[Coco] BIGGEST PROBLEM

[David Ladd]

On Mon, Mar 6, 2017 at 10:09 AM, Allen Huffman <alsplace at pobox.com> wrote:

> > On Mar 6, 2017, at 10:03 AM, camillus gmail <camillus.b.58 at gmail.com>
> wrote:
> >
> > I was wondering, if a single 6809 or 6309 can handle USB protocol. If
> this could be done then a second cpu would be easy to imply in the
> exsisting coco's., and act as a dedicated USB controller ( does not have to
> be a 6809 but like to stay in the era )
> > ...
>
> > I don't know I'm just a thinker...LOL
> > But it would be not the first time someone made a big invention from
> someone else s idea's  ...lol
>
> It's a timing issue, I believe. USB is just a serial stream and a protocol
> on it. The Arduino can handle USB for keyboards with just a few wires from
> it's digital pins to a USB connector, but not the stock Arduino. You have
> to swap out the timing crystal. You can buy a "$5 Arduino kit" where you
> wire up some parts to a breadboard and have an Arduino, including the
> timing crystal, so such a board could be wired for next to nothing and do
> USB keyboards with open source software.
>

​This is a nifty option for sure.  There are some other options out there
to Allen.  The PJRC Teensy 3.2 & 3.5 are 5v tolerant on the digital input
pins.​  The Teensy 3.2 is 72MHz ARM micro controller and the Teensy 3.5 is
also a ARM micro controller, but it is 120MHz.

The Teensy 3.2 on the bottom shows something about a USB Host Mode, but I
haven't messed with that part of the Teensy.

As far as the joystick ideas I just ran across some I2C 12bit DAC's which
can be wired to a VCC of 2.7 to 5.5V.  The boards I can across can be set
to a high address or low address space.  Should be able to use two of them
on the same I2C buss, but my know how on this is nothing.  So someone who
is use to using I2C might have better luck.  So possibly using the DAC's to
send a analog signal into the analog inputs on the CoCo's joystick port
MIGHT be possible, but I am no engineer either.

Another side note in relation to the I2C DAC's besides being able to use
the Arduino's I2C libraries might be possible to use those I2C DAC's on the
Raspberry Pi as well.  Since the Raspberry Pi has a I2C buss.  Hmmmm anyone
tried this yet?



>
> BUT, I believe (from foggy memories of researching this a few years ago),
> the timing was faster than what our 6809 could handle.
>
> You will notice many Pi projects chain an Arduino to them for doing fast
> I/O, since while the ARM chip on the Pi is very fast, the OS layer is not
> realtime. Many projects put an Arduino polling pins for reading I/O
> (joysticks, etc.) and then spit that back to the Pi as a USB Serial stream.
>
>                 -- A
>
>
>
> --
> Coco mailing list
> Coco at maltedmedia.com
> https://pairlist5.pair.net/mailman/listinfo/coco
>
​

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| David Ladd a.k.a. PacoOtaktay a.k.a. Drencor                          |
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