Ornament Soldering Kit - 2019

By Jamal Bouajjaj

Introduction:

This project is a PCB soldering kit in the shape of an ornament, designed to be hung on a Christmas tree. The kit has been designed with some SMD and THT parts. If you plan to use this design as a kit for people who have no/minimal soldering experience, it is recommended to pre-solder the SMD parts before giving the board to them for them to solder.

Warnings/Issues:

Due to the original intent of this kit, it will have many reference to the University of New Haven and it's makerspace.
If you plan to use this kit for your own purpose, it is recommeded to update the PCB in Kicad to remove such marks. The same applies for all CAD drawings made in Autodesk Inventor 2018.

Note:

D1-D6 are connected together, and D7-D12 are seperatly connected together. This allows, thru the 2 jumpers on board, to either make D7-D12 blink with D1-D6 or inverse them.
Just make sure that you don't modify the jumpers in a way that will cause the 555 or power to short out. See schematic for details.

Project's folder:

Click the GitHub folder below to access the project's files, which include the KiCad PCB files, the Gerber files, and the Autodesk Inventor CAD files.

Pictures:

Comming Soon!

PCB Parts:

This kit has some THT and SMD parts to be soldered (THT means through-hole, and SMD means surface-mount).

PCB Reference	Part Description	Package Size	Quantity per Board
F1	250mA Polyfuse	THT	1
C2	1uF Decoupling Capacitor	SMD-1206	1
J1	5-9V Battery	THT	1
U1	555 Timer	DIP-8	1
R13	4.7kΩ Resistor	THT	1
C1	100uF Capacitor	THT	1
D1-D12	5mm LED	THT	12
R1-R12	330Ω Resistor	SMD-1206	12

Theory of Operation:

The circuit is based on the 555 timer. The chip, if set up as done in this circuit, will act as an oscillator which will generate a square wave on the output where the frequency is dependent on R1, R2, and C1. With the chosen values, the output will have a frequency of 1.2Hz(the output will oscillate once every ~0.85 seconds). This output is used to drive 6 LEDs when the output is a LOW. The other 6 LEDs are set to be on when the output of the 555 is a HIGH, but this can be changed with the 2 available jumpers (WARNING: If changed the jumper incorectly, you can possible short out either the 555 or the power supply. If you want to change the other 6 LEDs so they blink with the first 6, cut the short in the jumper on the PCB with a knife, then solder the middle pad to the pad that wasn't previously connected(refer to schematic for details))

Schematic:

Here is the PCB's schematic:

Technical Diagrams:

Here is some diagrams relating to the project:

Case:

The PCB is designed to be screwed into a bettery holder and to be hung on a Christmas Tree. The STEP and STL files for the battery holder for the ornament can be found in the GitHub page.