POV Christmas Tree

Still don't have a tree for this holidays?, Don't worry here you have a small, reusable, eye-catching tree for your holiday needs.


This project started as a SMD soldering tutorial for a course i've made in electronics, so it's meant to be a one day project to learn a little bit of SMD soldering and also have the coolest of all trees.

Step 1: Gather the Materials

For making the Awesome POV tree you will need:

1x    PIC12F689 or 1x PIC12F675 (PDIP8)
1x    8 pins IC socket
1x    LM7805 5V voltage regulator
1x    0.1uF capacitor 50V (1206 SMD)
1x    10uF capacitor 16V (1206 SMD)
10x  220R resistors 1/4W (1206 SMD)
9x    220R resistors 1/10W (0603 SMD)
1x   10K resistor 1/10W (0603 SMD)
18x  Green leds  (0805 SMD)
10x  Blue leds (0805 SMD)
1x    White led (0805 SMD)
1x    Pushbutton (5mm height)
1x    9V Battery clip
1x    9V Battery
1x   15x8cm PCB board
1x   12cm brushless fan (also works with 8cm ones)

IF you build the optional speed controller:
1x  LM317
1x  220R resistor (1206 SMD)
1x  5K 1 turn potentiometer
1x 12VDC power supply or some more batteries
4   meters of small cable for the DC power line

All components are easy to source from any electronics dealer, in my case I just have all the stuff around in my room.


You will need some tools:

- Soldering iron (15-25W) fine tip
- 0,5mm rosin core solder (or anything you have in hand)
- Small wire cutter
- Fine tip tweezers
- Cardboard knife
- Metallic ruler or metallic frame
- Double sided tape or epoxy glue
- Magnifying Glasses or standalone magnifying glass


Also you will need a way to etch the PCB design.

Sorry, that info isn't the objective of this intructable, but follow this link for materials and method:
https://www.instructables.com/id/Sponge-Ferric-Chloride-Method-Etch-Circuit-Bo/step3/Etch-the-Board-Instant-Gratification/

Anyway my materials for etching are:
- Fine tip permanent marker pen
- Fine Steelwool
- Cheap magazine paper
- Ferric Chloride
- Small sponge
- Latex gloves
- Plastic Laminator (or iron)

And a way to program the microcontroller.
if you're building a programmer try the cheap and dirty "Pablin 2" with the Winpic800 software.
link: http://www.pablin.com.ar/electron/circuito/mc/ppp2/index.htm

If you want an usb programmer, bouy pickit 2 from microchip or build/buy a pickit2 clone
link: http://sergiols.blogspot.com/search/label/PICKit2Clone
link: http://www.microchipdirect.com/ProductSearch.aspx?Keywords=PG164120

Step 2: Etch the Board

Download the attached PCB file and print it so that the margins of the pcb are 15x8cm
Use "letter" for page size and you shouldn't have any problems.

I'll upload the schematic in a future update, but hey its christmas i'm supposed to be somewhere else helping for the meal.





There are a lot of different DIY techniques for etching at home, find the one that best suits you.

In my case I use the Toner Transfer on magazine paper with laminator / Ferric Chloride bath + sponge combo. (see images)

This is the cheaper / faster way to do it if you are making prototype PCBs more than 1 or 2 a month. For the occasional user try iron on transfer and sponge technique.

REMEMBER to use the darker mode on your printer and mirror the image for printing if you are using the transfer method.

(update 12/25/10: Fixed pullup and ground traces on the PCB please download 2.0 version)

Step 3: Cut and Drill the Holes

Cut the board in the pieces shown in the image.
Use a dremel disk or a filed back dent of a cardboard knife
The 5x2cm rectangular base is added in the final PCB drawing

Drill 1mm holes for the push button, the 5k pot and the wire bridges.
Also you can drill the TO220 regulators holes but is not necessary since we will surface mount them.

I use a "nail polisher" drill. No need for a fancy drill press or anything, the center hole on the etched copper pads will guide your drill bit straight down.

[Update 212/28/2010]: The attached file downloads as ".tmp".  Just rename the extension to .rar to open it (sorry not my fault, maybe is the new instructables flash ulploader)

Step 4: Solder the Pads, Then the Components

OK, now the SMD soldering tutorial part.

For soldering SMD components FIRST always use some magnifying lens of some kind.
You WILL be able to see the process witouth it but it will really make your eyes strain. Not good if you love your eyes auto focus features in long term.

The logic behind soldering SMD is that you first solder just one pad of the component, place the component and align it with this pin and then solder the rest.
Easy, but the probability of missing a solder pad in the process is big so use this simple rules:

- Always solder from the same side in my case the right.
- Turn the PCB so that your top pads are to the right
- Presolder all the top pads
- Place and align all your vertical components with their top pads
- Turn the PCB 90º to the left
- Presolder all the right pads
- Place and align all the horizontal components with their right pads
- Turn the PCB 90º to the left again
- Solder the bottom pads of your components
- Turn the PCB 90º to the left again
- Solder the left pads of your components
-Solder the first pin of any major component and align the rest (chips, transistors voltage regulators, witches)
-Solder the rest of the pins of the major components
-Solder wire bridges from the bottom side

You're done!

Always make sure with SMD to center the component to the pad.
Just look at the unsoldered pad when centering with the other one that it is in the middle of it.

One special note is with led polarity in SMD, usually they have a "T" mark on the bottom or dots on the top . The dots or the bottom part of the "T" indicates the cathode side "negative" (see the images for reference on the topic).
Cathodes are marked with a minus sign near the pad on the pcb

Another note is mounting though hole components like SMD. Just trim a little of the ic socket pins and solder from the side one corner pin first, align the rest and solder. For the TO220 regulators just bend the pins down, cut to size and solder, isolate the thermal pad from the board with some double sided tape.

Step 5: Program the Chip

Download the hex file and program the chip with the following config fuses:

__config _CP_OFF & _CPD_OFF & _BODEN_OFF & _MCLRE_OFF & _WDT_ON & _PWRTE_ON & _INTRC_OSC_NOCLKOUT

That's translated to:
h018C or
b110001100
on the config word

OK, 2.0 Firmware upgrade and fixed PCB uploaded, now it has 5 spinning modes and one stopped mode (default). Also fixed pushbutton ground and pullup trace (sorry small mistake on my part)

Step 6: Test the Board

Without the microcontroller, power up the board, you should see all leds light up. (Polarity (-)(+)6-12VDC see image)

The green ones alone at full brightness and the Green/Blue pairs at half or less brightness.

If your leds are not working check their polarity or any missing solder joints on the pads.

Step 7: Mount It to the Fan

Solder the PCB copper base to the tree.
Align it so that the tree is centered and at exactly 90º to the base (ruler and marking holes in the middle of the base helps here)

Then with hot glue gun, epoxy glue or double sided tape (preferred) fix the battery under the base

Later fix all the rig to the center point of the fan. To find it just grab a ruler and measure the diameter in horizontal and vertical, the biggest diameter is the center line in each direction, X marks the spot

Try powering the rig up and then start rising the voltage slowly on the fan.
If everything starts rumbling a lot, stop the fan and you need to balance the weight.
Try moving a little the mounting point on the fan and adjusting the 90º of the tree base.
Also you can add some weight to the sides with the PCB scraps to balance

Step 8: Show It to Your Friends

Hope you like it,

Use it as a table top decoration, a gift or for your office cubicle collection of toys





Happy holidays!

Comments

[dhopper122]

Suggestion: instead of etching away all of the copper and shortening the life span of your etching liquid, try outlining your traces just so the main lines are clear of the bulk of the copper you would have normally taken off. It will save you in the long run.

[thisoldgeek]

Great project El_AMPo! I just built one of these and it works well. Only thing is, the LEDs are too bright. I feel like I'm going to go blind watching it... I'm using a 9V battery like your instructable to power the tree itself. Is there any simple way to dim the LEDs? Could I lower the voltage somehow, put in a diode or a resistor?

Thanks again for the great work. My wife loves it!

[jlforma]

We are coming up to Christmas and enjoyed making this Christmas tree that taste very nice. Someone help me pose ... I can not download the file code "Tree + Firmware PCB 2.0.rar60 KB". Someone can help me. My email is: [e-mail]. Thank you.

[El_AMPo]

Muy bueno Andres
Felicitaciones
Lilian A.

[afwin]

nice idea
thanks

[punkzter]

Do you think that this project could use an attiny chip?

[El_AMPo]

Shure, but you would need to write the software

[punkzter]

What does the "PDIP8" mean? I went to microchip direct and want to buy the chip. Is the equivalent chip the "PIC12F675-I/P"?

Also, does microchipdirect program chips for you? Would this save me from having to purchase a programmer? Does anyone know?

Thanks.

[El_AMPo]

12F629 and 12F675 are pin compatible chips but the 1F675 has analog to digital converter that is not used for this aplication. PDIP8 means they are dual in line 8 pin through hole devices.
Microchip direct refuses to work for my country, but is a nice source, also they have free samples.
For the programming part sorry, the only way is to make a cheap programmer or find someone to program the chip

[punkzter]

When I go to MicroChip direct, they have so many different options for this chip:

http://www.microchipdirect.com/ProductDetails.aspx?Catalog=BuyMicrochip&Category=PIC12F675&mid=10&treeid=1

Could you help me with picking the correct one?

[papalevies]

Is there a way to connect the power cable to a battery outside the fan instead of on it? Some kind of mechanism that enables cables to not get twisted when passed through a rotating assembly such as this?

[El_AMPo]

Yes it's possible, search for "rotary contacts", but beats the simplicity of design and the objective of this circuit

[Greasetattoo]

Great instructable..
One question though..

What is POV?

[El_AMPo]

POV: Persistance of Vision
Is the analogous to your eyes "refresh rate", where the light dalays a little to go away, the camera flash persistance effect is a simple example of the effect.
Tube TVs and multiplexed led displays work this way.

[jomac_uk]

POV stands for Persistence Of Vision

Basically the eye is too slow to notice and capture fast moving things, the eye can be tricked into seeing a solid and continuous visual image, when in fact it is a high speed, set of dots or pixels that are moving too fast for the eye to capture.

[Greasetattoo]

Thanks, that is what I thought..

I used to work in a ray-traced program called POV.
http://www.povray.org/

Thanks for your answer!!!

[TOCO]

really cool. great ible!

[computer_guy]

AWESOME!!!
just too much work for me heheh...

[El_AMPo]

Took me one afternoon to complete it, if you have all the materials

[zack247]

and the skill :) (i dont)