Based on SCM stepping motor control system design

2.2 the keyboard/LED module
To realize the man-machine dialogue, this system design expanded the 3 x4 keyboard and 4 piece button matrix for 8 LED digital tube, manual operation this control system directly. After power system, through the keyboard input the step motor rev. Stop, the step speed and steering, LED by the dynamic display of the step motor speed and steering. The keyboard input and output of the tube by 8279 LED to control, reduce the burden of single chip microcomputer. 8279 the programming work in the keyboard scan input methods, read, have a keyboard to dither function, avoid triggered by mistake. Figure 3 for the keyboard LED module design structure diagram.
2.3 drivers/amplifier module
http://www.siliconray.com/atmega64-l-a-atmega128-l-a-atmega1281-atmega2561-core-board.html
The control system adopts stepping motor control with pulses of distributors (also called logic converter) PMM8713, this device is CMOS integrated circuits, the phase output driver ability (power source current or inhaled) to 20 mA, apply to control three-phase or four phase step motor, can choose the following six stimulation: the three-phase stepping electricity into: 1 phase, 2 phase 1-2 phase; Four phase step electricity into: 1 phase, 2 phase 1-2 phase. Input mode can choose single clock (plus direction signal) and double clock (are turning or reverse the clock) two ways, has the positive &negative control, initialization reset, monitoring, the origin of the stimulation monitoring and input pulse monitor etc. Function. PMM8713 device by the clock choose the incentive mode control, stimulation judgment and reversible counter parts of ring, etc, all input ? within