The following stepper pulse generator based on AD654 is not only a very important tool but also can be used to drive stepper in standalone mode.This stepper pulse generator project has multiple features which are a must for stepper controller. It has on board frequency generator with wide span of frequency with the generates square wave pulses in frequency range 0-50Khz, Slide switch for direction control and jumper for enable or disables the stepper controller. Here, AD654 is a monolithic Voltage to frequency converter consisting of an input amplifier, a precision oscillator system, and a high current output stage. It generate the pulse for stepper controller, output frequency 0-50Khz, higher frequency output is possible by changing CT capacitor value connected between pin 6 and 7. As well as the board,there is an LM317 regulator and have an input supply of 7-36V DC. A on board LED for power indication, PR2 trimmer potentiometer to set the frequency. PR1 is to fine tune the frequency, slide switch SW1 to change the direction of stepper motor, J1 Jumper to enable or disable the stepper controller. All outputs are TTL level. Change the R3 to 0E if stepper controller has opto-coupler input. LM317AEMP Datasheet