MP6550 DC motor controller module. It can work with motors supplied with voltage from 1.8 to 22 V and current consumption up to 1.7 A. Pololu 4733

This item is a pair of motor-holding clips for the Romi chassis in white. These clips snap into the main Romi base plate, and then the motors snap into the clips. It is included as part of the white Romi Chassis Kit.

This power distribution board is designed specifically for the Romi chassis as a convenient way to access the chassis’s battery power and pass that on the rest of the electronics that make up your robot. Pololu 3541  

This RC switch converts hobby radio control pulses to digital on/off signals for use in RC switch and simple RC adapter applications. One output indicates the presence of a valid RC signal, and the other indicates whether the switch is active. The activation threshold and direction are configurable, and a safe-start feature reduces the likelihood of unexpected activation. Pololu 2801

Motor with 37 mm diameter and 54 mm length, 50:1 metal gear, 24 V operating voltage, 0,1 A to 3 A power consumption, 200 RPM speed and 23 maximum torque. Pololu 4683

Module with a distance sensor with a range of up to 130 cm. It has a digital output that generates a pulse with a width proportional to the measured length. Pololu 4071

The FS90 analog servo from FEETECH is a great general-purpose micro servo at a great price. Servo horns and associated hardware are included.

Key specs at 6 V: 0.10 sec/60°, 21 oz-in (1.5 kg-cm), 9.0 g.

3-pin cable with a length of 30 cm and 28 AWG. A one-sided JST ZH 3-pin female connector that is compatible with the 3-pin connector of the Sharp GP2Y0A51 analog distance sensors. Polol 2411

Motor with 37 mm diameter and 65 mm length, 10:1 metal gear, 12 V operating voltage, 0,2 A to 5,5 A power consumption, 1000 RPM speed, 4,9 maximum torque and 64 CPR encoder. Pololu 4758

Miniature, analog servomechanism with dimensions 20.0mm × 8.3mm × 17.3mm and weight 4.4g, power supply 4.8 ... 6V, maximum torque 0.6kg / cm (with 6V power supply). Pololu 3420

Module with 13 QTR type optocoupler with RC (digital) output. The module operates from 2.9 V to 5.5 V, detects objects at a distance of up to 40 mm. The sensor will be used in projects that require detection of changes in the ground, e.g. in linefollower robots. Pololu 4153

Motor with 37 mm diameter and 54 mm length, 70:1 metal gear, 24 V operating voltage, 0,1 A to 3 A power consumption, 140 RPM speed and 31 maximum torque. Pololu 4684

The Tic T834 USB Multi-Interface Stepper Motor Controller makes basic control of a stepper motor easy, with quick configuration over USB using our free software. The controller supports six control interfaces: USB, TTL serial, I²C, analog voltage (potentiometer), quadrature encoder, and hobby radio control (RC).

DRV8711 stepper motor driver module powered by 8-50V voltage and 4A operating current. The controller allows you to control the movement of the engine with up to 9 different resolutions. Configuration via SPI interface. Pololu 3730

These universal aluminum mounting hubs allow you to mount custom wheels and mechanisms to 8 mm diameter motor shafts. The set includes two hubs, four M3 set screws for securing the hubs to motor shafts, and one 1.5 mm Allen wrench for use with the set screws.

Module with ACS724LLCTR-30AU current sensor with a measuring range of direct and alternating current from 0 to 30 A. It communicates via an analog interface. Pololu 4046

Pololu 2450

This board is a simple carrier of Broadcom’s bidirectional ±50A ACHS-7125 Hall effect-based linear current sensor, which offers a low-resistance (~0.7 mΩ) current path and electrical isolation up to 3 kV RMS. Pololu 4034

Pololu 5V Step-Up/Step-Down Voltage Regulator S7V7F5

Pololu - 1524