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I made a light that shines when the International Space Station is in the sky. I'm raising money to make a whole bunch and sell them.
I made a light that shines when the International Space Station is in the sky. I'm raising money to make a whole bunch and sell them.
292 backers pledged $18,637 to help bring this project to life.

Parts List

I'm working on the first revision of the board now. Over the last few months I've slowly learned how to engineer a proper electrical design from scratch. Now I've got a design to start with and suppliers picked out for almost every piece. To review the major parts of the board:

The Microcontroller

The brains. Same kind of chip as used in Arduinos(TM), and hopefully the finished board will be compatible for easy hacking (I have a little more research to do on that front).  Besides the chip itself, there are decoupling capacitors, a pull down resistor for one of the special pins, a crystal to run it at certain frequency, and a header to program the board with.

The Clock

In order to keep proper time I need another chip called a real time clock (RTC). This needs it's own battery backup, some more capacitors, it's own crystal for timing, and a current limiting resistor and diode on the battery connection.

The Display

The meat of the projects. 12 multi (red, green, blue) color LEDs  adding up to 36 total! Plus 3 driver chips to run each set of colors. More resistors and caps to control the current and smooth the power supply to each one.

USB

There is also a USB connector for power and the ability to update the pass estimations from a computer connected to the internet. It needs the physical connector plus required resistors on the data lines.

The Power Supply

The part I struggled with the most. There is a super efficient switching power supply that comes in a chip but needs an inductor and capacitors to match the voltages and switching frequency.

I really wanted something better than AA batteries, and so I added a Lithium polymer charging chip, which was surprisingly not as hard to do as I thought. (I also had help picking one out). That has it's own set of set resistors and a temperature sensor to make sure it doesn't overheat the battery during recharge. Then there is the battery sensing circuit described last week with the MOSFETs and the resistors.


And that's it! I think. Here is the combined bill of materials with part numbers. The only thing missing are some resistor values that I'll have to figure out empirical once I have the first one built -- specifically balancing the brightness of each LED color channel to get the best combination of look and power efficiency.

Next Week: Board Layout Version 1

  • Image 87455 original

Comments

    1. Creator Nathan Bergey on January 28, 2012

      @Doug I wrote the BOM in HTML, it's bundled with the other source files for the hardware. I posed a screenshot of it here. I'll add it to the documentation on open-notify.org as well when I get the chance.

    2. Creator Doug Keenan on January 28, 2012

      Good work - is that output just an image, not some sort of spreadsheet?

    3. Creator Reed Martin on January 24, 2012

      Sweet update! Watching this come together is flat out cool!

    4. Creator Mark Mitchell on January 24, 2012

      Sounds great! Nice work!

    5. Creator Mitch Dye on January 24, 2012

      Thanks for the update, Nathan! Very nice work. I appreciate the frequent and informative communications, man. Can't wait to get the kit & show it off to my other inventor friends!
      Cheers!

    6. Creator Cindy Bortel on January 23, 2012

      Great updates. I have been watching the ISS since the beginning, so your invention will enhance my opportunities here in the PNW. I come from a family of inventors and innovators, and to see your progress is inspiring. Isn't Kickstarter fantastic!!!!!!

    7. Creator Jeremy Southard on January 23, 2012

      Awesome! The Arduino is a wonderful thing! :-D Glad to see someone taking it from prototype to product using the ATMega328!

    8. Creator Nathan Bergey on January 23, 2012

      @Jeremy absolutely! I'll post all the code for the device once it's finished.

    9. Creator Jeremy Southard on January 23, 2012

      Thanks for the fantastic update! Any chance you'll release the Arduino code once it's all said and done?