Equipment controller with PC


Posted on Dec 12, 2012

Here is a circuit for using the printer port of a PC, for control application using software and some interface hardware. The interface circuit along with the given software can be used with the printer port of any PC for controlling up to eight equipment . The interface circuit shown in the figure is drawn for only one device, being controlled by D0 bit at pin 2 of the 25-pin parallel port. Identical circuits for the remaining data bits D1 through D7 (available at pins 3 through 9) have to be similarly wired. The use of opto-coupler ensures complete isolation of the PC from the relay driver circuitry.


Equipment controller with PC
Click here to download the full size of the above Circuit.

Lots of ways to control the hardware can be implemented using software. In C/C++ one can use the outportb(portno,value) function where portno is the parallel port address (usually 378hex for LPT1) and 'value' is the data that is to be sent to the port. For a value=0 all the outputs (D0-D7) are off. For value=1 D0 is ON, value=2 D1 is ON, value=4, D2 is ON and so on. eg. If value=29(decimal) = 00011101(binary) ->D0,D2,D3,D4 are ON and the rest are OFF.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Telephone Light Ringer
Stereo Electret Mic Preamplifier
Simple sine-wave generator has no low- or high-pass filters
how to build fridge door alarm
bass and treble control without any ic and transistor
picsoft
PLL SINGLE TONE DECODER
Sampling RF Power
Multi-output power supply circuit (MAX1902)
+5V + 12V boost power supply MAX761
XTR112 114 isolated transmit receive circuit diagram of the ring



Top