Communication Protocols

Learn how embedded devices exchange data. Master UART, SPI, I2C, CAN, and USB from fundamentals to driver-level implementation.

Phase 1

Communication Basics

Understand why communication exists, how data flows, and how basic channel parameters are classified in embedded systems.

Module 1 — Communication Basics

What is Communication?

Why embedded components cannot work in isolation and how data flows between a CPU and its peripherals.

Host vs Device

Who initiates communication and who responds. The master-slave model in embedded protocols.

Wired vs Wireless Communication

Physical signals over copper vs electromagnetic waves through air. Why wired protocols dominate embedded firmware.

Parallel vs Serial

How bits move between devices: simultaneously over multiple wires or sequentially over a single line.

Synchronous vs Asynchronous

Clock-based vs timing-based synchronization. The fundamental difference between protocols like SPI and UART.

Simplex, Half Duplex, and Full Duplex

How devices manage communication direction: one-way transfer, alternating two-way, or simultaneous bidirectional signals.

Baud Rate vs Bit Rate

Two terms every embedded engineer confuses. What they measure and why the difference matters in real hardware.

Clock, Data, and Timing Basics

Setup time, hold time, and clock edges. The timing rules that every synchronous protocol is built on.

Phase 2

Digital Electronics Needed for Protocols

Bridge the gap between basic voltage and communication protocols. Master the essential electronics concepts required for stable interfaces.

Module 2 — Digital Electronics Basics

HIGH and LOW Logic Levels

How threshold voltages define logic states, noise margins, and signal margins in SPI, UART, and I2C.

Pull-Up and Pull-Down Resistors

Preventing floating inputs. Crucial for open-drain I2C buses, active-low button interrupts, and stable startup states.

Open Drain vs Push Pull

The key differences in output stage drivers. Why I2C relies on open-drain while SPI uses push-pull.

Tri-State Logic

Understanding high-impedance (Hi-Z) states. Crucial for shared buses, memory buses, and multi-slave SPI lines.

Clock Signal Basics

What a clock signal is, how it operates, and why synchronous protocols rely on it.

Rising Edge and Falling Edge

Triggers in communication. How CPOL and CPHA configure edge sampling in SPI, and how rising/falling edges dictate timing.

Coming Soon

Data Sampling Basics

How receivers align internally to capture stable signals. Crucial for UART start-bit synchronization and SPI timing.

Coming Soon

Noise in Communication

Electromagnetic interference, ground loops, and crosstalk. Valuable practical concepts for robust hardware design.

Coming Soon

Signal Integrity Basics

Simple guides to long wires, ground return paths, noise shielding, and preventing signal distortion.

Coming Soon

Phase 3

Serial Communication Fundamentals

Universal concepts across all serial protocols. Master frames, error checking, addressing, and arbitration before learning specific buses.

Module 3 — Serial Fundamentals

Start Bit

Line transition triggering. How asynchronous receivers detect that a new frame is beginning.

Coming Soon

Stop Bit

Frame bounding. Signals that return serial buses to their idle HIGH state.

Coming Soon

Parity

Basic single-bit error checking. Even vs odd parity, how it works in UART, and its detection limits.

Coming Soon

ACK/NACK

Acknowledgment signaling. How receiving devices let transmitters know data was successfully processed (essential for I2C).

Coming Soon

CRC & Checksums

Cyclic Redundancy Checks and mathematical verification. Critical for reliable data checking on CAN and USB packets.

Coming Soon

Addressing

Targeting devices on shared buses. 7-bit vs 10-bit master-slave addressing in I2C setups.

Coming Soon

Arbitration

Resolving bus contentions. How multi-transmitter systems like CAN determine which packet has priority without data loss.

Coming Soon

Multi-Master Bus Topology

Managing networks where multiple nodes can initiate communication. Challenges, clock synchronization, and priority rules.

Coming Soon

Phase 4

UART

The simplest embedded protocol. No shared clock, just two wires and agreed timing. Used everywhere from GPS modules to debug consoles.

UART — Coming Soon

Articles Coming Soon

UART content is being prepared.

Coming Soon

Phase 5

SPI

High-speed full-duplex communication. Used for Flash memory, SD cards, and fast sensors where throughput matters.

SPI — Coming Soon

Articles Coming Soon

SPI content is being prepared.

Coming Soon

Phase 6

I2C

Two wires, many devices. The go-to protocol when you need multiple sensors and peripherals on a single shared bus.

I2C — Coming Soon

Articles Coming Soon

I2C content is being prepared.

Coming Soon

Phase 7

CAN

Built for automotive reliability. Noise-resistant, long-distance, multi-node communication used in every modern vehicle.

CAN — Coming Soon

Articles Coming Soon

CAN content is being prepared.

Coming Soon

Phase 8

USB Basics

Universal Serial Bus. The protocol behind every PC peripheral. Learn the enumeration process, device classes, and embedded USB stack basics.

USB Basics — Coming Soon

Articles Coming Soon

USB content is being prepared.

Coming Soon