The LPC1768 mbed board featuring an ARM Cortex-M3 processor was one of the pioneering rapid prototyping boards that brought 32-bit microcontrollers to hobbyists and engineering students in India. Though newer boards have emerged, LPC1768 remains relevant in Indian engineering curricula and offers an excellent platform for learning ARM Cortex-M3 architecture. This getting-started guide covers everything Indian students need to start programming the LPC1768 mbed.
Table of Contents
- LPC1768 mbed Overview
- Key Specifications
- Getting Started in India
- Your First mbed Program
- Working with Peripherals
- Project Ideas for Engineering Students
- Learning Resources
- Frequently Asked Questions
LPC1768 mbed Overview
The mbed LPC1768 is based on NXP’s LPC1768 microcontroller with an ARM Cortex-M3 core running at 96 MHz. It was designed by ARM, NXP, and others as an educational platform and includes an integrated USB-to-serial interface for easy programming — just drag and drop a .bin file to program it.
In Indian engineering colleges, LPC1768 is used in embedded systems labs because of its Cortex-M3 architecture coverage in BE/BTech curricula, and because the online mbed compiler (now Mbed Studio) makes it accessible even on college lab computers without installing a full toolchain.
Key Specifications
- Processor: ARM Cortex-M3 at 96 MHz
- Flash: 512KB
- SRAM: 64KB (32KB local + 16KB AHB + 16KB peripheral)
- GPIO: 40 digital I/O pins
- ADC: 8× 12-bit ADC channels
- Communication: 4× UART, 3× SPI, 3× I2C, 1× CAN, USB OTG
- Ethernet: Built-in Ethernet MAC (needs external PHY on most boards)
- PWM: 6 hardware PWM channels
Getting Started in India
To start with LPC1768 mbed in India:
- Create a free account at os.mbed.com
- Download and install Mbed Studio (offline IDE) — works on Windows, macOS, Linux
- Connect LPC1768 via USB — it appears as a USB drive called “MBED”
- Compile your program and drag the resulting .bin file to the MBED drive
- Press the reset button — your program starts running
LPC1768 boards are available from Indian electronics suppliers and online for approximately ₹2500–₹4000 depending on the variant. Some college component stores stock them.
Your First mbed Program
#include "mbed.h"
// Blink LED1 on LPC1768 (LED1 is on p1.18)
DigitalOut led1(LED1);
int main() {
while(1) {
led1 = 1; // LED ON
wait(0.5); // Wait 500ms
led1 = 0; // LED OFF
wait(0.5);
}
}
// Serial output example
Serial pc(USBTX, USBRX); // USB serial
int main() {
pc.printf("Hello from LPC1768!
");
DigitalIn button(p5);
button.mode(PullUp);
while(1) {
if (!button) { // Active low with pull-up
pc.printf("Button pressed!
");
wait(0.3); // Simple debounce
}
}
}Working with Peripherals
// Analog read with 12-bit ADC
AnalogIn pot(p19); // Potentiometer on p19
float voltage = pot.read() * 3.3; // Convert 0-1 float to 0-3.3V
printf("Voltage: %.2f V
", voltage);
// PWM output (servo control)
PwmOut servo(p21);
servo.period(0.02); // 20ms period (50 Hz)
servo.pulsewidth(0.0015); // 1.5ms = centre position
// I2C example
I2C i2c(p28, p27); // SDA, SCL
char data[2];
i2c.read(0x68 << 1, data, 2); // Read from address 0x68
// UART communication
Serial sensor(p13, p14); // TX, RX
sensor.baud(9600);
sensor.printf("AT
"); // Send AT commandProject Ideas for Engineering Students
- Ethernet web server: LPC1768 has built-in Ethernet MAC — serve sensor data via web browser on college lab network
- USB HID device: LPC1768’s USB OTG can act as a keyboard or mouse
- Data acquisition system: Use all 8 ADC channels to log multiple sensors simultaneously
- CAN bus node: LPC1768 has CAN controller — implement CAN communication between two boards
- Motor controller: Use hardware PWM and interrupt-driven encoder reading for precise motor control
- RTOS demo: Mbed OS supports RTOS — demonstrate multi-threading and prioritisation
Learning Resources
- Official mbed documentation: os.mbed.com/handbook
- NXP LPC1768 User Manual: Free download from NXP website
- ARM Cortex-M3 Technical Reference Manual: ARM Developer website
- Cookbook examples on mbed.org: Hundreds of working examples for various peripherals
- Indian engineering forums: InsideIIM, IIT forums, and VTU discussion groups often share LPC1768 lab solutions
Frequently Asked Questions
Is LPC1768 still relevant for Indian engineering students in 2025?
Yes — many BE/BTech programmes in India still use LPC1768 for Embedded Systems and Microprocessors labs because of curriculum alignment with Cortex-M3 architecture theory. The concepts learned (NVIC, SysTick, bus interfaces) apply to all modern ARM processors.
Can I program LPC1768 without the online Mbed compiler?
Yes — Mbed Studio (offline IDE), Keil MDK-ARM, IAR EWARM, or GCC-based toolchains all support LPC1768. The drag-and-drop programming still works regardless of the IDE you use for compilation.
What is the difference between mbed 2 and mbed OS 5/6 for LPC1768?
Mbed 2 (classic) is bare-metal with simple APIs. Mbed OS 5/6 adds an RTOS, network stacks, and a more complex framework. For beginners and simple projects, mbed 2 is sufficient. For RTOS experiments, use Mbed OS.
How much does LPC1768 cost in India vs newer boards?
LPC1768 mbed costs ₹2500–₹4000 in India, which is expensive compared to modern alternatives like ESP32 (₹300) or STM32 Nucleo (₹1000). However, if your college syllabus requires LPC1768, it’s worth purchasing for lab work.
Can LPC1768 run a TCP/IP stack for Ethernet projects?
Yes — LPC1768 includes an Ethernet MAC and Mbed OS includes lwIP TCP/IP stack. With an external LAN8720 PHY (around ₹80 in India), you can run HTTP, TCP, and UDP on the LPC1768 — useful for industrial data acquisition projects.
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