![Stepper motor interfacing with 8255 pdf](https://kumkoniak.com/71.jpg)
It shifts the word left and outputs it through the same port for each step of rotation of the shaft.
![stepper motor interfacing with 8255 pdf stepper motor interfacing with 8255 pdf](http://fasrwebs837.weebly.com/uploads/1/2/5/0/125023147/252093537.jpg)
The program starts with the word 1100 and outputs it through one of the ports. The PPI chip 8255 on the kit can be used for the purpose of interfacing. From Table it can be found that the starting word 1100 is essentially shifted left one bit in each step of the sequence. The pulsing of these stages can be done with the program given. Similarly there are pairs of transistor circuits to energise the coils A1, A2, and B1 as shown in the table. From this it is clear than when D3 bit is zero, coil B2 is energised.
![stepper motor interfacing with 8255 pdf stepper motor interfacing with 8255 pdf](https://i.ytimg.com/vi/Xj8QoHL2lPE/maxresdefault.jpg)
When T 2 conducts, there is a current through the coil B2. T 2 is ON when T 1 is ON, it is OFF when T 1 is OFF. The PNP transistor T1 is ON when D3 bit is 0 it is OFF when D3 bit is 1.
![stepper motor interfacing with 8255 pdf stepper motor interfacing with 8255 pdf](http://midaseng.com/bin/minihome/upload/1524/data/shop/MDA-8086.jpg)
Transistor circuits are used as driver stages as given in fig. The 12V power supply should be capable of supplying more current. The coils require 1 Amp current for rotation, at 12V. In all these and many other applications stepper motors are used. Such motors can be used to provide precise movements as in robot arms, flooppy drives, print head movement and paper rotation in computer printers, machine tool control etc. Thus the shaft can be given precise angular rotations. Reversing the order in the sequence table causes the shaft to rotate counter clockwise. Each successive line of the table causes one step. Changing the excitation from A1 & A2 to A2 & B1 causes the shaft to rotate by one step clockwise. Table shows the pulsing sequence of windings when bit D0 is in 0 level the coil A 1 is energised, and so on. Fig the schematic of the stepper motor windings. The stepping action is achieved by proper combination of fields. The common step sizes range from 0.9 to 30 degrees.
![stepper motor interfacing with 8255 pdf stepper motor interfacing with 8255 pdf](https://image3.slideserve.com/6728410/8255-ppi-l.jpg)
It has 4 windings arranged such that instead of running in the usual continuous fashion the motor rotates in precise steps, from one fixed position to another. A stepper motor control is a specially constructed DC motor.
![Stepper motor interfacing with 8255 pdf](https://kumkoniak.com/71.jpg)