|   Homemade digital light system. Teaser pics. | Fast Eddy
Dec 7, 2001 3:19 PM | | I took these for the report I'm writing. I'll send more detail when it's working if anyone's interested. Bet you didn't know that Niterider has a patent on water-bottle batteries...
I better get a f!@#ing 'A' for this. I am missing out on some epic riding weather around here.
Battery and Main Board.
A closeup of the main board. 28 pin PIC 16f876 on the left with the lcd connector along the front, 32k non-volatile storage center top. Two of the resistors near the PIC are a voltage divider so I can measure the battery voltage with the internal a/d converter. The two FETs drive the two light outputs.
Did I ever mention that I wear glasses, and I enjoy Star Trek?
Main Board, wiring side.
The goods. 4500mah Nickel Metal baby! |
| Sweet - Now if you layed out your own PCB and used... | Biking Viking
Dec 7, 2001 3:26 PM | | ...surface-mount components - this would be 1/5th of the size.
I used to work for the company that makes your EEPROM. Have you checked out Atmel's AVR micros, they all have EEPROM on-chip - and run circles around the PIC. I know, because I was on the team that architected the core and some of the peripherals...
BV |
| PIC has onboard EEPROM too.. | Fast Eddy
Dec 7, 2001 3:38 PM | | ...but not 32kbytes. I checked out AVR, but tools are not as plentiful. The 20mhz pic is already faster than I need.
I have $0.89 invested in my entire toolchain, and that is only because I wanted to use the same cable for my development board that came with my digital camera, and is already on my desk. I bought the female end for it at Radio Shack, et voila.
All the other tools, including the serial bootloader came from the web. |
| Hey man, nice job... | B Ziel
Dec 8, 2001 7:38 AM | | you might remember that I also built a light system a while back.
A couple of questions for you on the batteries - who makes 'em and where can I find 'em? Highest rated version I've seen in the AA size is 2200mah.
Thanks,
BZ |
| AAs? I wish. | Fast Eddy
Dec 8, 2001 2:02 PM | | They're 4/3 A size. Same proportions as AAs but 30% bigger. AAs are 14x50, these are 18x67(mm). These are the most storage I've found per size and weight. The pack of 11 weighs 24oz. $6 each at www.batterystation.com.
Where do you get 2.2ah AAs? |
| They are available... | B Ziel
Dec 8, 2001 5:26 PM | | through a relative who works for Exide Batteries. They are MiMH's made by Sanyo and are apparently for use in blasting (explosives) controllers. They are steep $$$...like $10 each....but here's the real "rub" - they are only guaranteed for 50 charge cycles. After that, they just fizzle out.
Actually, during my recoup time since August, I rebuilt my system and made a new battery pack using 18 Rayovac NiMH 1600mAh 1.2v AA's. (Part NM#715).
To solve voltage and run time issues, I took your advice from a few months back and hooked up with a lightbrain.com digital controller. That's a slick little unit. Thanks for that lead.
BZ |
| Let us know what grade you get. | Tiny Tank
Dec 9, 2001 6:12 PM | | I wear glasses and I enjoy Star Trek too. I also know of a few others on this board who do so. Welcome to the MTB Geek Club.. if I may call it this way.
Annie<--maybe will go back to school some day |
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