A4988 स्टेपर ड्राइवर (StepStick) पिनआउट

पिन

ENABLE (active low — pulled low on the carrier, so the outputs are live when left unconnected)
MS1 / MS2 / MS3 (microstep select, pulled low: 000 full, 100 half, 010 1/4, 110 1/8, 111 1/16)
RESET and SLEEP (active low — tie them together if unused, RESET floats otherwise)
STEP (one rising edge = one microstep)
DIR (direction, sampled on each STEP edge)
VMOT + GND (8–35V motor supply — 100µF capacitor close to the pins!)
2B / 2A (coil 2) and 1A / 1B (coil 1) — one motor winding per pair
VDD + GND (3–5.5V logic)

Motor supply (VMOT)	8–35 V
Logic supply (VDD)	3–5.5 V
Output current	≈1 A per phase without heatsink; 2 A max with cooling
Microstepping	Full, 1/2, 1/4, 1/8, 1/16
Current limit	I = Vref / (8 × Rsense)
Sense resistor	0.068 Ω (Pololu) or 0.1 Ω (many clones)
STEP pulse	≥ 1 µs HIGH and LOW
Protection	Over-temperature, under-voltage lockout, crossover-current
कैपेसिटर	100 µF across VMOT/GND
आकार	15.2 × 20.3 mm

Set the current-limit pot before connecting a motor: I_max = Vref / (8 × Rsense) on most boards (0.1Ω sense → Vref 0.8V for 1A); measure Vref between the pot screw and GND.
The DRV8825 uses the same footprint and pin order except pin 10, which is VDD here and FAULT on the DRV8825.