I never had a reason to hack anything.
But I do now. I have the tools and the know how to
change the way very basic items work.
The question is... How do I want to change them?

The first thoughts are what capabilities does the hardware
have. In this case, the car can move forward, reverse, left 45 degrees,
right 45 degrees and straight.

How can I draw anything with those limitations?

And then the question becomes how to hi jack the controls.
It would be nice not to have to build a lot of new circuits to control
what this board already controls. But to take control of it I'd have to
understand it. And while that's not such a far fetched notion... it's
still a very difficult and time consuming puzzle to solve.

Reverse engineering things is hard. Writing the schematic for a board
requires some spacial reasoning as when I flip the board I have to remember
that the pieces are all reversed and with so many connections so close together
it can be difficult to pin point what connects to what.

I find myself flipping the board over and over again and still
not able to plot the circuit out.

I thought I had a chance with it because it was such a simple
board. One layer, only one unknown chip. All the rest of the
components are recognizable. My guess is that their using
a 4 transistor bridge to control the directions of the motor and
that the rx chip in the center of the board pulls in the frequency
and assigns digital signals to it before sending it off to t
he motor control circuitry.

One note on technique. If your spacial reasoning skills are lacking it may help
to use the tools at hand to get a better idea.

Here I've reversed and overlayed the back of the board onto the top and made it
a bit more transparent. I've also lined up the chip holes a bit. If you take
your pictures carefully and make marks directly on the images... you may have
a better chance at solving the problem. I think it characterizes my thinking
in other areas of my life nicely.

That is if you don't have the skills to do a task... find a way to build them for
yourself. As long as the end result is the same there's no harm in it.

I think how I rig the controls depend on how much time
I want to spend. I may as well rig my own motor control circuitry
and just ignore the board if I want to rush it.
But then it dawned on me....

I could hack the controller instead
of mounting the chip on the car.
Then I wouldn't have to worry about crashing.

the only problem with that is I wouldn't be able to mount
accelerometers on the car for position and speed information.
I suppose I could try both. Hack the controller first and then
mount a chip on the car. ... Eh.
Something..

But the whole point is to stick a drawing mechanism on
the thing and convert curves on the computer screen
to chalk on the road. In other words, I'm making a fancy
drawing bot. I had a smaller rig with a slower mobile
robot. But I want to draw fast and over a wide range.
Which is the other reason I'm not sure the remote is
the best plan.

Course I could always stick the remote on top of the car
as well. That would be a simpler hack. And I could make
it detachable.

Oh well, that's the thinking anyway. I haven't become to
figure how I'd convert the curve information of a drawing into
the directions for the vehicle.

Oh yeah... and there were these spiders on my window....

Spiders on my window