Overview
It's a surface mount solder-it-yourself kit that drives 4 LEDs in a heartbeat-style blink pattern by cascading two 555 timers. It also is a terrible, terrible, awful layout. Especially if you like things to be straight and 45 and 90 and neat and tidy. Give it to yourself as a positive affirmation that you really do kick ass despite your oddities, or give it passive-aggressively to your "favorite" person.
Not you ordinary PCB! Traces with acute angles. A word that's backwards on the bottom silk layer. Mini-MELF diodes that like to roll off the table or launch out of your tweezers. Components at all angles. No reference designators on the silkscreen because gosh darnit they just junk up the PCB, don'tcha think? Guess you'll have to refer to the assembly diagram to figure out what goes where. And who doesn't love a constant reminder that they're #1?
The circuit is pretty special too, I mean, anything involving 555 timers is special. This circuit uses two of them - one provides the lower frequency roughly once-per-second pulse train, and the other is set up to output a higher frequency roughly 10 Hz pulse train. The first timer's output is hooked up to the RESET input of the second timer. So the high frequency timer's output is only on for long enough for 2 pulses, then it's off for the remaining of the 1 second. The result is a cool heartbeat-style LED blinking pattern! Thud-thud......thud-thud......thud-thud.
OK, just to prove we don't hate you _that_ much, the smallest components are 0805s, so it's not too bad though my old-ass eyes still prefer magnification. We color-coded them and include a key to what color is what value. We even give you EXTRA PARTS. We also included an ON/OFF switch because only devil blinky boards don't have them. We also included a second blink/no-blink switch so that you can have your LEDs solid on if you prefer. See? We actually truly love you in our perverse way.
Unpack Your Kit & Download/Print Assembly Diagram
Your kit has color-coded components and a flyer with the color key. We've given you some extra resistors, capacitors, and LEDs, so you may have left-overs when you're done. Go to the Documentation section of this project and download or print the assembly diagram. You may also want to cross-reference components with the schematic.
*Links to Schematic and Assembly Drawing are under Documentation
You'll note we did not print reference designators on the back. This was purposeful, just to make the kit a little more pesky. But it's good practice - not all circuit boards have enough room to mark reference designators. So think of it as building your surface mount troubleshooting and assembly skills!
Here's how to figure out which components go where:
- Understand your component values. The components are all color-coded. You can match them to the colors on the flyer to figure out their values. Or, if you have a multi-meter with sharp probe tips, you can poke right through the tape and measure resistance and capacitance directly. Also, the resistors actually have their resistance marked on the top if you have magnification or good enough eyes to see it! The leftmost 3 digits are the resistance, and the digit on the right stands for the number of 0s after. It's always in ohms. So "1000" means 100 ohms, "1203" means 120,000 ohms (or 120k ohms).
- Understand your reference designators. We've been SUPER NICE and put the reference designators for the resistors, capacitors, and diodes on the color card flyer. You can also look at the schematic, and match up the values with reference designators.
- Figure out where each component goes. Look at the assembly diagram, which shows you the reference designator for each component's position. Match up the reference designator, value, and position, and start soldering!
Solder 555 timers
Which solder/flux should I use? Lead-based solder will be easier to learn with, but lead-free is totally fine too (and better if kids are handling the solder, and more eco-friendly). We prefer to solder SMT components with water-soluble flux because it's more aggressive and wets out the solder much better, enables you to hit the solder with the iron a few times before it's gone and you get crystallized/cold joints. BUT BE SURE TO CLEAN IT OFF WHEN YOU'RE DONE. Water-soluble flux is more aggressive and can corrode boards if not cleaned off. It is also slightly conductive and will affect the function of your final circuit. Our next favorite is RMA (rosin mildly activated), and our least favorite for SMT work is no-clean. But if that's all you have, it's OK! Don't worry about it, just use it. More important is having a small diameter solder, to more easily control the amount applied. We like using 20 mil (0.5mm) or smaller diamter. We also love using flux pens, it's great for adding just a small bit of flux to a joint to reflow a cold one.
Now solder your 555s!
Note that these are directional! The line on the IC (chip) marks the "top" of the chip, pin 1 will be at the top left. The top of the chip is also noted by a "U" shape on the silkscreen (under the chip in these photos). Also, pin 1 is denoted by a dot.
Solder all of the resistors
Be sure to check with the color chart and assembly diagram to figure out which value goes in which position. We recommend keeping your resistors and capacitors in the tape, and only pulling out one value at a time as you're ready to solder it. This keeps them from getitng mixed up on your bench!
If you're soldering two kits at once, use the same technique. Solder all resistors of one value on both boards before going onto solder the next value.
We have given you one extra resistor of each value, in case you accidentally send it flying! The key is to hold your tweezers in a relaxed grip, with just enough force to hold onto the component.
Solder Capacitors
Same as above, don't take a component out of the tape until you're ready to solder it! Solder all of each value before proceeding to the next, to minimize the chance of mix-ups.
Solder on all the diodes
Make sure they are facing the right direction! The black lines are the cathodes, they go toward the white lines on the silkscreen. These are a little bit of an old-school glass style called mini-MELFs, they are perfectly cylindrial and like to roll off of your bench. You're welcome!
Solder the Switches
We didn't add these to the card because they should be self-explanatory. You can't screw these up.
Flip the board over and solder on the 4 LEDs
YES, you are skipping the battery holder for now!
Make sure the LEDs are facing the right direction! The white lines on the silkscreen should be matched to the veeeeery small dot on one side of the LEDs. You can see this in the photo below. You can also look at the underside of the LED, and note there is something that looks like a line with a dot on one side, which is the very pixelated approximation of an arrow. The "arrow" should point toward the white line. This is probably the trickiest part to get right, but you'll know if you got it when you power it up for the first time!
Flip the board back over and solder the battery holder
Yep, we save this for last so that you had a nice flat surface for the previous step of soldering the LEDs. Make sure the opening faces up (toward PS - I Hate You), otherwise it'll be difficult to get the battery in.
Clean off the flux!
This step can be important for this board. Especially if you've used a water-soluble flux, the residue can actually conduct enough to alter the blinking circuit! Crazy, huh? This has actually caused issues with production electronics, so now you know a true pro tip. Clean off your flux, even if it's rosin. No-clean might be OK, depending. For water soluble flux, use warm water. For rosin or no-clean, use 90% or higher isospropyl alcohol. In either case, it's also nice to blow off your board with canned air, to get any residual water or alcohol out from under components.
Troubleshooting
One of the LEDs don't light up:
- Check the direction of your LEDs! Did you solder them on in the proper orientation? If you need to change the direction of an LED, you can do this without damaging the LED if you're careful. Put your soldering iron to the side of the LED and add a bunch of solder until it blobs and touches both ends of the LED, and gently wipe the LED right off the board. If your LED is still on the solder blob on the tip of your iron, immediately whack the palm of your hand holding the iron against the table. This will cause the solder and the LED to drop off the tip, onto your table. Gently wipe most of the excess off of your LED and try again! We also give you an extra LED.
All of the LEDs don't light up:
- Check the direction of your LEDs per above.
- Check the direction of your battery.
- Check the direction of your 555 timer chips.
- Check the direction of your mini-MELF diodes.
The LEDs blink, but in a weird/wrong pattern:
- First, take your battery out and make sure your circuit board is clean, per the above step. Try it again. If it still is weird, go onto the following steps.
- The first one minute may in fact have a slightly different pattern, there can be a small "break-in" period. (It's an interesting effect due the initial voltage & internal resistance of a fresh battery). Just wait and see if it changes.
- Check the direction of your timer chips and mini-MELF diodes.
- Check your resistors for the correct values in the correct places. You can look at the numbers written on top under magnification, and you can also turn the circuit OFF, and measure each one's resistance with a multi-meter.
- Check your capacitors for the correct values in the correct places. The two most important ones are the 2.2uF C4 and the 10uF C1. There's a difference in the sizes of those capacitors, C1 should be the biggest/tallest one on the board. C4 should be the second biggest. Double-check the assembly drawing. You can also measure the capacitance in-circuit if you have a multimeter, but note you'll get slightly different values than "ideal" out-of-circuit values. You should still be able to verify that they're in the correct positions.
Insert Battery and Turn On!
Match the + side of the battery to the + side of the battery holder.
There are 2 switches. When looking at the back of the board, the ON/OFF switch is on the left and the BLINK/SOLID switch is on the bottom right.
Place Magnet or Adhesive Pin (optional)
The magnets are very strong, use caution when handling. Place magnet on the battery holder, this will only work if the battery is installed. You can then attach it to any magnetic surface like your fridge.
If you'd like to wear your badge, you can use the ahdesive back pin provided in your kit. Remove the strip covering the adhesive and firmly press to the battery holder. You can then pin the badge to your shirt.
Backstory
I came up with this project after reading this snarky tweet about how the RPi Pico was "literally unusable" because a trace was at an odd angle. Having been designing circuit boards for 20+ years, I thought the resulting thread was hilarious. There were also pictures of other really weird cringe-worthy layouts, and I thought "Heh, it would be fun to do a terrible layout on purpose, as if you just threw a handful of components on a board and they stuck wherever they landed." Then I thought "Hey, Valentine's Day is coming up, I could make it a snarky Valentine because that holiday is total BS anyway." And thus, PS - I Hate You was born!
First, you'll note that there's not a perfect 45 or 90 degree angle anywhere on the thing. In fact, there are even some traces with ACUTE ANGLES.
We purposefully left reference designators off of the silkscreen. Guess you'll have to refer the assembly diagram files to match components to their places.
However, in spite of all that, we kind of think this board looks cool and we're stoked with how the graphics came out. And who doesn't love some 555 timer shenanigans? We're using one timer to make a low frequency, about 1 Hz, pulse train with a about a 25% duty cycle. We're using the other 555 timer to create a continuous roughly 10 Hz pulse train. The low frequency timer's output is hooked up to the high frequency timer's RESET pin, so the high frequency timer output is on only long enough to let 2 pulses out. The result is a twice-per-second heartbeat-style pulse that's used to blink the LEDs.
Of course, we recognize that not everyone loves blinky things. So we have a "solid on" switch that bypasses the timers, and just runs the LEDs straight off the battery voltage. We also have an ON/OFF switch because we don't actually hate you _that_ much.
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