MiniDaq assembly instructions.
Construction notes: This kit requires good soldering techniques
due to its small size.
Tools necessary: A fine tip soldering iron and a good wire cutter.
Recommended tools: Mechanical clamp-known as a third hand, fine solder wick to remove excess solder.
Caution: Integrated circuits are static and heat sensitive. Do not apply too much heat with your soldering iron when installing these parts. Please take precautions while handing IC's. To protect against static electricity, ground your body before handling these parts.
Manual in Acrobat PDF format.
Frequently Asked Questions FAQ list.
Start by installing the IC's and the resistor pack. Observe proper orientation for pin 1.
U1 - MAX186
U2 - MAX1044
RP1 - 10K ohm isolated resistor pack
Install capacitors C1, C4 and C8.
C1 - .1uf monolithic capacitor. The printed value on the capacitor will normally be 104, denoting a .1uf value.
C4 - .01uf monolithic capacitor. The printed value on the capacitor will normally be 103, denoting a .01uf value.
C8 - .1uf monolithic capacitor. The printed value on the capacitor will normally be 104, denoting a .1uf value.
Install the resistors R2, R3, R4 and R5.
R2, R3 - 22 ohm
R4 - 47 ohm
R5 - 1K ohm
Install diode D2. Observe silkscreen markings when installing the diode. The black line on the diode is the cathode and should be installed in the same orientation as the silkscreen marking.
D2 - 1N4733A
Install the two 3 pin headers.
JP3, JP4 - 3pin 2mm headers
Since components will be installed on the bottom side of the PCB, trim off any excess lead length. This will allow the bottom components to lay flat and the plastic shell cover to close properly.
Start by installing resistor R1. Bend and pre-form the resistor as shown on the left. Cut the leads to a short length so the resistor lays flat on the PCB.
R1 - 47 ohms
Install diode D1. Bend and pre-form the diode as in step 6. Cut the leads to a short length so the diode lays flat on the PCB. Observe silkscreen markings when installing the diode. The black line on the diode is the cathode and should be installed in the same orientation as the silkscreen marking.
D1 - 1N4148
Install the capacitors C2, C3, C6, C7 and C9. Bend and pre-form the capacitor as shown in the picture in step 6. Cut the leads to a short length so the capacitor lays flat on the PCB. Observe the polarity of the capacitors before soldering.
C2, C3, C6, C7, C9 - 10uF tantalum, 6volts
Install capacitor C5. Bend and pre-form the capacitor as shown in the picture in step 6. Cut the leads to a short length so the capacitor lays flat on the PCB. Observe the polarity of the capacitors before soldering.
C5 - 22uF tantalum, 6volt
Install the two DB25 connectors. They are installed with the leads lined up with the pads on the PCB. Make sure the connectors are pressed flush with the board and that you have the correct connector gender before soldering. Pin1 on the connector should line up with the silkscreened pin1 on the PCB.
P1 - Male DB25 solder tail
P2 - Female DB25 solder tail
You should wash and clean the completed board before installing the two jumper shunts. We use water soluble flux solder here at EAS. This permits easy board cleaning. Radio Shack sells flux removing solvent made for pc board cleaning. Take a close look at all solder joints and touch-up any joints that look bad. A 2x or 3x magnifying glass helps to find any solder bridges.
INT of JP4 is for internal power from PC
EXT of JP4 is for external power - needed for low power laptops
UNI of JP3 is for Unipolar mode 0v to 4v input
BI of JP3 is for Bipolar mode -2v to 2v input
The standard configuration is usually set to internal power and bipolar mode.
Testing the MiniDaq.
Plug the MiniDaq P1 connector side to the PC parallel port. You can use a short 2 or 3 foot cable to connect the MiniDaq to your computer. Make sure the cable you use has all 25pins extended.
Download calibrt.exe and brun45.exe. Calibrt.exe is a DOS application and brun45.exe is the runtime library needed to run. Start the program and choose P to set the parallel port to the one you have the MiniDaq plugged into. If the board is working correctly, you should see changing data on the screen. Connect a 1.5 volt battery to analog input 0 (pin 1) and analog ground (pin14). You should immediately see the 1.5 volts displayed on the screen.
Test all the other channels by moving the battery lead to the other analog input channels and changing the displayed channel by choosing and setting "C".