# Model Cars

Robot developments like the SoccerBot are quite expensive, because we basically use the highest quality parts available (e.g. precision motors with encapsulated encoders, LiIon batteries without memory effect, special purpose mechanics, etc.). However, there may be cases when one does not need high accuracy and would like to construct a simpler and more affordable robot system. For such an application we interfaced the EyeBot to several (remote control) model cars, which can be bought from either hobby or toy shops.

Model car companies:

- Graupner
- Robbe
- Tamiya
- Kyosho

Basically all sorts of model cars can be interfaced to the EyeBot controller. The price difference between model cars is usually due to quality differences in motors, power electronics and steering mechanism. Here, I will distinguish between higher quality model cars and really cheap toy cars.

- (A) Quality Model Cars
  These cars usually have proper servos for steering and a power controller which behaves like a servo and has the same connections. Instead of plugging steering and drive servo into the remote control unit, just plug them into two servo outputs out the EyeBot. That's all, your autonomous vehicle is ready to go.

- (B) Cheap (small) Model Cars
  Small, cheap model cars usually do not have proper servos, but a single electronics box which serves are receiver and motor controller. Still, this is no problem, since the EyeBot controller has two motor drivers already built in (see diagram for details).

  - The driving motor has 2 wires. Just connect them to the pins Motor+ and Motor- of the "Motor A" connector of the EyeBot
  - The steering motor has 5 wires, 2 for the motor and 3 for the position feedback. Connect the two motor wires to Motor+ and Motor- for the EyeBot's "Motor B" connector. Connect the resistor connectors of the feedback to Vcc (5V) and ground on the analog connector and the feedback slider to a free analog in put (e.g. number 2).

### Model Car Settings (version B)

    TPU  0     driving speed
    TPU  1     steering speed
    TPU  2-13  free
    TPU 14     PSD
    TPU 15     audio out
    -------
    DO 0-1     driving motor direction (A)
    DO 2-3     steering motor direction (B)
    DO 4-7     free
    -------
    DI 0-7     free (e.g. bumper)
    ------
    AD 0       microphone
    AD 1       battery level
    AD 2       steering angle
    AD 3-7     free