Building the ArduBat
Heat up your soldering iron ...

This page will take you step-by-step through assembling the ArduBat board.

You'll be starting out with all the parts shown to the left. See the full parts list.

You will also need to get some tools together...

  • A pair of diagonal cutters

  • Electronics grade rosin-cored solder

  • A magnifying glass ( for small part numbers )

  • A temperature regulated soldering iron, with a clean tip

The first group of parts to go on the board are the push-buttons and the 3 integrated circuits. Be sure to orient the notches at the "top" of each IC so that they match up with the diagram printed on the circuit board.

The CD4024 and the LM386 next to it are VERY close. Be sure that they are both fully inserted before soldering them in place.

This is also a good time to mount and solder the push buttons in their places. When you finish this step, your PCB should look like the picture to the left.

As you work on the circuit board, you can use the Layout Chart as a guide.

The next group of parts to get assembled are the resistors. For the most part, the values of the resistors are labeled on the circuit board, so they will be easy to place. Use the Color Codes Chart to match up the resistor values.

Two resistor values are not shown on the PC board though. The three LED resistor values can vary according to which LEDs you choose to use. For the kits and boards I make up, 680 ohm resistors are used.

The other resistor that has no labeled value is marked ..*** ..This resistor is not determined until the final project configuration is made. So this resistor's spot will remain empty for now.

If you have a kit from me, you will have some resistors left over. These will be used later, when the ArduBat board is configured, and the detector gain is set.

Once soldered in, clip off the excess resistor leads from the bottom of the PCB.

Now we need to install the small ceramic capacitors. This is where you might need the magnifying glass. These small capacitors are in 4 locations ...
  • C1 - .1uF ( 100nF ) marked as 104
  • C2 - .022uF ( 22nF ) marked as 223
  • C5 - .047uF ( 47nF ) marked as 473
  • C9 - .1uF ( 100nF ) marked as 104

Take your time with these, and be sure to get them right. If two of them get swapped during assembly, the board may not work ... and it will be hard to see later what had happened !!

Again, clip off the excess leads on the bottom of the circuit board as each capacitor is soldered into place.

Next we will install the three LEDs and the 9 volt regulator IC.

Each of these components has a flat side that faces towards the left ( towards the pushbuttons ) -- the orientation follows the printing on the circuit board. Be sure each of the LED's is oriented properly, or they won't illuminate !

I like to install the LEDs in the color order shown to the left.

Again, clip off the excess leads on the bottom of the circuit board after each of these components are soldered into place.

And now we install the last group of parts ... the electrolytic capacitors. These capacitors are polarized ... they need to be installed in the correct direction. The circuit board has a square pad with a + next to it ... this is where the + lead ( usually the longer lead ) of the capacitor needs to go. The lead that is marked with a stripe on the plastic cover of the capacitor is the negative lead ( - ), NOT the positive ( + ).

This can be confusing, but when you get them all installed correctly, they should look like the picture at the left. The two brown caps ( C3 & C7 ) are 220uF, the black one ( C8 ) is 470uF, and the two smaller blue caps ( C4 & C6 ) are 10uF.

( Notice that the PCB is turned around in this picture... )

When you think you have these installed, check them one more time. Then clip off the excess leads and save some of the clipped leads for use as jumpers.

The headers are now installed on the ArduBat circuit board. The long header strip needs to be carefully cut so that you have these 4 sections:
  • one 6 pin strip
  • two 8 pins strips
  • one 10 pin strip

You will have a small section left. Save this as we will use a two pin section later with the monitor earphone.

Use your Arduino UNO board as a jig to hold all the header strips in place.

Fully insert the longest set of pins for each of the header strips into the header sockets on the UNO. The shorter pin lengths are pointed up.

Note: Be aware that these pins can be sharp :-)

Now carefully align the ArduBat circuit board over all of the header pins and fully seat the board so that the pins all come through the outer two rows of header connections.

Check once again to be sure the board is FULLY seated, and level with the UNO circuit board.

You can now solder the outside pins on each of the header sections to keep it all anchored in place.

If you have a version 2.1 circuit board, don't solder the 5 volt pin until you do the next step...

If you have an older version 2.1 board, use a clipped capacitor lead to make a bridge link from the 5 volt inner pad to the pad with the header pin as shown in the image to the left. If your board is version 2.4 or later, you don't need this link.

Now solder all of the remaining header pins. Don't get any solder in the pads to the inside of the circuit board next to the headers ... they are used for configuring the board, so you want them left open.

This is a good time to install two jumpers that are needed to connect the output of the Simple Bat Detector circuit to the Arduino, and to connect the VIN from the Arduino to the power supply of the Simple Bat Detector circuit. Use the clipped capacitor leads you saved from an earlier step.

The first jumper is next to the digital pin marked as 2. It is jumpered to the pad labeled Bat Call. The second jumper is on the other edge of the board ...

The two jumpers installed are circled in red in the picture to the left.

At this point, I usually like to cut off the excess pin lengths on the top of the circuit board. These are sharp, so wear safety glasses against the flying clippings. I sometimes also put an adhesive bandage on my finger BEFORE clipping the leads, so I can safely use my finger to contain the clipped pins.

All that is left to finish the initial board assembly is the transducer, and the optional detuning coil - L1

If you are NOT using the transducer listed in the parts list, then DO NOT USE a detuning coil ! The coil that is used is specifically matched for the exact transducer in the parts list, and will likely not work for other transducers !

So, if you ARE using the listed transducer, and want to use the detuning coil, mount it at the location on the circuit board marked L1. This is not an ideal fit, as the coil lead spacing varies, and is many times too wide or too narrow.

If you have a version 2.1 circuit board, you will need to bend over one of the leads on the bottom of the board and solder it to a nearby grounded pad ... as shown to the left ... this corrects an error on the circuit board that went away in board version 2.4 and later.

Finally, we get to mount the transducer. If your transducer has the case connected to one of the connector pins, connect that pin to the pad closest to the Monitor pads.

Carefully insert just a little portion of the leads into the circuit board and solder them on the bottom side of the board.

Then GENTLY bend the transducer forward and away from the board to give a bit of an angle to the transducer's pickup pattern.

At this point, the initial construction of the ArduBat board is complete !


The next step ... Configuration !!


Tony Messina - Las Vegas, Nevada - email: T-Rex@ix.netcom.com