Wheel encoder (print on transparency using a laser printer)
emoShield hardware and software
emoShield sample Arduino sketch — when using the emoShield without Lil’Bot
ExpressSCH (schematic capture) and ExpressPCB (printed circuit board layout) software
This is the easiest and most intuitive design package available, and it is free. ExpressPCB does not produce Gerber files for PCB manufacturing. Instead, you order your boards directly from expresspcb.com using the application. (We have no business ties with them other than ordering prototypes now and then.) Gerber files are available for an additional payment after your order has been placed.
Download the schematic and PCB design package here.