24/08/2026
UART vs I²C vs SPI — Which One Should You Choose? 🔌
Three of the most common communication protocols in embedded systems — but they solve different problems.
🔵 UART
→ Simple point-to-point communication
→ 2 wires: TX & RX
→ No clock line
→ Great for debugging, GPS, Bluetooth & serial communication
🟢 I²C
→ Multiple devices on the same bus
→ 2 wires: SDA & SCL
→ Address-based communication
→ Commonly used with sensors, EEPROM, RTC & PMIC
🟣 SPI
→ High-speed synchronous communication
→ SCLK, MOSI, MISO & CS
→ Full-duplex communication
→ Ideal for Flash, displays, ADC/DAC & high-speed peripherals
Quick rule:
UART → Keep it simple
I²C → Connect multiple devices with fewer pins
SPI → Choose speed & throughput
If you’re learning VLSI, Embedded Systems or SoC Design, understanding these protocols is essential.
💬 Which protocol do you use most — UART, I²C or SPI?
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