A very cute hack for a 1-wire LCD panel interface, including power!

[kf4hcw]

On 2015-01-02 16:43, WB4JFI wrote:
> There are other solutions available as well.  Several different I2C
> LCD drivers are available, and the number of wires is only doubled to
> four required.  I2C is also a shared bus, so one can argue that you
> aren't actually losing ANY pins or connections on any micro that has
> I2C.  I have some projects that have four different devices sharing
> the one I2C bus on Arduinos, without issues. 

This occurred to me... I2C can be more trouble that it's worth in many
cases... one or more of the devices sharing the bus can take down the
entire channel; and on something very small that doesn't have dedicated
I2C hardware you end up using a lot of byte space to make I2C work.

With a little bit of tweaking, this setup _could_ be augmented quite a
bit... what if the first byte selected a target device, and what if you
add a couple of transistors to improve the available current on the line
-- now you have a one-to-many control network that is super robust for
low bandwidth scenarios -- enough for quite a robot. Update several
motor speeds 10 times per second and still have bytes left over to say a
few words on the original LCD display - all over 2 wires... tweak it
just a little more and you don't even have to get the polarity right on
the receiving end... but I digress.

_M

<device 0-255><data><data><data><data><data><null>

-- 
kf4hcw
Pete McNeil
lifeatwarp9.com/kf4hcw