Instructions for v1.1
These instructions are for the newer v1.1 kit with a thinner PCB and slightly different components. It makes minor upgrades to the kit which reduce power usage. If the photos don't match up, you probably have a v1.0 kit and you should follow the instructions here!Lets go!
These instructions are for the newer v1.1 kit with a thinner PCB and slightly different components. It makes minor upgrades to the kit which reduce power usage. If the photos don't match up, you probably have a v1.0 kit and you should follow the instructions here!
Heat up your soldering iron to 700deg F, clean the tip and make sure your sponge is wet.
Lets go!
Bend the resistor into a staple as shown, and slip it in.
Start with the resistor RB. This resistor has a different value, 300K. The stripes are Orange, Black, Yellow, Gold. Place that on the left, next to the RB silkscreen.
Then place R1 this is a 10 or 20 megaohmresistor! The stripes are brown, black, blue, gold or red, black, blue, gold. Make sure you do not confuse this with R2 which is a 10 ohm resistor. Look under a bright light to tell which one has a blue stripe and which one has a black stripe. If you're not sure, a multimeter will help measure the resistance.
Finally, place R2 which a 10 ohm resistor. The stripes are brown, black, black, gold. Make sure you do not confuse this with R1 which is a 10 megaohm resistor. Look under a bright light to tell which one has a blue stripe and which one has a black stripe. If you not sure, a multimeter will help measure the resistance.
Check again to make sure you did not confuse R1 and R2. Really, you need to look under a good light and a mistake here will be difficult to determine later!
(oops forgot to take a photo here!) | Clip the resistors. |
Next are the two ceramic capacitors C1 andC3. Ceramic capacitors also have a nice property that they are symmetric/non-polarized. That means they can go in 'either way'. The capacitors are different values so make sure to not mix them up.
C3 is a yellow 0.1uF capacitor and has a "104" marking on it. C1 is the blue or orange 680pF capacitor and has a "681" marking on it.
Place the capacitors so that the 2 legs (leads) slide thru the two metal holes in the PCB (pads). The capacitor will sit flat against the PCB.
Next is the heart of the kit, a low voltage 555 timer chip. This one is called the TLC551. The important thing to note about the chip is that it is not symmetric. If it is put in wrong it will not work! Its also nearly impossible to fix if the chip goes in wrong so make triple-sure before you solder it in!
The silkscreen on the PCB has a little notch in the top. That notch indicates where the top of the chip is. If you look on the chip, there is a circle/dot imprinted in it on one end. There's also a TI logo at that side. Make sure the chip is inserted so that the top of the chip lines up with the silkscreen notch. Check the photo to the left if you're not sure.
Next is the transistor amplifier Q1 which is PNP type
Make sure the shape of the transistor matches the silkscreen shape as shown.
Next is the electrolytic capacitors C2
Electrolytic capacitors are polarized and must be placed correctly or the circuit will not work. The longer lead is the positive (+) one and must go into the pad marked with a + as shown.
The electronic components are soldered in, next it is time to attach the speaker.
There are two ways to go about it. I will show the easier version first which uses wires to attach the speaker. Then I will show the 'more elegant' but difficult version where the speaker is attached directly to the PCB.
Use the diagonal cutters to clip off 2 2-3" pieces of wires.
This is the more challenging way to attach the speaker but is a little more 'elegant' looking.
Prepare by finding the two big pads for the speaker.
OK no matter which way you attached the speaker we will move to the next step.
Now its time to do a quick test before finishing up. Place a AAA battery in the holder.
Slide the battery holder into the PCB (but do not solder it in). Make sure that the battery is aligned correctly. Putting in the battery backwards shouldn't damage the circuit but it's still not a good idea so try to get it right the first time. The back of the PCB has a silkscreen to help determine which way the battery goes in.
With the battery holder in place (but, again, not soldered in) touch both sides of the PCB. A squeaking noise should come out of the speaker! As you press harder/softer, the pitch will change. That indicates the circuit is working.
If its not making noise, try:
1. Wiggle the battery holder a little to make sure it's making contact.
2. Check that the switch is turned on.
3. Check that the components are correctly placed and soldered well. Re-touchup the solder points in case you have cold solder joints.
Once you are tested and happy, its time to finish up!
Remove the battery and place the battery holder on top of the components, as shown. Bend the leads a little so that it sits as tight as possible.
Solder in the battery holder, and clip the leads short.
Wrap the tape along the top of the pencil so that the beginning is at the silver metal tab on the PCB, as shown.
While you don't have to solder the tape to the metal pad, it doesn't hurt and it can sometimes give you a better connection so feel free to!
Then take the thumbtack and gently push it into the end of the pencil. You might have to twist it back & forth a little to get it all the way in. The thumbtack will grip the copper tape and also make contact with the graphite in the middle of the pencil to make the first half of the drawing sensor.
Next take 3 or 4" of copper tape and start wrapping around the bottom of the pencil, starting with the silver tab on the PCB and ending an inch before the end of the pencil. This will make contact with your hand and provide the second half of the sensor.
While you don't have to solder the tape to the metal pad, it doesn't hurt and it can sometimes give you a better connection so feel free to!
Page last edited March 08, 2024
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