Introduction

Taking the exact same motor-driving technique from Experiment 18 and pointing it at something practical, a small submersible water pump, controlled through the same L293D driver, switched on and off with a simple UART menu. This is a nice little taste of automated irrigation, the same basic idea scaled up in real drip-irrigation systems.

2. Scope

We'll wire the pump through the L293D in a single, fixed direction, since a pump only ever needs to run one way, and control it with a simple ON/OFF menu over UART. This reinforces the H-bridge driving skill from Experiment 18, now applied to a purpose-built actuator rather than a general motor.

3. Prerequisite

3.1 Hardware

• STM32 Nucleo-F070RB development board

• Small submersible DC water pump

• L293D motor driver IC (or breakout module)

• External power supply matched to the pump's voltage rating

• Container of water, and a second container or drain point for pumped water

• Breadboard and jumper wires

• PC with PuTTY

3.2 Software

• STM32CubeMX (standalone)

• STM32CubeIDE

• ST-LINK USB driver

• PuTTY, or an equivalent serial terminal app