Day 61: UART vs SPI vs I2C — How Embedded Devices Communicate (Explained Simply)
Welcome to Day 61 of 100 Days of Tech! 🚀
After learning:
Embedded Systems
RTOS
Firmware
Real-world embedded applications
today we answer one of the most important embedded engineering questions:
👉 How do chips actually communicate inside electronic systems?
The answer lies in communication protocols.
This video explains the three most important ones:
✔ UART
✔ SPI
✔ I2C
in a simple, practical way.
🔹 What you’ll learn in this video
✔ What communication protocols are
✔ Why microcontrollers need them
✔ UART basics (TX/RX communication)
✔ SPI basics (fast master-slave communication)
✔ I2C basics (two-wire multi-device communication)
✔ Where each protocol is used in real devices
✔ Which one engineers choose and why
🔹 UART (Universal Asynchronous Receiver Transmitter)
Simple serial communication
Uses:
TX (Transmit)
RX (Receive)
Common in:
Debugging
GPS modules
Bluetooth modules
🔹 SPI (Serial Peripheral Interface)
Fast communication
Master-slave model
Multiple lines:
MOSI
MISO
SCLK
CS
Common in:
Displays
Memory chips
High-speed sensors
🔹 I2C (Inter-Integrated Circuit)
Only 2 wires:
SDA
SCL
Used when many devices share one bus.
Common in:
Sensors
RTC modules
EEPROM
🔹 Simple Comparison
UART = simplest
SPI = fastest
I2C = most compact wiring
🔹 Real Device Example
Microcontroller ↔ Sensor ↔ Display ↔ Memory
All of these depend on protocol selection.
💼 Career relevance
This topic is critical for:
Embedded Engineer interviews
Firmware development
IoT system design
Electronics debugging
⏱️ Chapters
00:00 Intro
00:30 Why protocols matter
01:20 UART explained
02:40 SPI explained
04:10 I2C explained
05:40 Comparison
06:20 Real-world use
🏷️ Tags
UART explained, SPI explained, I2C explained, communication protocols embedded systems, UART vs SPI