Re: TI-H: Keyboard
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Re: TI-H: Keyboard
I would be interested in this product. I'm not in need of advising, except
in getting my hands on the microcontroller. I believe I can get the rest.
Would I be charged for asking you how I can get such a microcontroller?
Owen Anderson
resistor@mac.com
on 8/31/00 12:17 PM, M. Adam Davis at adavis@ubasics.com wrote:
>
> Well, here's the deal. You have two routes to go:
>
> One:
> The TI-89 and 92 have external control ability, ie, you can send keypresses to
> the calc, and it will handle them just as if they were typed from the keypad
> without any programming whatsoever. Spiffy, huh? This requires an external
> keyboard interface involving a microcontroller.
>
> Two:
> The hardware interface for the graphlink port and the AT type keyboard (ps/2)
> are similar, both are open collector outputs/inputs. Therefore it is possible
> to make a cable which hooks the keyboard directly to the graphlink. The issue
> here is that they do not speak the same protocol, and the keyboard does not
> spit
> out ascii characters. You will need to write a program on the calculator
> which
> will directly control the pins for the graphlink, accept input, run it through
> a
> translation table, and then insert it into the key buffer on calc.
>
> I personally would go for the first routine, as I am more comfortable dealing
> with uControllers than I am with programming the calc. I am certian, however,
> that an enterprising DOORS developer could go with number two just as easily
> as
> I woul go with number one.
>
> For information on interfacing to a keyboard (electrical and protocol) see
> http://www.beyondlogic.org/
> For information on interfacing and programming the TI calculator, see
> http://www.ticalc.org/
>
> I do a small amount of consulting. If you want me do do the work for you for
> option one, I would charge $45/hr labor. I have the materials, and would
> estimate about 5 hours from spec to design to test to completion. This would
> include one finished product, embedded into a cable.
>
> One item worth mentioning: Keyboard manufacturers have never needed to worry
> about keeping a low power consumption. Some keyboards suck 250mA or more,
> using
> a complete set of four AA's in under 6 hours (continuous use). You are
> advised
> to explore this and other items before embarking on this project.
>
> -Adam
>
> Nivek wrote:
>>
>> --- Grant Stockly <gussie@stockly.com> wrote:
>>>
>>>> hey, what has happend, is this compleat??? can i get one??? where???
>>>> thanks.
>>>
>>> Nothing has happened. No it isn't complete. You can't get one. No
>>> where.
>>>
>>
>> darn, can anybody give me info on how to write the program and what
>> kind of converting i would need to do, so that i can do it myself. for
>> TI-89 if possible.
>>
>> =====
>> Nivek
>> Nivek_ent@yahoo.com
>> http://come.to/NivekEnterprises
>>
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>
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