OSCC has the goal to provide a cheap option to hobby-grade slot car controllers.
The heart of OSCC is a ATTiny84 microcontroller running Arduino. The Arduino reads analog input from the throttle hall effect sensor and the settings potentiometers. The inputs are converted into two PWM outputs. One PWM drives the P-Channel MOSFET that enables the car to move forward. The other PWM shorts the motor circuit to enable breaking.
Short CALIBRATION_PIN and GND to calibrate the trigger. Move the trigger
from full brake to full throttle a few times. Remove the short to GND. The
controller should now use the new calibration. The calibration is saved in EEPROM
and will persist between restarts.
Three analog values can be fed into the controller. This is preferably done using three potentiometers.
ATTACK_ADJ_PIN sets the "Attack" of the car. This is the initial value for when
the trigger is gently squeezed.
BRAKE_ADJ_PIN sets the strength of the brake, when the trigger is fully released.
TRACTION_ADJ_PIN controls how fast the throttle can increase.
The circuit is built for a track running at 10-12 Volts with the shared braid beeing the negative(ground). The controller should be hooked up to:
- Red: Track ground (minus from power supply and left braid).
- Black: Right braid.
- Yellow or White: Track +10-12 Volts.
The complete circuit:
