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OpAmp
The output is a function of the difference of the inputs.
If ( noninverting(+) > inverting(-) )Vout swings to +V
If ( inverting(-) > noninverting(+) )Vout swings to -V
Small changes of Vinresult in large changes of Vout
OpAmp
Vout = Vin * Rf/Rin Output voltage is fed
back to inverting input.
Amplification (gain) can be controlled by varying Rf
Useful for amplifying weak signals
Comparator
A comparator is a type of OPAMP that is used for comparing 2 voltages.
Vref = reference voltage
Vin = voltage to be comparedNon-inverting
Inverting
Comparator Application
When Vin exceeds Vref of voltage divider, Vout of opamp will go high and turn on LED.
It's a 1-bit analog-digital converter!
connection no connection
componentdesignation& value
ground
power supply
component
pin #
signal nameor symbol
schematicsignal name
What does the “>” mean?
That input is edge-triggered not level-triggered(positive edge-triggered in fact, rising edge)
This >
Buses
A grouping of common signals. For examplem a Data Bus will contains
all 8 or 16 bit data lines (D0..D7 or D0..D15).
ASCII Art Schematic
+5 ---+---------------+---+| | |R +----------+|(see below) | 8 4 |
+---+------+-----|7 3|------/\/\/\---+------- Vout| | | LMC555 | |C to test +-----|6 | -----| | | -----
ground +-----|2 5|----+ || | 1 | | ground| +----------+ 0.1 uF| | |
Clock ----+ ground ground^
(Use a fixed-width font )
GPIO
General Purpose Input/Output Connections through which the
microcontroller can connect to external peripherals.
Over Simplified IO pin
V+1 0 1 0 1 0 1 0
External pin
Input Register
1 0 1 0 1 0 1 0
Output Register
InputOutput
Register
A small amount of very fast computer memory used to speed the execution of computer programs by providing quick access to commonly used values.
Hardware Debounce
Press button, discharge capacitor, release button to charge it.
Unfiltered button
Debounced button
Logic input Valid High
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