Engineered for greatness by PaintYourDragon, this watch squeezes over 1000 full time displays out of a coin battery, and a 1+ year 'resting' lifetime, so you can use this as a day-to-day time keeper.
Engineered for greatness by PaintYourDragon, this watch squeezes over 1000 full time displays out of a coin battery, and a 1+ year 'resting' lifetime, so you can use this as a day-to-day time keeper.
Tools List
Tutorials
Tools
There are a few tools that are required for assembly. None of these tools are included. If you don't have them, now would be a good time to borrow or purchase them. They are very very handy whenever assembling/fixing/modifying electronic devices! I provide links to buy them, but of course, you should get them where ever is most convenient/inexpensive. Many of these parts are available in a place like Radio Shack or other (higher quality) DIY electronics stores.Any entry level 'all-in-one' soldering iron that you might find at your local hardware store should work. As with most things in life, you get what you pay for.
Upgrading to a higher end soldering iron setup, like the Hakko FX-888 that we stock in our store, will make soldering fun and easy.
Do not use a "ColdHeat" soldering iron! They are not suitable for delicate electronics work and can damage the kit (see here).
Click here to buy our entry level adjustable 30W 110V soldering iron.
Click here to upgrade to a Genuine Hakko FX-888 adjustable temperature soldering iron.
You will want rosin core, 60/40 solder. Good solder is a good thing. Bad solder leads to bridging and cold solder joints which can be tough to find.
Click here to buy a spool of leaded solder (recommended for beginners).
Click here to buy a spool of lead-free solder.
You will need a good quality basic multimeter that can measure voltage and continuity.
Click here to buy a basic multimeter.
Click here to buy a top of the line multimeter.
Click here to buy a pocket multimeter.
You will need flush diagonal cutters to trim the wires and leads off of components once you have soldered them in place.
Click here to buy our favorite cutters.
Strangely enough, that's the technical term for this desoldering vacuum tool. Useful in cleaning up mistakes, every electrical engineer has one of these on their desk.
Click here to buy a one.
Not absolutely necessary but will make things go much much faster, and it will make soldering much easier.
Pick one up here.
Parts List
- TIMESQUARE PCB - half thickness black PCB
- ATMEGA328P - preprogrammed microcontroller
- DS1337 - 8 pin real time clock chip
- 32.768KHz Crystal - thin silver cylinder
- Right angle buttons - two for either side
- 20mm coin battery holder
- 0.1uF ceramic capacitor - yellow blobby
- 1 x 10K resistor - brown black orange gold
- 8 x 47 ohm resistor - yellow violet black gold
- 1.5" 8x8 matrix (not shown)
- Silicone rubber watch band
- Clear plastic cutout back
- CR2032 Coin cell battery (battery not included as of October 22nd, 2015)
Kit Assembly
Bend the resistor into a staple and slip the wire leads into the two holes so that the resistor covers the outline labeled R10 in the bottom right corner shown here
With your soldering iron heated up and ready, solder in both leads of the resistor. To do this, heat up the round ring pad and the wire lead at the same time for 2 or 3 seconds, then dip the end of the solder into the heated joint to melt it in.
Then remove the solder and the soldering iron.
Ceramic capacitors, like resistors, are not directional. So put it in any way it fits, next to the R10 resistor, so its surrounded by the C1 outline
Then bend the leads and flip over the board.
All the resistors are the same 47 ohm value - Yellow Violet Black Gold
Here we placed and soldered all 8 at once but you can go one at a time if you want to take it a little slower!
This chip is the "real time clock" - the timekeeper. It is a ultra-lo-power circuit, whose only task is to keep track of the time, so its pretty good at it. It's possible to have the main microcontroller chip (the next one we'll do) keep track of the time, but its not as good at it (both in terms of power and precision) so we splurged on having a seperate RTC
The important thing about chips is that they are not like resistors and capacitors in that they can't be placed 'either way'. It must be placed the right way or the chip wont work. Look for the end of the chip with a notch and a dot. These must match up the silkscreened image on the PCB so make sure the notches line up.
The chip is an ATMEGA328P that has been pre-programmed at the Adafruit factory to have an Arduino-compatible bootloader and our default watch display code.
To begin, flatten the pins to make them more parallel || shaped intsead of A shaped. Hold the chip in your hand and press all the pins one side at a time against a flat table.
Then when you press it into the holes, make sure each pin has made it into a matching hole, and its sitting flat against the PCB
Like the RTC, this chip must be put in the right way. The notch on the chip must go on the left side as in these photos. Check twice to make sure you have the chip in right!
The battery holder does have a special way it must go, make sure you can slide the battery in by having the open side facing out
The crystal can go in either way, its symmetric, like the resistors
Also, solder and clip the two crystal pins
Both go on either side of the board, and they'll snap in.
Then flip the board over and solder in all 4 pins of each
The LED matrix is what you'll be looking at - 64 individual LEDs in a plastic case.
The Matrix is not symetric, it must go in the right way on the right side.
Look for the writing on the side of the matrix, this side must go on the side of the PCB with a dot as you see here. Also the matrix goes on the OPPOSITE side of the other parts!
Check that the 28-pin microcontroller pins aren't in the way of the matrix, it should sit nice and flat
You can clip the leads but you don't have to (they're less long than the height of all the other parts!
When you've got it all in, you may need to pull/press the band around the PCB to have the 'nubs' fit into the notches that are molded into the band
ADJUSTING FIT
After you've assembled your watch there are a few ways to change the fit of the band around the PCB. First is trimming down the nubs on the PCB. These are there to help keep the board inside the rubber band. However, they may be long depending on your wrist size, and band (all the bands are slightly different)
Simply trim them down a millimeter at a time to help avoid them from sticking out too much
OTHER TWEAKS
Kapton tape is a heat-resistant and electrically insulative tape that's used a lot in electronics. This isn’t included with the watch, but if you’ve been in this hobby for a while there’s a good chance you already have a roll handy. Wonderful stuff.
One or two layers of Kapton tape applied to the watch face make it less prone to washing out under bright light. The tape’s color is similar enough to the red LEDs that they shine through with little difficulty, while most ambient light is blocked.
Rubylith film (from a decent old-school art supply store) would probably work as well, if not better.
Setting the Time
Time Display Modes
Tap →⌚ or ⌚← tap
Hold the left or right buttons (not both) for 2 seconds to move back or forward through modes.Hold →⌚ 2 sec or ⌚← hold 2 sec
The sequence of modes is:↪Marquee↔Binary↔Moon Phase↔Battery Gauge↩
Marquee mode
Inspired by the famous Dow Jones news ticker, this scrolls the current time from right to left.Tap either side button while active to switch the display from time to date. Tap again to show the time.
Binary mode
Bright dots represent a binary “1,” dimmer dots are “0.” “Off” dots separate the digits.The hour (1 to 12) is shown as four 2x2 pixel blocks across the top.
Minutes and seconds are 1-pixel blocks, with the high and low digits separated for easier reading (3 bits and 4 bits, respectively).
The display at left shows 4:09 and 12 seconds.
Moon Phase mode
Displays the current phase of the moon.The resolution is limited somewhat by the screen. It’s generally accurate, but this is not a medical device — do not rely on this data if you are prone to lycanthropy.
Battery Gauge
This displays the approximate battery level.Frequent button presses may temporarily lower the battery voltage more than this display indicates. After assembling your watch, you might run through the first battery pretty quickly in your enthusiasm to show everyone. If it seems to have suffered a premature demise, allow the watch to rest for a few hours, or try a fresh battery.
Uploading New Firmware
You'll need the Arduino IDE, and also some knowledge of how to read and write Arduino code.
To program the watch itself, you'll need an FTDI cable or FTDI Friend. This will connect your computer to the watch. If you're using an FTDI cable or anything other than the Friend, you'll also need some extra long header to press-fit.
Simply place a 6-pin extra long header into the FTDI connector and slip the other end into the top of the watch PCB, to match this photo. Be sure to have a battery in the watch, as it does need to be powered while programming!
Rename the folder to Watch (check that the renamed folder contains the Watch.cpp and Watch.h files) and install into the arduinosketches/libraries folder. For information how to use and install libraries, see our tutorial!
Restart the IDE
When programming, select Lilypad Arduino w/ ATmega328 as the "board" type
Downloads
This guide was first published on Nov 30, 2012. It was last updated on Nov 30, 2012.