28BYJ-48 Geared Stepper Motors and ULN2003 Driver Kits

28BYJ-48 geared steppers: choose the motor voltage and the exact kit contents

Shop 28BYJ-48 geared stepper motors in selected 5V and 12V versions, ULN2003 driver boards, motor-and-board combinations and multipacks. The collection also includes cable and remote-control-board choices and a separate SA8302 alternative driver module. A product title that mentions a motor plus ULN2003 does not mean both ship with every option. Confirm the selected voltage, variant name and product-specific package list before ordering for a prototype, class set or production repair.

Understand the motor before selecting a board

The familiar 28BYJ-48 is a compact geared stepper-motor family commonly shown with a five-wire lead and four phase-drive connections. A gearbox converts the internal rotor's motion into slower output-shaft movement and greater available output torque within the limits of the particular motor. A stepper advances in commanded increments under suitable sequencing, but an open-loop system cannot detect missed steps or verify its absolute position without additional sensing. A small geared motor is suited to appropriately sized mechanisms, not an unrestricted heavy-load actuator just because a seller calls it 'high torque'.

Some product descriptions quote a 5.625-degree internal stepping figure, a nominal 1/64 reduction or a corresponding output angle. Other product data quotes a different nominal gear ratio. Actual gear-train ratio and half-step or full-step drive sequence can change the number of commanded steps per output revolution. For an application that requires accurate positioning, calibrate the selected motor's actual output rotation and account for backlash and load rather than adopting one universal 2,048- or 4,096-step figure. Torque, start rate, running speed and repeatability depend on drive voltage, sequence, gearing, power supply, load and temperature; the various listing-level figures are not guarantees for every option here.

What is actually in the selected variant?

• Motor only: options such as '28BYJ-48 Motor', '28BYJ-48-5V', 'DC 5V stepper motor', 'DC 12V stepper motor', '5V Motor' and '12V motor' designate a motor selection, not necessarily a driver. A 5V and a 12V winding version must be matched to its own rated supply.
• ULN2003 board only: options such as 'ULN2003 Module', 'ULN2003 Green', 'ULN2003 Blue', 'Driver board for 5V' and 'Driver board for 12V' identify assembled drive boards without necessarily supplying a motor. A board's connector can physically fit a motor whose rated voltage or pin order is wrong; check both, not just the plug.
• Motor plus driver: variants labeled '28BYJ-48 and ULN2003', '5V and Driver board', '12V and Driver board', 'With Blue Board' or 'motor with module' indicate combinations on their particular product page. Compare the individual listing's package contents, board color, voltage and quantity rather than treating these labels as identical across suppliers.
• Multipacks: this collection contains 1-, 2-, 3-, 5-, 10-, 15-, 20-, 25- and 30-set selections, alongside separate motor-only and board-only packs. One 10-set listing specifies ten 5V motors plus ten ULN2003 boards for its sole 'No plug' option, and a three-piece experimental listing describes three motors and three boards. Elsewhere a title saying '10PCS motor + board' sits above variant values for motor or driver board, so the selected SKU and the individual package list must decide the actual count.
• Wires and remote-control options: one listing offers 'Motor-1PCS', 'M-F-20cm-20pin' and 'M-F 2pc 5V motor kit' as different selections. Another offers 'Driver Board', 'Suit', 'Suit Cable' and 'USB to DC Cable', with an infrared remote-control driver-board description. Do not infer that the cable, remote, batteries, MCU or motor is included in a board-only or cable-only selection.
• Alternative SA8302 board: a 'SA8302 no shell' or 'SA8302 with shell' option is an alternative MOSFET/H-bridge-based module advertised for certain 28BYJ-48 applications, not a ULN2003 chip or a motor. Check its own supply, control scheme, connector pinout and specific motor compatibility rather than treating 'replace ULN2003' as a universal drop-in guarantee.

ULN2003 driver-board architecture

A conventional ULN2003-family IC is a seven-channel low-side Darlington sink-driver array. Common 28BYJ-48 modules use four of those channels to energize the motor's phase windings in a timed sequence; the A/B/C/D LEDs on some boards indicate control states. The board does not contain position feedback or generate motion commands autonomously. The microcontroller, its program, a suitable supply and the selected motor complete a working system. 'For Arduino', 'for PIC', 'AVR' or 'ARM' is an application description, not proof that a controller, cable, library or universal pinout is included.

A Darlington stage drops voltage and dissipates heat when switching a winding. Its permissible load current depends on the exact IC, simultaneous outputs, duty cycle and thermal environment. A board described as 'high-power' does not inherit a guaranteed continuous current rating. Verify the chip's inductive-load clamp arrangement and common connection against the exact board's manufacturer documentation. The five-wire motor's winding common, motor power and the MCU's logic/reference ground must be assessed using the actual selected hardware's schematic; do not extrapolate a seller's connection diagram across blue, green, infrared-control or SA8302 boards.

5V versus 12V: the essential boundary

Several listings show both voltage versions in one title, but each purchase uses the chosen option. The 5V motor is not specified to run continuously at 12V merely because a '12V and Driver board' option is shown next to it. Conversely, a 12V motor is not guaranteed to start or deliver rated torque at 5V. Match the motor's label, its winding resistance and the particular driver-board supply arrangement. A board description may say it accepts 5–12V; that describes the board's stated input range, not a universal safe voltage for every motor plugged into it. Neither USB-to-DC cable presence nor a connector's physical fit establishes a correct motor supply.

The motor winding resistance and current can differ between 5V and 12V versions. Do not copy one listing's '200 ohms' or '250mA' line to all variants. Compare the exact motor datasheet, board schematic and supply capability where current budget matters. An external power source may be required, and the product pages in this collection do not establish that batteries or a regulated supply are included with every motor or kit.

Drive mode, gearing and motion performance

Product pages alternate among 'four phase', 'five wire', 'two phase', 'hybrid' and 'variable reluctance' labels, sometimes on nominally similar items. Those seller classifications should not replace an examination of the actual lead count and winding topology. A standard five-wire unipolar arrangement is commonly paired with a ULN2003 sink board. Do not assume that an arbitrary four-wire bipolar driver accepts it unchanged, or that a five-wire motor can be converted for a different driver without verifying its winding construction and making an intentional engineering modification.

Full-step and half-step drive sequences trade command count, vibration, torque profile and speed. The gearbox adds backlash, making reversal and tiny incremental movements different from unloaded unidirectional rotation. At higher step rates the available torque generally falls; starting under load, acceleration, resonance and stopping behavior need to be evaluated in the actual mechanism. Phase LEDs show commanded states, not proof of achieved shaft motion. Where the listing gives no-load frequency, pull-in torque or noise measured under particular conditions, do not treat them as guaranteed performance in a customer's enclosure or load.

Buying checklist for a reliable match

1. Select shipment level: choose motor only, ULN2003 board only, matching motor-plus-board pair, cable/remote-control set or SA8302 alternative. The title can describe several mutually exclusive choices.
2. Lock the voltage: choose 5V or 12V motor and verify the board and available supply are suitable for that exact winding. A label such as 'Driver board' without voltage merits a review of the specific product detail.
3. Confirm the physical fit: check the motor's five-wire harness, plug pitch and keying, shaft shape/length, case diameter, mounting tabs, cable length and available clearance against the specific listing. A '28BYJ-48' keyword alone does not guarantee identical mechanical dimensions across suppliers.
4. Confirm control needs: the simple ULN2003 module needs a controller to sequence its inputs; a remote-control board may implement a different control interface. A USB cable can supply or connect only the role documented for that product, not automatically add motion control.
5. Size the load: consider output-shaft torque at intended speed, gearbox backlash, radial/axial mechanical loading, available supply current, duty cycle and driver heat. Add feedback if the application cannot tolerate missed steps.
6. Count units per option: '5 set' generally describes a multi-set selection, while '5V' is a voltage, not a pack count. A 'Blue 10pcs' board option is not necessarily ten motors; a 'Blue 10set' option is different. Check the order variant before purchasing in bulk.

Typical selection paths

For a replacement motor in an existing 5V assembly, select the motor-only 5V version after checking shaft and connector details. For an introductory MCU project, select an explicit 5V motor-and-ULN2003 combination, then separately confirm controller, suitable power and jumper leads. For an established 12V mechanism, choose the specific 12V motor option and validate the matching board rather than borrowing a 5V kit's specification. For teaching multiple identical setups, compare the stated counts of complete motor-and-board sets with motor-only or board-only multipacks. The selected product variant and component documentation, not the collection title, control actual contents and engineering limits.