Designing a Multi Node LED PWM Lamp

Step 6 Summary

It truly amazes me that each lamp has 2 MIPS of horsepower in a SOIC-8 for 80 cents. As a string of lamps gets extended by adding more lamps the amount of MIPS on the string also goes up. In other words this is a scalable design. A string of 16 lamps is humming along with 32 MIPS of processing power. Just amazing.

There is still a lot of work yet to be done.

The development board needs to be updated. There are a couple of layout bugs that need correcting. The comm error output wiring does not seem to work with the transistor output. Not yet sure why - I have not spent any time sorting this out yet. The receiving communication code needs a bit more work too. By watching the LEDs I can see there are comm errors every so often. It appears there is an average of one random error per 1000 messages.

I need to find an SMD manufacture who would be willing to make lamp boards for me. Maybe Spark Fun would be interested? I have a buddy in Hong Kong that might be able to find me a manufacture. Board assembly must be automated. It is just not feasible to build these boards by hand like I did.

A PC interface board needs to be developed. This should be really easy - it is just a matter of taking the time to getting it done.

Cost is king - a minimized lamp cost (80 cents for the micro + three LEDs at 10 cents each + board / resistors / 20 cent diode bridge) a total of maybe $1.50 bucks. Add assembly, wiring, and profit and we're talking $2.00 to $2.50 per lamp. Will geeks pay $40 bucks for a string of 16 RGB lamps on a string?

Bottom line, I hope there is interest from the DIY crowd. With some positive feedback I will continue to pursue turning this idea into a product. I could envision selling the chips, lamp dev boards, and complete light strings. Given me some feedback and let me know what you think.

For more information and continued development news visit my web site at http://www.powerhouse-electronics.com

Thanks,
Jim Kemp

Comments

[Tgwizman]

I Really Like The Idea!

I was wondering if you could create one that had spot to plug it into your pc, then when someone bought it, they could program what lights lit up when and where they wanted to. You should also create a program in visual basic to go along with this.

After all said and done, this "Programmable Light Strip" could be used for a lot of things. It would also bring in the cash!!! A strip of 50 lights in a row with a control box on one end that had a "stow away usb" computer plug-in is something I would pay big bucks for! (Along with a cd of the program...) If you started mass producing these, you could sell them for around fifty us dollars each!

[jimk3038]

Tgwizman,

Thanks for the comments.

Your timing is perfect – I just completed a new Visual Basic application and posted it on my web site. The VB app uses a PC interface to connect to a string of lamps. It's kinda of test / demo app just to checkout the LEDs. It's all open-source so folks can adapt it to whatever they want.

Also, have a look at this instructable:
http://www.instructables.com/id/Kemper-LEDs-on-Vixen-Music/

This instructable shows what can be done with a bunch of KemperLED lamps connected to a PC.

I've started selling some KemperLED lamps and PC interface boards on my web site. You can find that all here on this site: ph-elec.com

Oh – and there is more, here is yet another instructable that shows what can be done with a single KemperLED lamp that is reprogrammed with custom firmware (note, the firmware is all open-source too): http://www.instructables.com/id/Pinewood-Derby-Car-with-LEDs-and-Jimmy-Neutron/

Lastly, just to get your juice's really flowing, I started work on a giant 7 segment display. My plan is to put one KemperLED in each segment. With a single comm link to a PC I can control each digit being displayed. So, seven KemperLEDs for each digit.

I thought it would be cool to build a scoreboard for my son's soccer games (he is only eight years old). I think I need nine digits to display the time, home team's score, away team's score, and the period.

The scoreboard, of coarse, can display digits in red, green, blue, or white. So I can flash red / green digits when the score changes, as an example.

So much to do and so little little time!

Thanks again for the comments,
Jim

PS: Don't forget to visit me on my web site: http://ph-elec.com/

[huntblack]

I will pay for this how much ?

[jimk3038]

Looks like about $2.50 for each lamp. Might be able to get the cost down to under $2 bucks if cheaper LEDs are used. Right now I'm working on the next version. The next version will be a simplified version. The new version (to get cost down) will use four wires. Also, the LEDs will be low cost 20mA type so that no transistors are needed. I expect the new (simplified) version to be ready in about a month. My plan is to build a 100 lamps for a real good test. I'll make a new YouTube video with the lamps on a XMas tree to get folks excited. I just can't wait to create a pattern of lights that look like falling snow! Don't worry, I'll make a new intructable specific for the new simplified lamps. Christmas is coming so quickly, Jim

[techgeek13]

Did you ever make that youtube video? I would like to see the simple version.

[jimk3038]

I'm still working in that direction. I've been working on this stufffull time for weeks.

I'll give you a sneak peek - have a look at the pictures below.

I started off thinking I would decorate a little Xmas tree with lights.That lead to the idea of a stand alone little tree. I actual made onefrom twisted copper. My son called it a "dead" tree and itlook terrible! Next idea was to build a flower / branch and stick theminto a vase. That's what are in the pics below. It still looks kind ofterrible (until the lights come on).

Right now, I'm working on one more bug in the software. Once I lick thatI promise I'll make a cool video to show. I know Christmas is coming quick.

It really is awesome when it is all lit up,
Jim

[techgeek13]

Thanks, I really appreciate it.