[DeTomaso] Optical turn signal control

[David Fisher]

It looks like you are having a lot of fun.   I'll date myself, but I recall
making a x y milling controller off a Z80 eval board.   Pretty satisfying
to get all the things to work together.

Keep all the creativity coming... love to see it.

David



On Sat, Jan 26, 2013 at 8:13 AM, <gow2 at rc-tech.net> wrote:

> > Cool stuff... do tell more...
> >
> > David
> >
> >
>
>
>
> The control for the turn signal encoder is called the Arduino. The Arduino
> is what I call "a micro controller for dummies". These type of platforms
> are becoming very popular. Arduino is one of the most popular platforms
> with an enormous wealth of information.
>
> I call it a micro controller for dummies because yu don't have to
> understand much about the micro controller. Configuring and programing is
> basic. If you have done ANY basic level introductory program you can
> follow the examples which are plentiful through Google and books. It is
> just about getting the syntax right.
>
> The Arduino has a compiler (free download). The Arduino plugs into a USB
> on the computer. If you want to control say a servo, in a Micro Controller
> you may have to create a signal at a specific pulse width to operate the
> servo. In the Arduino, you make a note in the beginning to add a servo,
> name an item a servo then tell the item to move to a position. It's that
> simple. The rest is how you nest your program to do what you want.
>
> There is an explosion of these sort of boards right now. I would say the
> Arduino is one of the most popular for this sort of application. Radio
> Shack is even carrying these now; along with the LCD I use, and intro
> boook, etc.
>
> Someone directed me to a new board this week which...is not really what I
> need here, but is unbelievable. It is basically a computer which runs
> linux in the same configuration with massive inputs and outputs. It is
> called the Raspberry and is ....$35. !!!!!
>
> http://www.alliedelec.com/lp/120626raso/
>
> Back to the Arduino. I start with the "Uno" which is a prototyping board:
>
> http://arduino.cc/en/Main/arduinoBoardUno
>
> It has 14 digital input/output pins and 6 analog input output pins. I work
> out the logistics with the prototyping board then move to a more solid
> solution.
>
> I have circuit boards made for the NANO which is pretty much the same
> thing except it is designed to be soldered on a board:
>
>
> http://arduino.cc/en/Main/arduinoBoardNano
>
> The circuit boards I have made are designed to hook up the things I need
> such as a voltage converter to take the voltage from 12v to 5,  sockets
> for thermocouple chips, encoder counters, pull up/down resisters, mods
> etc. It is a flexible circuit in which I am on my 3rd rendition.
>
> The encoder itself is not hard but the timing can be tricky. The encoder
> has 2 LED emitters/detectors. They are staggered 1/2 wave. The logic is to
> read the separate waves. If both are high and one goes low, you know which
> direction it is moving. Each move provides a count.
>
> The tricky spot is timing. If you are doing things in the program when the
> count comes across, you will miss it. A separate chip is used to take care
> of the logic. It is a very simple chip which works well for this
> application. It tags the Arduino on 2 pins. One pin is an interrupt. It
> gives direction and count +/- 1. The interrupt is the key because at every
> count it interrupts the program and updates the count so nothing is
> missed. Works very well for this application.
>
> The arduino will also manage 8 servos on the heaterbox in a constant loop.
> If an input condition has changed it will turn on the servo, move it, and
> turn it off.
>
> There is a whole group of conditions going on in the turn signal process.
> It will control each of the 4 turn signals and flashers via a power
> mosfet. It has a few things to consider; position of the wheel, are the
> flashers and turn signals on at the same time, are the lights on (the
> front marker is both marker and turn signal), manual cancel, etc.
>
> I can do creative things like make the front marker both a turn signal and
> a marker. If flashers and turn signals are on, I will flash 2x, turn
> signal 2x, flash 2x, etc. If I leave the turn signal on for 5 min, turn
> them off. Things like that.
>
> he left is the prototype. The right is the actual column. You are seeing
> the bottom of the column:
>
> http://www.rc-tech.net/cars2/panttransam/turn/turn3.jpg
>
> I have been working through the learning curve on the prototype. This
> involves making a lot of mistakes, figuring out what I have done and
> getting it right. A soldered board is so much better when done right the
> first time. As I get parts nailed down, I hope to begin putting it
> together in the car Sunday with some finish wiring. So much still to do.
>
> The mile stone for me was getting the encoder to read reliably without
> error which I have done. That above all was the hardest part. The rest is
> just logistics.
>
>
> Gary
>
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> > On Fri, Jan 11, 2013 at 2:51 PM, <gow2 at rc-tech.net> wrote:
> >
> >> Here are some parts being used to build the encoder based turn signal:
> >>
> >> http://www.rc-tech.net/cars2/panttransam/turn/turn.jpg
> >>
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