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interface computer numeric keypad to MCU

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poxkix

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Is it possible to interface a computer numeric keypad to a MCU?

Was thinking of using the 16F877a or 18F4620 MCU and using mikroC. Is it possible?
 



I did look into them before posting. But I think the keypad they are talking about is the one that we usually use in DIY projects. The keypad I mean is a COMPUTER NUMERIC KEYPAD, like the one on a keyboard at the right side without the other buttons like the letters and function buttons. Not unless they are interfaced the same with the standard keypad.
 

if you are looking at something like the Belkin Mobile Numeric Keypd
**broken link removed**

which has a USB interface you will require a microcontroller with USB host facility such as the PIC24FJ64GB002
PIC24FJ64GB002
 

yeah, it is definitely possible..not only the keypad but the whole keyboard...
just go through the protocols for the at keyboard the older ones with the ps/2 connector...usb ones are the difficult cases...


**broken link removed**

You may also give a look to this if you feel comfortable with atmega..anyways you may give a look to the keyboard interfacing section over there.
**broken link removed**
 

if you are looking at something like the Belkin Mobile Numeric Keypd
**broken link removed**

which has a USB interface you will require a microcontroller with USB host facility such as the PIC24FJ64GB002
PIC24FJ64GB002

Yeah, that kind of keyboard.
Thanks for the MCU link. Is 877a or 4620 not capable of doing this kind of interfaces?

yeah, it is definitely possible..not only the keypad but the whole keyboard...
just go through the protocols for the at keyboard the older ones with the ps/2 connector...usb ones are the difficult cases...


**broken link removed**

You may also give a look to this if you feel comfortable with atmega..anyways you may give a look to the keyboard interfacing section over there.
**broken link removed**

I had read about the keyboard scan codes and I'll only be needing the numeric ones.
Thanks for the link.
I have already researched a lot and I just can't find a sample that I'm familiar with.
 

Yeah, that kind of keyboard.
Thanks for the MCU link. Is 877a or 4620 not capable of doing this kind of interfaces?
the 16F877a or 18F4620 do not support USB
there are some PIC18s which support USB device, i.e. they can act as a device to a USB host such as PC

However, if you wish to attach a USB keypad to a PIC you need USB host support such as on some PIC24s, dsPIC, PIC32s, etc. see
**broken link removed**
 

Okay. I found an interesting information. MikroC has a library for ps/2 with a sample code. I will test it if it works.

Nowadays, I can't find ps/2 numeric keypads, will it still work if I attach a usb to ps/2 converter? I have one at home
 

if you download the Microchip USB Framework for PIC18, PIC24 & PIC32
**broken link removed**

you will find example code for attaching a USB keyboard to a Microchip Explorer 16 board
on my PC is it in directory
C:\Microchip Solutions v2011-10-18\USB\Host - HID - Keyboard

the example PIC24 code is for a PIC24FJ256GB110. However, it should be fairly easy to adapt it for a lower cost PIC24 such as the PIC24FJ64GB002
PIC24FJ64GB002

which can be used with Microchip's new microstick II
**broken link removed**
 

if you download the Microchip USB Framework for PIC18, PIC24 & PIC32
USB Application Design Center

you will find example code for attaching a USB keyboard to a Microchip Explorer 16 board
on my PC is it in directory
C:\Microchip Solutions v2011-10-18\USB\Host - HID - Keyboard

the example PIC24 code is for a PIC24FJ256GB110. However, it should be fairly easy to adapt it for a lower cost PIC24 such as the PIC24FJ64GB002
PIC24FJ64GB002

which can be used with Microchip's new microstick II
**broken link removed**

Thanks for the tips and information. I'll be going for the ps/2 connection. None of the MCU stated above is available in my area.

I found the pin config of ps/2, in the library the 5v should be pulled up. In wikipedia it said +5 V DC at 275 mA. So I need a resistor value of 18.18181818181818. Could I just pull it up with 10k resistor?
 

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