Testing SoftwareSerial library in the Trinket to drive the 7-Segment Serial Display COM-11441 (Sparkfun)
The potentiometer value was maped in the range 900 to 2100 microseconds to generate the servo control pulses.
The Serial Display shows the pulse duration in milliseconds.
Using bit banging instead of SoftwareSerial saves more than 2K of program memory.
The YouTube video:
Arduining 
Where is the code?