Single-board computer

Picture a desktop computer. Now shrink the motherboard, CPU, RAM, and graphics down until everything fits on a board roughly the size of a bank card. Plug in a screen, keyboard, and power supply, and you have a working computer that cost less than a textbook. That is a single-board computer.

A single-board computer (SBC) puts all the components of a functional PC onto one printed circuit board. Unlike a microcontroller — which holds only a minimal CPU core and a few kilobytes of memory — an SBC runs a full operating system such as Linux or Android. It has megabytes or gigabytes of RAM, can store files on a microSD card or eMMC chip, and offers familiar ports: USB, HDMI, Wi-Fi, Ethernet.

The Raspberry Pi effect

The Raspberry Pi, launched in 2012 to teach programming in UK schools, accidentally became the world's favourite robot brain. A Raspberry Pi 5 runs a quad-core ARM Cortex-A76 at 2.4 GHz — faster than a mid-range laptop from 2010 — and costs around ₹5,000. Its 40-pin GPIO header lets it talk directly to motors, sensors, and other electronics, bridging the gap between "computer" and "controller" in a single board.

SBCs built for robotics and AI

Not all SBCs are equal. The NVIDIA Jetson family (Nano, Orin, AGX) adds a powerful GPU to the mix, allowing real-time computer vision and machine-learning inference on the board itself — without sending data to a cloud server. A Jetson Orin AGX can run neural networks fast enough to guide a drone or read a robot's camera at 60 frames per second. Google's Coral Dev Board adds a dedicated neural-network accelerator chip for even more efficient AI tasks.

SBC versus microcontroller

The two are complementary, not rivals. An SBC handles the "thinking" — running ROS (the Robot Operating System), processing camera images, deciding where to move. A microcontroller handles the "reflexes" — closing a motor-control loop 10,000 times per second, reading encoders, firing PWM signals. Many robots use both: an SBC as the high-level brain, one or more microcontrollers at the low-level limbs.

Why it matters

SBCs collapsed the cost of putting a real computer inside a machine. A robot that once needed a ruggedised industrial PC costing lakhs can now use a Raspberry Pi costing thousands. That shift is why robotics became a hobby, a student project, and a startup opportunity all at once.

The original Raspberry Pi 1 Model B (2012) had 256 MB of RAM — the same as an iPhone 3G from 2008. The Raspberry Pi 5 (2023) has 32× more RAM and runs roughly 40× faster.