Reprap StepStick

Overview

This is an Allegro A4983 / A4988 x4 breakout board for Sanguinololu. It can be snapped apart at the score in case of Allegro failure, and replaced with another or a Pololu. Snap all 4 apart and get a pin-compatible clones for use on boards like RAMPS or Gen7.

Now this is not for the iron wielding solderer. All parts are SMT, and somewhat small - there are some 0402 sized packages. Not to mention the Allegro's thermal pad - a solder pad on the bottom of the chip - can't be soldered without an iron of magic. Go shoppingReprap StepStick

Open Source Files

• Reference: http://reprap.org/wiki/StepStick

Gerber file

• Eagle files here: https://github.com/mosfet/StepStick
• How to Export Gerber files from Eagle

Schematic

BOM

Item	Package	Value	Value	Tolerance	Voltage	Position	Note
Capacitor	402	0.1uf		10%	16V	C1, C2, C5, C6	16V capacitor for 12V maximum voltage; use higher voltage capacitors for higher voltage applications, max 35V
Capacitor	402	0.22uf		10%	16V	C4, C7	16V capacitor for 12V maximum voltage; use higher voltage capacitors for higher voltage applications, max 35V
Capacitor	1206	4.7uf		10%	16V	C3	16V capacitor for 12V maximum voltage; use higher voltage capacitors for higher voltage applications, max 35V
Motor driver chip	QNF					IC1	Allegro A4988
Resistor	805	0.2ohm	0.25W	1%		S1,S2
Resistor	402	10k		10%		R4
Resistor	402	20k		10%		R1
Resistor	402	100k		10%		R2, R3
Trimpot	3mm	10k				T1