X Y Plotter Interface

DI di, 1 D2 • clk 2 D3 air 2 D9 • relay 1:15 • XI • 0000 0 0 BC 547 044 X Y PLOTTER INTERFACE N1.-N4 =ICI = 7400 N5...N8= IC2 = 7086 FF1,FF2 = IC3 = 7473 N9...NI2 = IC5=7486 FF3,FF4= IC6 = 7473 5 IC6 05V GENERAL INTEREST This low-cost circuit can drive two stepper motors and a relay by digital control data supplied from a computer. It can also detect the position of two microswitches and supplies logic levels back to the computer as positional information. This combination makes the interface ideal for use as an X-Y plotter or for building a buggy-style robot. Circuit IC1 is configured as two set-reset (S-R) latches to provide contact debouncing for the two microswitches, S1 and S2, whose position is detected by computer reading port bits D5 and D6. The relay drive circuit around T1 may be used to switch a solenoid-operated pen on and off under the control of port bit 4. Motor drive is provided by XOR gates N5-N12, bistables FF1-FF4 and integrated motor coil driver I...