RGB LED Ring

The next round in my prototyping game. I declare this board as the final version, more or less ;-) Design files, code and documentation .

The next round in my prototyping game. I declare this board as the final version, more or less ;-) The TS2940CW 5V voltage regulator is truly a masterpiece of engineering. It uses a PNP transistor as the output stage and therefore the voltage drop is more or less only based on its V(CE)-sat voltage. The maximum drop is 0.6V at about 1A. This board only needs about 100mA max. and therefore you can safely ignore the regulator's voltage drop. If you feed the board with 4.0V, the cpu will get about 3.95V - very nice! You can use the onboard regulator to feed power to other parts of your project as well. I'm thinking about adding this one to my collection of purchasable DIY KITs on my blog. But right now I'm out of LEDs and haven't found a cheaper source for them that I like. I haven't used alibaba/aliexpress yet, so I feel a bit uneasy with ordering in the 1k pcs range directly from china. Ebay is not a good source for high volume orders it seems. Still too expensive per single RGB LED. It reliably runs with 4V to 14V. The voltage regulator could take more, but the tantalum capacitors max out at 16V. Although less energy efficient, it can now be easily used with a 9V block or several AA batteries and doesn't require a somewhat costly boost converter anymore. Click here here to see the front side. Design files, code and documentation .

The next round in my prototyping game. I declare this board as the final version.

The next round in my prototyping game. I declare this board as the final version.

All of it. This is revision 1.21 It is now equipped with an optional (jumper) ultra low drop voltage regulator and can run from either regulated 5V DC or from up to 14V DC (no spikes please). The input voltage is limited by the regulator's decoupling caps. I could only get 16V tantalum types in 1206. It also now supports auto-reset for even easier code updating. With the onboard regulator it can conveniently be powered by say a 9V block or 4 AA batteries.

Top side. This is revision 1.21 It is now equipped with an optional (jumper) ultra low drop voltage regulator and can run from either regulated 5V DC or from up to 14V DC (no spikes please). The input voltage is limited by the regulator's decoupling caps. I could only get 16V tantalum types in 1206. It also now supports auto-reset for even easier code updating. With the onboard regulator it can conveniently be powered by say a 9V block or 4 AA batteries.

Bottom side. This is revision 1.21 It is now equipped with an optional (jumper) ultra low drop voltage regulator and can run from either regulated 5V DC or from up to 14V DC (no spikes please). The input voltage is limited by the regulator's decoupling caps. I could only get 16V tantalum types in 1206. It also now supports auto-reset for even easier code updating. With the onboard regulator it can conveniently be powered by say a 9V block or 4 AA batteries.

I finally got the PCBs from sparfun. It almost took 6 weeks. 9 days for the letter to get to me. I wonder what takes so much time for "air mail". Must have been my "dear friends" at the customs office again. Unfortunately this is _not_ the updated design I sent them shortly after I had placed my order, so this PCB version doesn't support auto-reset :-( Let's hope the rest works.

I finally got the PCBs from sparfun. It almost took 6 weeks. 9 days for the letter to get to me. I wonder what takes so much time for "air mail". Must have been my "dear friends" at the customs office again. Unfortunately this is _not_ the updated design I sent them shortly after I had placed my order, so this PCB version doesn't support auto-reset :-( Let's hope the rest works.

I finally got the PCBs from sparfun. It almost took 6 weeks. 9 days for the letter to get to me. I wonder what takes so much time for "air mail". Must have been my "dear friends" at the customs office again. Unfortunately this is _not_ the updated design I sent them shortly after I had placed my order, so this PCB version doesn't support auto-reset :-( Let's hope the rest works.

I finally got the PCBs from sparfun. It almost took 6 weeks. 9 days for the letter to get to me. I wonder what takes so much time for "air mail". Must have been my "dear friends" at the customs office again. Unfortunately this is _not_ the updated design I sent them shortly after I had placed my order, so this PCB version doesn't support auto-reset :-( Let's hope the rest works.

I finally got the PCBs from sparfun. It almost took 6 weeks. 9 days for the letter to get to me. I wonder what takes so much time for "air mail". Must have been my "dear friends" at the customs office again. Unfortunately this is _not_ the updated design I sent them shortly after I had placed my order, so this PCB version doesn't support auto-reset :-( Let's hope the rest works.

I finally got the PCBs from sparfun. It almost took 6 weeks. 9 days for the letter to get to me. I wonder what takes so much time for "air mail". Must have been my "dear friends" at the customs office again. Unfortunately this is _not_ the updated design I sent them shortly after I had placed my order, so this PCB version doesn't support auto-reset :-( Let's hope the rest works.

I finally got the PCBs from sparfun. It almost took 6 weeks. 9 days for the letter to get to me. I wonder what takes so much time for "air mail". Must have been my "dear friends" at the customs office again. Unfortunately this is _not_ the updated design I sent them shortly after I had placed my order, so this PCB version doesn't support auto-reset :-( Let's hope the rest works. Edit: Works great and will go on my BIKE! 100% illegal taillights ;-)

No test drive yet. It has snowed a lot and it feels like -20°C outside. My fingers almost fell off.

2x RGB LED Ring , 2x AA, 1x MAX756, 1x 1N5817, 1x 22µH 3A, 1x 220µF, 2x 47µF, 1x 100nF and lots of patience. No test drive yet. It has snowed a lot and it feels like -20°C outside. My fingers almost fell off. And the best thing, as usual, it works with the Arduino IDE. Just pull off the cpu modules and reprogram them as you like. A 6pin FTDI compatible header is on their backsides. There's also an ICSP header, but that can only be used once to program a bootloader. After that MOSI/MISO/SCK are used for the LEDs (whole PORTB of the chip). The backplane provides power (5V) and a common bus consisting of 2 GPIO pins and of course the I2C lines. In this case I use one line for a trivial syncing routine. The boards run with the internal oscillator and that seems to vary quite a low between these two chips. Without syncing after each run, there would be significant dephasing. Now I should really get some mudguards. Getting a wet but is one thing, but deliberately exposing hand-made electronics to a mixture of salty, dirty and half molten snow is unheard of.