This is a simple Chrismas tree project inspired by bluqesh. I've updated its design adding slots for board to board connection and addressable RGB leds.
At that point I've also switched the MCU to an ESP8266 to add WiFi capability, and using the amazing WLED project to control everything.
Project files are available in the Project Outputs for xMas-Tree directory.
In the 3DModel folder there is the 3D model and the "textures", and some photos.
- USB C Compatible, it negotiate 5V@900mA
- IR Remote receiver
- WiFI controllable
- Full PCB is 10cm x 10cm so it fit the 2$ JLCPCB option.
- Most of the components are available from LCSC.*
- Different patterns and animations
- More info on WLED project
*The ESP8266-12 and the LEDs have to be bought separately
While placing the 0603 components is not that hard if you have SMD skills soldering the LEDs is quite difficult! Mostly due to the VIAs to give the pads more rigidity. I'm still experimenting a way to easily solder the LEDs, probably using a stencil and low temp solder with hot air is the best solution.
Right now I'm soldering the second tree.
For now my assembly procedure (without hot plate soldering and solder paste) is:
- Solder all the
0603excpet the one near the USB C contacts. - Solder the USB C
- Solder the 5.1K resistor skipped on step 1.
- Solder the ICs.
- Solder the LEDs, make sure that they are firmly soldered.
- Solder the ESP module.
- Check for shorts and program the ESP. Test if first 6 leds are working.
- Snap the boards and solder them together
- Check again for shorts and enjoy!
Probably with hot air and a low melting point solder paste step 1-6 can be done in a single jump. Right now I only have flux, and 60/40 solder.
I managed to find a old solder paste, and yes, it makes the assemply a lot easier. I don't have a stencil and in anyu case soldering the LEDs would require manual reworks due to vias under the pads.
To solder the LEDS with this metod i proceed as:
- Fill the LED pads with the solder paste proceed with the reflow WITHOUT the LEDs.
- The solder would be wiked into the vias, apply again the solder paster and properly reflow the LEDs.
With my cheap hot air station I use 360°C to solder all the components and 220°C for the LEDs.
I'm a noob with LED soldering I've melted 8 of them on assempling 4 tree. So be careful. (Four on the first board, one fell on the fold and was lost. One had RED color not working. The others 2 has been melted on second and third board)
- The USB FUSE seems to be not working as expected, so a 0OHM link is required. (This seems to be a single case)
- The LEDS PADs have vias to give them more strength, but unfortunatly makes a lot harder to solder the LEDs
- Some 4.7uF caps (LEDs bypass seems to be not needed and some of those cant be soldered or the boards cannot be assempled in shape)
The touch button is connected to the BOOT0 pin, so you have to press that while you start the sketch upload process.
A FTDI 3.3V module with RESET is required, I didnt had one so I temporary connected a wire to ground while also pressing the TOUCH button.
The FW can be found under the WLED repository, I'm using a ESP12, so d1_mini is the right platform to choose.