Wireless for Embedded

Introduction

Not every embedded device plugs into Ethernet. Wireless links trade cables for radio complexity: antennas, protocols, pairing, power, and interference. This article surveys options you meet in IoT and robotics courses — Wi-Fi, Bluetooth, LoRa, Zigbee, and others — with honest trade-offs for range, throughput, and battery.

Pair with Computer networks for TCP/IP and MQTT and IoT messaging for application patterns on top.

Pick radio by job

Job	Often use	Range (typical)
High data, web, MQTT	Wi-Fi	Building
Phone / sensor, low power	Bluetooth LE	Room
Long range, tiny packets	LoRa / LoRaWAN	km (line of sight)
Home automation mesh	Zigbee, Z-Wave	House
Simple remote control	433 MHz ASK	Tens of meters

No single radio wins all — requirements first.

In plain terms

Wi-Fi is a shouting megaphone (fast, hungry). Bluetooth LE is a whisper across the room. LoRa is a foghorn across the valley — slow but far.

Wi-Fi (2.4 / 5 GHz)

Built into ESP8266, ESP32, many Linux modules. Full IP stack — HTTP, MQTT, TLS.

Pros	Cons
High throughput	Power hungry
Home/office infra exists	Association can be fiddly
Direct internet path	Many devices on one AP

See Connectivity architecture for provisioning without hardcoded passwords.

Bluetooth / Bluetooth Low Energy (BLE)

Classic Bluetooth — audio, serial profile. BLE — sensors, beacons, phone apps, low duty cycle.

Good for	Less good for
Wearables, config from phone	Streaming video
Battery sensors	Long-range outdoor

ESP32 includes BLE; nRF52 specializes in ultra-low power BLE.

Videos

How Bluetooth Works

The truth about Bluetooth 5 - Gary explains

LoRa and LoRaWAN

LoRa = radio modulation (chirp spread spectrum) — long range, low bitrate. LoRaWAN = network protocol on top (gateways, regions, join procedure).

LoRa	LoRaWAN
Point-to-point possible	Star-of-stars via gateways
You define protocol	Standardized MAC

Typical: soil sensor in field → LoRa module → gateway → internet.

Throughput — kilobits class, not video. Range — km with clear line of sight and legal power limits.

Videos

#112 LoRa / LoRaWAN De-Mystified / Tutorial

LoRa/LoRaWAN tutorial 2: What is LoRa and LoRaWAN

Zigbee

Low-power mesh for smart home (lights, sensors). Uses 2.4 GHz; different stack than Wi-Fi. Philips Hue and others use Zigbee to hubs.

Strength	Weakness
Mesh extends range	Needs coordinator/hub
Low power	Not for IP directly

Video

What is ZIGBEE And How It Works?

When evaluating smart-home products, read comments and specs critically — compare claims to what you learned in Computer networks.

433 MHz and simple RF

Cheap ASK/OOK modules for remotes and toys. No standard stack — you define encoding. Easy range in lab; no encryption by default.

NFC / RFID

Very short range — tap to pair, access cards. RFID tags powered by reader field. Useful for identification, not sensor networks.

Licensed cellular (4G/5G/NB-IoT)

When device must work anywhere with SIM — trackers, remote pumps. Higher cost and power; module + data plan.

Decision checklist

How much data per day? (bytes vs megabytes)
Battery or mains?
Range — room, building, campus, global?
Latency — milliseconds or minutes?
Existing infrastructure — Wi-Fi on site? LoRa gateway? Phone BLE?

Document choice in system architecture.

Relevant topics

Starting points

Fill decision table for your project — justify one radio.
Measure Wi-Fi current on ESP32 — TX vs deep sleep.
Pair BLE device with phone — list GATT services.
Compare LoRaWAN vs MQTT-over-Wi-Fi for one use case.

Focus points

Antenna placement matters — metal enclosure kills range.
Regulatory power limits per country.
Security — encrypt application data; do not trust open 433 MHz.
Hybrid — MCU + Wi-Fi for cloud + BLE for phone setup is common.

Key points

Wi-Fi for IP and bandwidth; BLE for low-power short range; LoRaWAN for long-range tiny data.
Zigbee meshes smart-home devices; usually not raw IP.
Choose radio from data, power, range, infrastructure — not datasheet hype.
Videos supplement theory; always map claims back to your requirements.