Difference between revisions of "Arcane mixing techniques"

Revision as of 12:10, 31 August 2015

Digital techniques basics

For conceptual basics from the atomic level up see Semiconductors, Diodes and Transistors https://www.youtube.com/watch?v=wPHG0DCWcC0 AND An Introduction to Logic Gates https://www.youtube.com/watch?t=10&v=95kv5BF2Z9E.

Gates

AND

The AND gate behaves in the same way as the logical and operator: Output is true when both inputs are true and any otherwise false:

Input 1	Input 2	Output
0	0	0
0	1	0
1	0	0
1	1	1

OR

The OR gate behaves like a logical inclusive or: Output is true if either or both of the inputs are true and false if both inputs are false:

Input 1	Input 2	Output
0	0	0
0	1	1
1	0	1
1	1	1

XOR

The XOR (exclusive-OR) gate acts as a logical either/or: the output is true if the inputs are different, and false if the inputs are the same:

Input 1	Input 2	Output
0	0	0
0	1	1
1	0	1
1	1	0

NOT

A logical inverter, alias NOT gate, has only one input and reverses logic state:

Input 1	Output
0	1
1	0

NAND

A NAND gate works like an AND gate followed by a NOT gate:

Input 1	Input 2	Output
0	0	1
0	1	1
1	0	1
1	1	0

NOR

The NOR gate is a combination OR gate followed by an inverter:

Input 1	Input 2	Output
0	0	1
0	1	0
1	0	0
1	1	0

XNOR

XNOR (exclusive-NOR) gate is a combination of an XOR gate followed by an inverter:

Input 1	Input 2	Output
0	0	1
0	1	0
1	0	0
1	1	1

Universal gates

The NAND and the NOR gate can be considered to be "universal" because you can make any of the basic operations out of its combinations: an inverter, an OR gate or an AND gate. Non-inverting gates do not have this versatility since they can not make an invert.

Boolean algebra applied

Examples on the board

Serpent

Resources

Breadboards

You can buy solderless breadboards in a shop or online. Mind that you pick scalable like the SD-12 so you can hook up breadboards together and they become reuseful for other projects such as prototyping our own greenhouse sprinkler management systems.

Alternatively (and the path I will take), start gathering and collecting IDC ribbon connectors (Floppy drive cables, old HD cables, SCSI cables) to build your own breadboards with. To do this, you will also need a solder iron, hot glue, wire (for example telephone wire will do), a small screw driver, and a clamp. This board will also be scalable. Fine grained scalable. :D

Chips

TTL Logic

TTL (transistor-transistor-logic) chips were developed with use of transistor switches for logical operations and defines the binary values as:

0 V to 0.8 V = logic 0
2 V to 5 V = logic 1

They are inexpensive, but draw a lot of power and must be supplied with +5 volts. Individual gates may draw 3 to 4 mA. The low power Schottky versions of TTL chips draw only 20% of the power, but are more expensive. These chips have LS in the middle of their model number.

SN74LS00 (NAND) http://www.ti.com/product/sn74ls00

CMOS Logic

CMOS (complementary metal oxide semiconductor) chips are lower in power requirements (drawing about 1 mA) and operate with a wide range of supply voltages (typically 3 to 18 volts). The CMOS model number will have a C in the middle of it. A bigh drawback is extreme sensitivity to static electricity - they must be carefully protected from static discharges.

NMOS and PMOS Logic

PMOS and NMOS (p- and n-channel metal oxide semiconductors) offer the advantage of higher component density than TTL chips. They too are sensitive to damage from electrical discharge.

@@ Line 147: / Line 147: @@
 * 2 V to 5 V = logic 1
 They are inexpensive, but draw a lot of power and must be supplied with +5 volts. Individual gates may draw 3 to 4 mA. The low power Schottky versions of TTL chips draw only 20% of the power, but are more expensive. These chips have LS in the middle of their model number.
+* SN74LS00 (NAND) http://www.ti.com/product/sn74ls00
 ==== CMOS Logic ====