Last August I finished assembling a 3d printer that I had in the works for over a year. The printer from now on will be referred to as The Mandelbot! I will blog on the topic of said printer in the future. As for today’s post the Mandelbot needed a light to illuminate the build area. I looked around on the web for some kind of pre-built solution, but I had some criteria that had to be met. I wanted it to fit in a certain location on the machine so that quickly narrowed down the options I had. I definitely wanted it to be rgb led, I mean its got to change colors. I thought using one of the neo pixel rings Adafruit sells might do nicely but due to size constraints no dice! So I figured it was a good excuse for me to have some pcb’s made up. I tend to always machine, or etch my own pcb’s. I do this because it’s fun and I want it now, or in the time it takes me to make it. But this one was special. I wanted the end product to be awesome, easier to solder (smd stuff), and look great. Even though once its on the machine you really wont be able to see it unless you look up from underneath.
I had some ideas for how I wanted the light to work with the printer. I thought it would be great if I could control the light via the printer interface with mcode’s. The downfall there is I would have to change the firmware to recognize those codes, which would be fine except that the firmware is still being upgraded all the time, and I’ve been keeping up with the latest build. I use a Smoothieboard for the Gcode interpreter on the Mandelbot, and I am pretty sure the developers of Smoothie are not going to want to include some code for a machine no one else has. So that means the light has to have some sort of controller IC. In comes the MSP430. Since I was going to have rgb leds on the board I decided to go with the WS2812 rgb led. To control the leds I am using a MSP430G2452. There are a couple of voltage regulators on there to handle the power needs, because I am running this off the 12v 15amp supply for the machine, one is a TI LP2989 5v 500ma LDO for the leds, and the other is a TPS70936 3.6v 150ma LDO for the MSp430. There’s also a button for cycling through the colors. I’ve been curious about these leds for awhile so I figured this was as good of an excuse as any to mess with them.
Here’s the schematic:
After I checked, re-checked, and triple checked, I sent it in to OSH Park. I know I could have more made for cheaper if I would have used any one of a number of off shore manufacturers but I only needed 2 and the OSH park boards looked great. I have to say the OSH Park web site is painless to use and the quality is great!
Here is what I ended up with:
Now to get busy.
Here’s the power rail all soldered up and working, well the led is.
I am definitely happy with the way they turned out. Now to dial in the code and mount it on the machine. I will post when I get that done.