and new components), the spare toy laptop I have is a Oregon Scientific Batman BL31T. I would like to use its case and ...
Fral's user avatar
  • 13
0 votes
0 answers
71 views

Not detecting closed circuit in Goldtouch keyboard key presses

Context While converting the Goldtouch Go!2 Mobile keyboard from Bluetooth to micro USB, I'm experiencing some difficulties in registering the keystroke signals coming out of the FPC connector. Setup ...
a.t.'s user avatar
  • 103

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