Search found 85 matches

by rstofer
Mon Jul 11, 2005 10:08 pm
Forum: General Discussion
Topic: Will assembler help me here?
Replies: 14
Views: 2615

Re: Will assembler help me here?

I guess one of the first questions is what to do if a second button is pressed while the first tone is still playing. Is it desired to abort the playback? Continue the playback for the first button but process the second button and ignore playback? Continue the playback for the first button, process...
by rstofer
Mon Jul 11, 2005 2:44 pm
Forum: General Discussion
Topic: Ideas For A Sensor
Replies: 31
Views: 6854

Re: Ideas For A Sensor

I think embedding anything or using any sensor that would limit the visibility through the layers would be a problem.<p>I was thinking about the scanner approach. Perhaps a 2 axis scanner that would go over the top of each layer in turn and sense the colored chips - perhaps in rows of four. If I cou...
by rstofer
Mon Jul 11, 2005 2:39 pm
Forum: Computer Programming
Topic: TTL output
Replies: 7
Views: 4454

Re: TTL output

The 8051 is the grandparent of all microcontrollers. There were a couple before it like the 8048 (?) but the 8051 is still in full use. There are hundreds of clones with enhanced gadgets. My personal favorite is the Philips 80C552. It has all the timers, PWM, USART, I2C, etc of the modern PIC but it...
by rstofer
Mon Jul 11, 2005 12:24 pm
Forum: Computer Programming
Topic: TTL output
Replies: 7
Views: 4454

Re: TTL output

This info is all over Google. The output stage of a TTL device has two transistors; one to pull up and the other to pull down. The logic ahead of the drivers insures that only one transistor is conducting.<p>You shouldn't have any problem interfacint low power Shottky to the 8051. Any of the 74LSxx ...
by rstofer
Mon Jul 11, 2005 8:23 am
Forum: General Discussion
Topic: Ideas For A Sensor
Replies: 31
Views: 6854

Re: Ideas For A Sensor

The MAVRIC controller adds 128K of RAM around the ATmega128 - see www.bdmicro.com. <p>I like the idea for teaching the controller. I means I may not have to try to compute the various aspect ratios.<p>As chips block the levels, I am not certain I will be able to see chips at lower levels, assuming s...
by rstofer
Sun Jul 10, 2005 10:09 pm
Forum: General Discussion
Topic: Mod-5 counter
Replies: 31
Views: 5575

Re: Mod-5 counter

On the off chance someone would want to build a modulo 5 synchronous counter with D flops, here it is.<p>Flop B (see previous post re JK flops for transition table) will transition to '1' when B=0 and D=0. So the D input will be the output of a NOR gate with B' and D' as inputs.<p>Flop C wants to tr...
by rstofer
Sun Jul 10, 2005 6:56 pm
Forum: General Discussion
Topic: Ideas For A Sensor
Replies: 31
Views: 6854

Re: Ideas For A Sensor

It's a real, physical game usually played with 2 players. The gameboard consists of 4 levels about 6" sqaure, 2" apart. The upper 3 levels are transparent and the bottom level is solid brown. Each layer has an array of 4 by 4 squares.<p>The object is to place chips in such a way as to form 4 in a ro...
by rstofer
Sat Jul 09, 2005 4:15 am
Forum: General Discussion
Topic: Ideas For A Sensor
Replies: 31
Views: 6854

Re: Ideas For A Sensor

Yea, I know! It's 4 AM and Norton Ghost just started doing an incremental backup.<p>While the chips probably couldn't be magnetic, they could be steel and detected by some kind of metal detector. Only the player's chips would be detected.<p>They could be pennies and detected by continutity via a pro...
by rstofer
Sat Jul 09, 2005 3:35 am
Forum: General Discussion
Topic: Ideas For A Sensor
Replies: 31
Views: 6854

Re: Ideas For A Sensor

The top three layers are transparent so that patterns through the levels can be observed by the player. Physical objects that obstruct that view are not workable.<p>The following assumptions can be made: First, all levels are clear when the game begins. Second, the computer know where it has moved a...
by rstofer
Sat Jul 09, 2005 1:52 am
Forum: General Discussion
Topic: Ideas For A Sensor
Replies: 31
Views: 6854

Ideas For A Sensor

Suppose I decide to implement the 3D TicTacToe (Cubic) game with a 3 axis arm and stepper motors. Most of you have probably seen the game; it is 4 levels of 4x4 grids (the top 3 are transparent) and each player uses colored chips and attempts to be the first to get 4 in a row.<p>I can build the arm ...
by rstofer
Fri Jul 08, 2005 5:52 pm
Forum: General Discussion
Topic: Mod-5 counter
Replies: 31
Views: 5575

Re: Mod-5 counter

Well, you will have to provide your own spacing for the table.
by rstofer
Fri Jul 08, 2005 5:51 pm
Forum: General Discussion
Topic: Mod-5 counter
Replies: 31
Views: 5575

Re: Mod-5 counter

The only reason I do homework problems is nostalgia. Given that:<p>Present State..| Next State =========================== State..D..C..B....D..C..B --------------------------- 0........0..0..0....0..0..1 1........0..0..1....0..1..0 2........0..1..0....0..1..1 3........0..1..1....1..0..0 4........1....
by rstofer
Tue Jul 05, 2005 6:36 pm
Forum: General Discussion
Topic: wye/delta
Replies: 3
Views: 1170

Re: wye/delta

Wye-delta starting is used to limit inrush current to 33% of nominal full load current. Torque is similarly limited.<p>See: http://ecatalog.squared.com/catalog/173/html/sections/14/17314041.html <p>If you chase the wiring through the two contactors to the 6 leads on the motor you will see how the co...
by rstofer
Sun Jul 03, 2005 1:54 pm
Forum: General Discussion
Topic: "universal" remote USB device IC ?
Replies: 2
Views: 921

Re: "universal" remote USB device IC ?

Personally, I would use serial IO. First because I could debug it using a real serial port or a USB serial cable.<p>If I just wanted to add that same capability to a project, I would look at http://www.ftdichip.com/FTProducts.htm <p>Parallax carries these chips, as well. The chips use a virtual comm...
by rstofer
Sat Jul 02, 2005 12:54 pm
Forum: General Discussion
Topic: 556 timer triggering problem
Replies: 30
Views: 5904

Re: 556 timer triggering problem

That 470k is definitely wrong! I didn't even look at that part.<p>You can disconnect Q3 from R5 and then connect R5 to +5V to see if the rest of the circuit functions. There's certainly nothing wrong with pulling Q3 base to ground with another 10k resistor. It will guarantee turn-off, assuming the o...