AT89C52，四个按键控小四轮驱动小车。前进、后退，左转（右边两轮前进，左边两轮后退），右转（右边两轮后退，左边两轮前进）-AT89C52, four buttons control the small four-wheel drive car. Forward, backward, turn left (on the right two forward, two back left), turn right (on the right two backward, left two forwa