Expand the built-in Arduino functions ...

**Digital I/O**
```
digitalRead() 
digitalWrite() 
pinMode() 
```
**Math**
```
abs() 
constrain() 
map() 
max() 
min() 
pow() 
sq() 
sqrt() 
cos() 
sin() 
tan() 
random() 
```
**Advanced I/O**
```
noTone() 
tone() 
```

**Time**
```
delayMicroseconds() 
micros() 
```