Bat Detector Project

EQUIPMENT & RESOURCES

Bat Detector Kit

Philips Head Screw Driver

Small Slotted Head Screw Driver

Soldering Iron

Solder

 

 

Using laser cut acrylic, PLA 3D printed parts, and our custom PCB...assemble an awesome little bat detector and go find some bats!  

This project is all about the outdoors! We love to do this project in our 'outdoors' workshop. You will need to solder the PCB and then assemble the parts. If you prefer, you could make your own custom case! (Look at the end of this guide for the 3D files, use them as a staring point)


Before you get started...

This kit is made up of two parts; the printed circuit board (PCB) and the case. To assemble the PCB you will need to be comfortable with a little bit of soldering...if you haven't done this before, then take a look at this video to get you started. 

You should make sure you solder your board in a place that has some good air flow (or a fume extractor) so you don't breathe in those nasty soldering fumes! 

STEP 1 - THE PCB PARTS

Opening the kit pouch you'll find the PCB and the various electronic parts, as well as some3d printed and laser cut casing.

Lets get going with the assembly of the electronics. We will start with the resistors (these limit the amount of current running through the circuit) then move onto the capacitors (in this circuit they 'clean' the signal from the ultra sonic microphone to the headphones), we will then move onto the mic and headphone socket and finally the LED strip and battery 'clip'.

The board has two sides... a top, and a back. 

For this guide, the TOP will be the side with the words 'Bat Detector' on, the BACK is the side with the '#IHAVEAMAKERMINDSET' on. Typically PCBs are printed so that there is an outline of the component showing where each should fit. Usually with a letter or number. 

Some components on this board need to be put into the holes a certain way round. In this case, we have shown where the NEGATIVE (or ANODE) should go. Don't worry... we will show you when you need to know!

STEP 2 - The resistors

There are 3 resistors in this circuit. They are named; R1, R2 and R3. R3 is slightly different as you are able to adjust the amount of resistance it creates. R3 controls the volume of the headphones! 

Resistors can have different values, the way we can figure out the 'resistance value' of each is to understand the colour code which is printed on the resistor itself! You can find out more by watching this video, and if you want to read the value yourself... use this guide here!

Resistor 1 (R1) - (BROWN,GREEN,BROWN,GOLD)

To help when soldering the components into the board (once you have pushed the legs of the component through the correct holes) it is really helpful to bend the legs back a bit to stop the component from falling out!

1. Check you have the correct resistor value

2. Bend the resistor legs at 90 degrees to the resistor, about the same distance apart as the holes you are about to push through.

3.  Push the resistor through the holes at R1 and bend them back slightly on the back of the board. There isn't a positive or negative leg on these resistors,  so don't worry which way round they go (as long as the go through the top of the board to the back) 

4. When you are happy with the placement, solder the two joints on the back of the board. 

5. Use wire cutters to cut off the excess length from the legs.

 

Resistor 2 (R2) - (RED,RED,BROWN,GOLD)

Do the exact same thing with the second (R2) resistor. 

1. Bend the resistor legs at 90 degrees to the resistor, about the same distance apart as the holes you are about to push through.

2.  Push the resistor through the holes at R1 and bend them back slightly on the back of the board. There isn't a positive or negative leg on these resistors,  so don't worry which way round they go (as long as the go through the top of the board to the back) 

3. When you are happy with the placement, solder the two joints on the back of the board. 

4. Use wire cutters to cut off the excess length from the legs.

 Resistors R1 and R2 soldered in place

Resistors R1 and R2 soldered in place

Resistor 3 - The Variable Resistor / Potentiometer

This resistor has 3 legs, and will only fit one way. Phew! 

On the top of the resistor is a small slot for a screw driver, we can use this to set the volume of the headphones later. 

If you look closely at the top of the component, you will see is spins about 270 degrees, not all the way around! Make sure when you are adjusting this later, that you don't twist it round too much.

1. Place the resistor into the correct holes

2. The resistor wont push all the way through, instead it will sit just above the board...this is fine!

3. On the back of the board, gently bend the legs a little to help hold it in place.

4. Solder the legs, there is no need to use the cutters here as the legs are already quite short!

STEP 3 - HEADPHONE SOCKET

While were are down in this corner, lets solder in the headphone socket!

This is very similar in style to R3, in that it will sit just above the board, with the little legs poking through the back side of the board.

This component is doing two things... 

1. Passing the signal to the headphones to make a sound in your ear

2. Acting as the switch in the circuit.

This means that in order to turn on your bat detector, you will need to plug your headphones into the socket... else it wont power on!

Because the legs are quite short on this component, you may find using a little bit of tape on the top of the board will help to hold the socket in place while you solder the joints.

1. Place the component into the correct holes

2. OPTIONAL - use tape to hold the part secure

3. Solder the legs, make sure you don't use too much solder here. You don't want to join the legs together or 'bridge' the joints.  Use our photo as a guide.

STEP 4 - C1,C9 CAPICToRs

For this step we will use one of the BLUE capacitors.

This component can go into the board in either direction.

Place the component into the correct holes

Treat this like the resistors you soldered earlier...

1. Place the capacitor into the correct holes

2. On the back of the board, gently bend the legs a little to help hold it in place.

3. Solder the legs in place on the back of the board

4. Use the wire cutters to remove the excess leg length

C9 uses the other blue capacitor...so give that a go too! 

STEP 5 - C2 CAPICToR

The small (single) yellow capacitor fits into C2. It also doesn't matter which way this one is placed.

1. Place the capacitor into the correct holes

2. On the back of the board, gently bend the legs a little to help hold it in place.

3. Solder the legs in place on the back of the board

4. Use the wire cutters to remove the excess leg length

 

STEP 6 - C3 & C4 CAPACITORS

Now you are getting more confident...lets do the two 'disc' shaped capacitors (C3 and C4). 

These can also go either way round, and will fit neatly next to the resistors we did earlier.

For each capacitor...

1. Place the capacitor into the correct holes

2. On the back of the board, gently bend the legs a little to help hold it in place.

3. Solder the legs in place on the back of the board

4. Use the wire cutters to remove the excess leg length

 

STEP 7 - c5 & C7 Capacitors 

Okay, these capacitors have 'polarity' so will need to be put into the PCB in the correct direction.

Also, these capacitors look very similar to the other 'barrel' capacitors. So.. we need to make sure we use the correct ones!

The value for c5 and C7 is 10uF (or ten micro farads)

The value of the capacitor, and the NEGATIVE or ANODE are printed onto the side of the component. Also, as an extra help, one of the legs are shorter. The light stripe and the short leg mean that the leg is the NEGATIVE, (also known as the ANODE).

Once all the 'barrel' capacitors are in place, all of their negative/anode legs should point in the same direction - towards the bottom edge of the PCB.

The PCB also has the negative marked, this time by a square hole. So...

1. Make sure you check the value of the capacitor is correct (10uf)

2. Find the negative/anode leg and make sure it goes through the correct 'square' hole in the PCB.

3. Solder the component and wire cut the excess leg length

Repeat this for C7 too.

STEP 8 - c6 Capacitor

Treat this capacitor like C5 and C7. 

This time you are looking for the 220uf value printed on the side.

Once again follow these steps...

1. Make sure you check the value of the capacitor is correct (10uf)

2. Find the negative/anode leg and make sure it goes through the correct 'square' hole in the PCB.

3. Solder the component and wire cut the excess leg length

Repeat this for C7 too.

STEP 8 - c8 Capacitor

This is the last (and biggest - in size and value) capacitor.

You should have a 470uf capacitor left, this is capacitor C8! Just like the others...

1. Make sure you check the value of the capacitor is correct (10uf)

2. Find the negative/anode leg and make sure it goes through the correct 'square' hole in the PCB.

3. Solder the component and wire cut the excess leg length

STEP 10 - THE IC's

IC stands for Integrated Circuit. Basically, tiny components all housed in a rather neat little container (the black rectangular thing), with legs that are set distances apart which we will solder to.

These components are slightly more difficult to solder (and why we leave them to now to do... so you get some practise in before hand!)

The key to correctly soldering ICs into the PCB is to make sure you aren't heating the component up too much... essentially... be quick!

ICs generally don't like too much heat, so when soldering, make sure you only apply the soldering iron for a short time, and take breaks between each leg to let the part cool a bit.

You will also notice that on the PCB we have drawn an outline of the IC, with a little dimple on the top edge of the part. This matches up with either a circle/dot or dimple on the top edge of the IC itself. If a component looks like it has conflicting dimples and dots... go with the dimple!

The legs on the ICs are spread wider than the holes on the PCB, so will need a little gentle effort to get them into the PCB correctly. Don't push hard on the legs, they are very delicate! Follow the steps below

1. Check the dimple/dot lines up with the markings on the PCB

2. Push one side of the legs through first

3. Press the IC towards the legs that are already in the PCB, then push the remaining legs in. This will help hold the IC onto the board when you turn it over to solder.

4. Solder the top two legs on either side first. Turn the board the correct way round and check the IC is sitting against the PCB (sometimes they drop a little).

5. Turn the PCB to the back and solder the remaining legs, working down the legs allowing time between each soldered leg.

Do the same for each of the ICs. Leave the larger IC until last.

STEP 11 - UTLRASONIC MIC

For this component you will need to flip the PCB over and push the part through...the wrong way round!

We do this so that the mic is on the opposite side of the circuit... we don't want to pick up our breathing or talking!

The mic legs can go either way round.

Solder the part into place, but be careful when cutting the legs as they are slightly thicker, can can ping off into eyes and faces. We find it easier to point the PCB to toward the ground to cut these legs off.

STEP 12 - BATTERY CLIP

*EDIT  The Version 4.0+ boards have additional holes next to the 9v markings. This is to provide extra strength to the wires. Simply push the wires through the holes from the back to the top of the board, then feed the wire into the correct hole in the PCB.

The power clip wires will solder into the space on the bottom edge of the board marked with a 9V.

The negative wire goes through the square, the positive through the circle.

You may need to use wire cutters to clip the ends of the soldered joint, to make sure the battery doesn't short out where the wires could possibly touch.

STEP 13 - THE LEDs

This step is a little unconventional, but works REALLY well in this kit.

LED stands for Light Emitting Diode. A diode only allows the current in a circuit to follow in a certain direction (like a one way street), so its important to get the strip the correct way round...else no light up ... booo.

Rather than have loads more things to solder in the same way, w thought we would change things up a bit!

Using strip LEDs with sticky tape, we can get a super low profile effect which works really well with the case. 

When you plug your headphones in, the case will light up! Ooooo!

So..

1. Find the end of the LED strip that has the 12v/+ symbols on (make these line up with the big square copper pads), there could also be a set of arrows (make them point to the bottom of the PCB)

2. Turn the board over so the back is pointing upwards.

3. You will see, under the ultrasoinc mic, there are two copper squares (we call them 'pads'). You will need to stick the LED strip so that the copper parts on the strip overlap with the pads on the PCB.

4. First add solder to the pads on the PCB, use a little more than you have done for the other parts, you want a good 'hill' of solder to work with here!

5. Next, apply solder to the pads on the LED strip, you will need to add about the same amount of solder here too.

6. Then, and this is the tricky part, you need to heat both the PCB pads (and solder) and the solder on the strip then add extra solder to both at the same time. The aim here is to 'bridge' the pads from the PCB to the strip.... not the PCB to PCB...

Take a look at the last image in the slideshow below for what you are looking for. It may take a couple of tries, but it does work!

STEP 14 - TEST

Now its time to test out your board before we assemble the case!

Plug your headphones into the socket and the device will light up, if you rub your fingers infront of the ultrasonic mic, it should pick up the sound and convert it into audible 'clicks' from the headphones!

If the sound is too quiet, use a small slotted screw driver to adjust the volume by turning R3. The resistor will turn between 10 o'clock and 8 o'clock with the 10 position being the loudest.

STEP 15 - ASSEMBLE THE CASING

James Hannam