EAS MINI DAQ
Intro
EAS MINI DAQ is an 8 channel, 12bit analog to digital converter for the IBM PC, with 4 digital
input channels and 7 digital output channels. It connects to the parallel port of your PC and
requires no external power. Typical uses are, high speed strip chart recording, data logging,
process control, home automation, an electronic workbench, ect. When used with Labview, It
becomes a very versatile instrument for process control and data logging. With the supplied
software libraries, you can create custom control and data logging applications, in C, BASIC,
and Excel.
Construction notes
This kit requires good soldering techniques due to its small size.
Tools necessary: A fine tip soldering gun and a good wire cutter.
Recommended tools: Mechanical clamp-known as a third hand, fine solder wick to remove
excess solder.
Caution:
Integrated circuits U1 and U2 are static and heat sensitive. Do not apply too much heat
with your soldering iron when installing these two parts. Please take precautions while handing
U1 and U2 to protect against static electricity, ground your body before handling these parts. It
is also very difficult to take apart the shell coverings once they are snapped together. Leave this
as the last assembly step.
Start by installing the top half components first, U1, U2, resistor pack RP1, etc. Make sure you
have proper alignment before soldering. Pin 1 of U1 and U2 should be on pin 1 on the PCB
board. Diode D2 follows markings on PCB board. Install JP4 and JP5 after the rest of the top
half of parts have been installed. You will then be able to lay the board upside down on a flat
surface and allow the headers to be held in place by the board weight while soldering.
Note: since components will be installed on the bottom side, trim off excess lead lengths. This
will allow the bottom components to lay flat and the shell covering to close properly.
After the topside is done, be sure to cut any excess lead lengths before starting on the bottom.
The bottom side requires enough exposed component leads to be soldered and bent 90 degrees.
Another method is to pre-form and place the components before soldering. Remember it is best
to heat the leads first before applying solder, then apply solder only to the leads, not to the
soldering tip. Be sure to observe proper polarity for items 2 and 4 on parts list. These are
tantalum capacitors that have markings for positive or longer leads to indicate positive side.
Install D1 and R1 by cutting and pre-forming leads before soldering.
The Jumper setting is
INT of JP4 is for internal power from PC
EXT of JP4 is for external power - needed for low power laptops
BI of JP3 is for Unipolar mode 0v to 4v input
UNI of JP3 is for Bipolar mode -2v to 2v input
The DB25 connectors are installed with the leads lined up with the pads. Make sure the
connectors are pressed flushed to the board before soldering, and that you have the correct
connector gender before soldering. This will be impossible to remove if you get it wrong.
