void setup() {
  // put your setup code here, to run once:

}
void loop(){
  ;
}
Digital InputBreakout
xr0.0
xr0.1
xj0.0
xj0.1
Truth Table
-------------
B1 B0 A1 A0 | C3 C2 C1 C0 | Decimal
----------------------------------------
0 0 0 0 | 0 0 0 0 | 0
0 0 0 1 | 0 0 0 0 | 0
0 0 1 0 | 0 0 0 0 | 0
0 0 1 1 | 0 0 0 0 | 0
0 1 0 0 | 0 0 0 0 | 0
0 1 0 1 | 0 0 0 1 | +1
0 1 1 0 | 1 1 1 0 | -2
0 1 1 1 | 1 1 1 1 | -1
1 0 0 0 | 0 0 0 0 | 0
1 0 0 1 | 1 1 1 0 | -2
1 0 1 0 | 0 1 0 0 | +4
1 0 1 1 | 0 0 1 0 | +2
1 1 0 0 | 0 0 0 0 | 0
1 1 0 1 | 1 1 1 1 | -1
1 1 1 0 | 0 0 1 0 | +2
1 1 1 1 | 0 0 0 1 | +1
0 | 1
C0
C1
C2
C3
A0
A1
B1
B0
Two's Complement
---------------------
Decimal | 2-bit Binary
-2 | 1 0
-1 | 1 1
0 | 0 0
1 | 0 1
xr1.0
xr1.1
xj1.0
xj1.1
xr,jn.b
--------
xj0.0 + xj1.0
xr0.0 + xr1.0
C2
C3
C2
C3
xj0.0 - xj1.0
xr0.0 - xr1.0
xr0.1 + xr1.1 + C
xj0.1 + xj1.1
xr0.1 - xr1.1
xj0.1 - xj1.1
Digital OutputBreakout