T&L Publications

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...

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...

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...

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 ...

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...

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...

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...

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...

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...

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 ...

Well, you will have to provide your own spacing for the table.

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....

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...

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...

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...