make these executable:  
   chmod +x pcb.py  
   chmod +x frep.py  

execute:  
   pcb.py | frep.py  

view:  
   out.png

optional arguments:  
   pcb.py | frep.py dpi  
   pcb.py | frep.py dpi filename  

dependencies:  
   Python  
   NumPy  
   Python Imaging Library  

samplea:
![](http://academy.cba.mit.edu/classes/embedded_programming/hello.arduino.328P.png)