The keyboard attaches to the LCD which has a little micro-controller to check for keystrokes and manage the screen. So, you send characters over the serial port to write to the LCD, and when you hit a key, the micro-controller detects it and sends it over thej serial port. Works quite well. The particular model I used, supports up to 55 keys (5 rows by 11 columns), but I only used a 16 key keypad (4 rows x 4 columns), and thus, 1 of the row connections and 7 of the column connections were un-used. But, then you just need a straight through cable to the TS7xxx board. In your case, the TS7400 only has TTL level serial ports, so you will need to buy a chip to convert the levels if you did not already do so. There was another thread about a chip you can use to do that.
The great thing about this design is that the display can be a long ways away. With direct connected LCD and keypad, the distance is very limited, you eat up a lot of DIO, and you have ugly ribbon cable connecting everything.
I am going to buy a TS7400 soon and make my own daughter board with level converters for the serial ports, signal conditioning for the DIO and AI, and a zigbee chip. I just need to talk them into programming the FPGA for at least one high speed external counter.
Let us know how it comes out. Don.
On 11/16/06, sipnj <> wrote:
Hi, thanks for the reply. How did you plug these in to the board? Did
you have to use any hardware between them?
Thanks again...
--- In ts-7000%40yahoogroups.com, "Don W. Carr" <> wrote:
>
> Since you will not have enough DIO, you should buy a serial LED
display with
> keypad controller.
>
> I used the Oribital Matrix 4x40 with serial controller and 4x4
keypad. There
> are other sizes.
>
> LK404-55 40 Character x 4 Line Serial Interface LCD $121.00
> MA-KPP4x4 Keypad - 4 x 4 Keys (connects to LCD) $15.00
>
> You should be able to drill a round hole and put a rubber grommet.
>
> Don.
>
> On 11/15/06, sipnj <> wrote:
> >
> > Sorry if I am asking too many questions. I like the 7400 WIFI
BOX but
> > I need to add a speaker, an alphanumeric LED display and a matrix
> > keypad as well as a couple of push buttons and status LEDs.
> >
> > What do I need to get in order to connect these items to the board. I
> > know I will have to do some cuttin and rilling to the box. Would I
> > need a lot of electronics to connect these items?
> >
> > Is there a schematic somewhere I can vie how these could be added? I
> > prefer as much plug in as possible.
> >
> > Any suggestions would be appreciated.
> >
> >
> >
>
>
>
> --
> Dr. Don W. Carr
> J. G. Montenegro 2258
> Guadalajara, Mexico
> +52-333-630-0704
> +52-333-836-4500 ext 2930
>
-- Dr. Don W. Carr J. G. Montenegro 2258 Guadalajara, Mexico +52-333-630-0704 +52-333-836-4500 ext 2930
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