--- In l..., aki_kaif@... wrote:
>
> can anyone help me to get started with interfacing a qwerty keyboard with lpc2129..the development board being used is the lpc2129 kit by NSK.please provide me with some tutorials or related information on this..or some sample codes...and i am using KEIL UVISION 3.
>

You might find it easier to complete your project on a different platform. The mbed (www.mbed.org) has libraries for interfacing a number of things including RC servos and a PC keyboard.

The mbed doesn't not require the installation of any development tools.

Richard

An Engineer's Guide to the LPC2100 Series

--- In l..., aki_kaif@... wrote:
>
> thank you...
>
> can anyone help me to get started with interfacing a qwerty keyboard with lpc2129..the development board being used is the lpc2129 kit by NSK.please provide me with some tutorials or related information on this..or some sample codes...and i am using KEIL UVISION 3.
> >
> >
>

As you can probably guess, it may turn out that none of us has actually implemented a PC-AT keyboard on a LPC2129 and can simply hand you the electrical design and code.

Again, try Google! If you search long enough with enough variations, you might run across:

http://blueboard-lpc214x.googlecode.com/files/KeilSampleProjects.zip

To use this code, you will have to review how the BlueBoard is wired and do something similar on your board.

http://code.google.com/p/blueboard-lpc214x/
http://blueboard-lpc214x.googlecode.com/files/BlueBoard_schematics_V1R1.pdf

I did note that the Blueboard can be fitted with an LPC2129 so I suspect that there is a lot of similarity between the LPC2129 and LPC2148 in terms of pinout. In any event, you should review the LPC2148 User Manual and see what P0.16 and P1.16 are all about. Perhaps they serve the same function in the LPC2129.

Richard

Hi

On Sun, Feb 6, 2011 at 2:24 AM, wrote:

> thank you...
>
> can anyone help me to get started with interfacing a qwerty keyboard with
> lpc2129..the development board being used is the lpc2129 kit by NSK.please
> provide me with some tutorials or related information on this..or some
> sample codes...and i am using KEIL UVISION 3.
>

For the connection, there is a good tutorial at:
http://www.computer-engineering.org/ps2protocol/

This should get you up and running with a PS/2 keyboard.

Cheers
--
Olivier Gautherot
o...@gautherot.net

--- In l..., aki_kaif@... wrote:
>
> can anyone help me to get started with interfacing a qwerty keyboard with lpc2129..the development board being used is the lpc2129 kit by NSK.please provide me with some tutorials or related information on this..or some sample codes...and i am using KEIL UVISION 3.
>

Cart before horse.

First, you have to connect the keyboard to the uC. Until the hardware interface, (and possibly protocols if keyboard is 'intelligent'). is defined, there can be no code.

PC-style keyboard, membrane switch-array or what?

Rgds,
Martin

thank you...

can anyone help me to get started with interfacing a qwerty keyboard with lpc2129..the development board being used is the lpc2129 kit by NSK.please provide me with some tutorials or related information on this..or some sample codes...and i am using KEIL UVISION 3.
>

--- In l..., aki_kaif@... wrote:
>
> can anyone help me to get started with interfacing a qwerty keyboard with lpc2129..the development board being used is the lpc2129 kit by NSK.please provide me with some tutorials or related information on this..or some sample codes...and i am using KEIL UVISION 3.
>
You really should search on Google - there's a lot of stuff out there.

Try http://www.beyondlogic.org/keyboard/keybrd.htm to understand what you are going to send/receive. There is code provided so you can see the overall flow even though it is for a different processor.

But there's a problem with the code in that it depends on polling the keyboard and waiting for transitions. You will almost certainly want to use interrupts.

The interface is bidirectional so you will have to set the output pin state to logic 0 and control the signals by changing the pin direction from input (bus is '1') to output (bus is '0'). This allows the bus signals to be controlled from either end and float at 5V.

Look on page 5 here: http://www.inexglobal.com/downloads/jx-2148_info.pdf for the electrical interface. It is based on the idea that the keyboard wants 5V, the uC is 3.3V and assumes that the pins will be 'open drain' as I detailed above.

You want to select pins that are 5V tolerant and that can interrupt on change.

Richard

can anyone help me to get started with interfacing a qwerty keyboard with lpc2129..the development board being used is the lpc2129 kit by NSK.please provide me with some tutorials or related information on this..or some sample codes...and i am using KEIL UVISION 3.