DIY TiX Clock

Here's my instructable for a DIY TiX clock.  It is powered by an AVR microcontroller.  The display is made up using a piece of reflector grid you find covering office lights, some smoked perspex, a diffuser and a bunch of LED's.  The Idea came from the Tix clocks you can buy at various places on the web, but nothing beats making it yourself.  It is a talking point in the lounge and once you are used to reading it, you can tell the time in a jiffy.

Step 1: The Electronics

The first prototype was made using Vero strip board.  The layout on strip board is fairly straight forward.  The Transistors in the top left are row drivers and the IC's on the right are  transistor arrays that are the column drivers (see circuit diagram at the end of instructable for more info).  This allows me to get a bit more current to the LEDs to make them brighter.  The Transistor array IC's can be replaced with transistors if you like.  You will find circuit diagrams and software at the end of this instructable with which I have included an Eagle PCB layout design as well for a single sided board that combines the controller and display board into one.

Note that if you etch your own PCB the LED's are mounted as normal thru hole components but the IC's, links and other components are placed on the copper side of the board.  The LED's and links will need to be mounted first as the AVR covers some of the LED solder points.  Details in the pictures.

Step 2: The Display

The display is made up of a sandwich of the display Board, The square reflector, a diffuser and a smoked perspex window.  You can place a sheet of tinfoil under the LED's to give more reflection, just make sure you cut a hole in tinfoil around a legs of each LED so it doesn't short things out.  I also sanded the lens of each led to distribute the light more.

The first three photos show the strip board version, the remainder the etched PCB version.

Step 3: The Case

For the case, you can use pretty much anything.  I used Rimu, a native timber to New Zealand.  I used a mill to cut out tracks and recesses for the "Sandwich" of the board, reflector, diffuser and window to sit in and the whole assembly slides in from the bottom.  There is also a thin recess for the rear of the clock to sit in, this is made from a thin sheet of plastic.  Buttons to press the switches were turned up on a lathe.

Step 4: The Final Product and Files

Parts List:
Q1-Q3 BC548
LED1-LED3 5mm High Intensity Blue LED
LED4-LED12 5mm High Intensity Red LED
LED13-LED18 5mm High Intensity Orange LED
LED19-LED27 5mm High Intensity Green LED
R1-R4 100k 1/4w Resistor
Q4 32.768 kHz Crystal
C1 4.7uF 10V Electrolytic Capacitor
C2,C3 10pF Ceramic Capacitor
IC1 ATMEGA16 AVR Microcontroller
IC2,IC3 TD62304 Darlington Transistor Arrays (these could be replaced with standard transistors)
S1-S3 Momentary Push Buttons

Enjoy! and vote for me!

Comments

[Foo_Plinger]

I have gone through quite a bit, and I currently have one of your boards (eagle file sent to china and printed) with everything soldered on, and it is somewhat running. Currently, no led's in the column/row (LED 3,6,9,12,15,18,21,24,27) are lighting. I just spent 3 days figuring out how to turn of JTAG debugging, and i am fairly certain it is off (lfuse 0xE1, hfuse 0xC9). Without seeing all of the LEDs lit, I am unsure how setting the clock is supposed to work. Am I to hold down the button on SET and use the UP or DOWN button? Should I click the set button a magical, but unknown, amount of times until something tells me i am in the SET mode? I feel like I am close, and i am begging for help, this has taken me literally years to get to this point.
I actually have 5 boards, the second one I soldered all the LEDs to the wrong side, silly me, I thought they would go where the silk screening was.

[gweeds]

Hi There,

JTAG definitely needs to be off, if you are missing LED's lighting up then it is not off. I am not sure of the hex values the fuses should be at, I use Bascom to program my AVR's, it has tick boxes for turning settings on and off and then sets the fuses appropriately. Setting the clock is done by pressing the set button, each press of the set button steps through the setting sequence; Hours, Minutes, Update delay. The hours and minutes should flash when setting and the update time flashes the hours in a particular way and the update time is displayed by the minutes section.

[gweeds]

Hi, I have now made this into a product with some improvements - check it out at www.tixclock.shop

[Foo_Plinger]

I don't know anything about a lot of these parts, and I was unable to find exact matches for some, and some you list don't have Volts specified or what form they should be in. Would this list of parts work?

Transistor BC548B TO-92 Transistor NPN Switch

Part no.: 254781
Manufacturer: Major Brands
Manufacturer no.: BC548B


32.768 KHz Tunning Fork

Part no.: 14584
Manufacturer: Jameco Valuepro
Manufacturer no.: CY32.76

Capacitor Ceramic Disc 10pF 50V ±20%

Part no.: 15333
Manufacturer: Jameco Valuepro
Manufacturer no.: DC10/50

4.7uF 25 Volt Radial Capacitor

Part no.: 2143460
Manufacturer: Jameco Valuepro
Manufacturer no.: R4.7/25


Transistor Darlington NPN 50 Volt 0.5 Amp 16-Pin PDIP

[DanielH582]

Is the jp2/isp the usbasp programmer?

[BEHROOZK2]

you are a true winner!

[robkirk]

Compact version. When making the led grid, miss the square separating the digits if you want it smaller.

[gweeds]

Hmmm, maybe I got the JTAG fuse bit around the other way. Change the JTAG fuse bit, reprogram and see what you get.

[robkirk]

one last thing is id love for it to be 3 second instead of 5 :/ :)

[gweeds]

Hi Rob? 3 seconds instead of five for the change time? is that what you mean?

[robkirk]

hiya gweeds if you ever get the time please could you do the 3 second change time tweak and upload the hex? many thanks. Also if you had a variable resistor pot on the positive feeding the 3 bc transistors would this be able to dim the leds? and could you even incorporate a photocell to this and have it done automatically.

[robkirk]

Yes gweeds i thought that 3 seconds would be about the optimum time for changing the leds in time. one and five seconds is still a good option so if you could just add three seconds as an option it would be awesome. When you have time of course no rush :) (if you even want to do it that is haha). Btw i deleted a lot of posts that won't help future people as i kind of spammed here whilst being a noob :).

[robkirk]

just to confirm jtag refers to the jtagen setting

[robkirk]

i was just looking at different leds and found a type called straw hat leds that spread the light evenly like a lightbulb instead of in a beam, wish i had known of these before i might even redo them with this type in the future when i get bored as my less are very close to the acrylic and you can see the brightness in the middle even with them lightly sanded :)

http://electronics.stackexchange.com/questions/2089/what-is-the-advantage-of-a-straw-hat-led

[gweeds]

yes they use them for LED christmas and party lighting. you might end up with a darker circle in the middle, as in the opposite of what you have now.

[robkirk]

tweeds just a thought but how hard would it be to incorporate a dimming feature either automatic or manual?

[robkirk]

I've gone for just diffused standard leds this time, see how they work out i shouldn't have to sand them and they are not high intensity so shouldn't be to bright i hope they are bright enough though. oh and i fixed the 3 dim orange less it was either a solder issue or faulty leds as i replaced them and seems fine now.

[gweeds]

Hmm yes I did see that, and no sorry mine doesn't do that, I wouldn't have put up with it. I would check your wiring and soldering, it could be the smallest of solder bridges that can cause that sort of effect.

[robkirk]

Added a few finishing touches today which included blu tak (a form of putty/plasticine) around all the inside grid rows to stop light leakage. Very pleasing to see the squares so crisp now. Also painted the grid black so you can't see it under the smoked acrylic. Added some push buttons on the back by drilling the back piece of acrylic and securing them with lock nuts then soldered onto the main board (my vero board is a mess with jumper wires everywhere and no doubt cold solder joints everywhere and it was 3rd time lucky as I'm no good at soldering). Officially finished and very pleased with it.

[robkirk]

oh and i used white baking paper to diffuse in place of the thick tracing paper gweeds suggested and it works very well.