From: Winfield Hill
Subject: Re: Roulette Wheel Project
Date: 27 Dec 2002 12:47:28 -0800
Organization: Rowland Institute
X-Newsreader: Direct Read News 4.20
Gary Lecomte email@example.com wrote...
>>> Here is another good project for those who are interested.
>>> The article is not totally complete yet as I have to reconstruct
>>> the documentation. But there are some pictures of my unit that
>>> I made about 25 years ago. The Schematic and PCB are also there.
>>> Not sure if the schematic is error free, but the PCB has been
>>> checked over carefully. In the Projects area at:
>>> Season Greetings to All of you!
> As to these chips, they not obsloute yet and are all still quite
> readily available! My supplier has no problem getting them!
I agree, the 4000 series chips are easy to get and will probably
stay that way for some time to come. It was fun designing stuff
with them in the old days... But these days everything's either
in a microprocessor, a CPLD or a FPGA, if not a custom VLSI.
> So, Since your into the digital stuff, lets see your design with
> this cheap Microcontroller!
OK, Gary here's my entry. 28LEDs, a PIC processor, four 2n7000
FETs, two resistors and a pushbutton. Oh, plus a program. :>)
. SPIN pullup ______________
. _|_ | | |
. gnd ---o o---+----| input |
. | |
. 4 | one of four |
. ,-,-,=,================/===| outputs |
. | | | | one of | is HI |
. etc | seven sets | |
. to FET | ,--------|>|--, | |
. gates __| | ,------|>|--+ | |
. ____| |__| | ,----|>|--+ | |
. | ___ | | | ,--|>|--+---| \ |
. |___| |___|_| | | --| | |
. | ___ | | | | six --| | one of |
. |__| |____|_|_| | more --| | seven |
. | ___ | | | | places --| | outputs |
. |_| |_____|_|_|_| --| | is LOW |
. | | | | | \ --| / |
. R - etc - \ |______________|
. current-limit \
. resistor to +5V bank of 4x7 = 28 LEDs
With the SPIN button depressed, the program ramps up the speed
of the ball, keeps it going after the SPIN button is released,
then slowly lowers the spin speed to zero, thus revealing the