Project idea
Enable secure, long‑range control of a railway level crossing gate via SMS commands from authorized numbers, removing the need for wired controls or constant on‑site presence. SMS keywords like OPEN/CLOSE drive a DC motor through a motor driver, while status is shown on an LCD and gate endpoints are confirmed by limit switches.​
 
Description
A SIM800L GSM module receives SMS commands and forwards them over UART to an 8051 board, which validates the sender against a programmable whitelist and actuates the gate through an H‑bridge driver. A 16×2 LCD displays live gate state, and limit switches provide end‑stop safety; power is derived from a 12V adapter with a buck stage to supply the GSM module’s required voltage.
 
Components
8051 development board with AT89S52 and programmer.​
SIM800L GSM module with antenna.​
L293D motor driver module.​
16×2 LCD display.​
12V 100 RPM DC geared motor.​
12V 2A DC power adapter.​
LM2596 buck converter module.​
4×4 matrix keypad.​
Limit switches (KW11‑3Z type).​
ABS enclosure 20×12×7.5 cm class.​
 
Features
Remote SMS control from any network range reachable by GSM, using simple OPEN/CLOSE commands.​
Programmable authorized numbers to prevent unauthorized operation.​
Live gate status on 16×2 LCD for clear operator feedback.​
Safety limit switches to stop the motor at end positions and protect mechanics.​
Robust H‑bridge motor drive suitable for 12V gate actuators.​
 
Applications
Railway level crossing control from centralized or remote stations.​
Backup/override control where wired links are unreliable or unavailable.​
Academic training in GSM, embedded C for 8051, motor control, and HMI.​
 
Project Includes:
Fully assembled and tested circuit
Circuit diagram
Source code 
(For DIY KITs - only the components will be provided)
 
Project Types:
DIY KIT(Do IT YourSelf KIT) - We are providing only components in this kit for this project
DIY KIT with Code & Circuit Connections - Along with the components, you will get the Code and the Circuit Connections file to help you build the project easily.
Readymade Breadboard - We are providing fully assembled, tested and ready-made project using plug-n-play jumper wires and breadboard with all the other components, code & circuit diagram.
Readymade Soldered - We are providing fully assembled, tested and ready-made project soldered on a PCB with all the other components, code & circuit diagram.
 
Dimensions
The main assembly fits a 200×120×75 mm ABS enclosure, equivalent to 20×12×7.5 cm for typical project builds. LCD and connectors mount on the lid or panel, and the motor/limit switches attach to the gate mechanism as per model/mechanical layout.​
 
Shipping size
Packed with padding and adapter, a practical carton is around 25×20×10 cm to accommodate the 20×12×7.5 cm enclosure and accessories securely. Allow space for shock protection and cable bends to avoid strain on connectors during transit.​
 
Weight
A comparable ABS enclosure around this size class weighs roughly 0.4 kg, providing a baseline for the assembled unit mass. Including electronics and moderate hardware, typical finished unit mass is about 0.8–1.0 kg depending on motor and mounting.​
 
Est. weight
Estimated shipping weight with adapter and carton is about 2 kg, reflecting enclosure, electronics, motor, and packed power supply mass. Heavier gear motors or larger enclosures increase the shipping weight accordingly.
 
Notes: All the products are made by LearnElectronics India and not for re-sale.