Resources
Electronics
Don Klipstein’s LED Web Site: Tons of authoritative information about LED manufacturing, characteristics, etc.
Stepper / CNC Project
Allegro A3977, Idle noise Help: Discussion about PWM noise on steppers, advice on separate logic and power grounds
Tero’s Project Corner: Student-produced A3977 board (very attractive!)
PCB
Techwando on Gold Phoenix for small PCB orders
Drill Bit City: Resharpened PCB drill bits
PreciseBIT Scoring / Engraving Bits: Trace isolation milling bits
Drill bit size chart (Wikipedia)
Drill bit size chart (Drill Bit City)
Ethernet
Lantronix XPort: RJ-45-sized server
gridconnect: XPort retailer