ESP-IDF C5 - Lecture 1 · Developer Portal

Table of Contents

This lecture introduces the ESP32-C5 and its dual-band Wi-Fi 6 radio, then explains how to configure the 2.4 GHz and 5 GHz bands using the ESP-IDF Wi-Fi driver.

WS00C - This article is part of a series.

Part 1: ESP-IDF Workshop: ESP32-C5

Part 2: This Article

Part 3: ESP-IDF C5 - Assign. 1.1

Part 4: ESP-IDF C5 - Assign. 1.2

Part 5: ESP-IDF C5 - Lecture 2

Part 6: ESP-IDF C5 - Assign. 2.1

Part 7: ESP-IDF C5 - Assign. 2.2

Part 8: ESP-IDF C5 - Lecture 3

Part 9: ESP-IDF C5 - Assign. 3.1

Part 10: ESP-IDF C5 - Assign. 3.2 (Optional)

Part 10: ESP-IDF C5 - Assign. 3.3

Part 11: ESP-IDF C5 - Lecture 4

Part 12: ESP-IDF C5 - Assign. 4.1

Part 13: ESP-IDF C5 - Assign. 4.2

Introduction
#

The ESP32-C5 is one of the latest Espressif SoCs, and it stands out for its wide range of connectivity options. In addition to Bluetooth Low Energy (LE) and the IEEE 802.15.4 protocol (used by Thread and Zigbee), it’s the first Espressif SoC to support dual-band Wi-Fi 6, covering both the 2.4 GHz and 5 GHz bands.

Wi-Fi 6 and the 5 GHz Band
#

Wi-Fi 6, also known as 802.11ax, is one of the latest generations of the Wi-Fi standard. Compared to previous generations, it introduces several improvements that are particularly useful for IoT applications, such as:

Target Wake Time (TWT): allows devices to negotiate when and how often they wake up to send or receive data, reducing power consumption.
OFDMA (Orthogonal Frequency-Division Multiple Access): lets multiple devices share the same channel more efficiently, lowering latency in crowded networks.
MU-MIMO (Multi-User, Multiple Input, Multiple Output): increases network capacity by allowing the access point to communicate with several devices at the same time.
BSS coloring: helps maintain stable connectivity in areas with many overlapping Wi-Fi networks.

The 5 GHz band adds another advantage on top of these Wi-Fi 6 features. Since it’s less commonly used than the 2.4 GHz band, it typically suffers from less interference and congestion. This makes it a good fit for applications that need lower latency and more reliable throughput, such as live streaming, IP cameras, or other high-bandwidth IoT use cases. Being able to choose between 2.4 GHz and 5 GHz also lets you assign different devices to different bands depending on how critical their connectivity is.

Note

The ESP32-C5 does not support simultaneous dual-band operation. It can operate on only one band, 2.4 GHz or 5 GHz, at any given time.

Configuring the Wi-Fi Band Mode
#

To use the 5 GHz band on the ESP32-C5, you need to set the Wi-Fi band mode using the esp_wifi_set_band_mode() API, which is part of the esp_wifi component. This function accepts a wifi_band_mode_t value:

WIFI_BAND_MODE_2G_ONLY: restricts operation to the 2.4 GHz band.
WIFI_BAND_MODE_5G_ONLY: restricts operation to the 5 GHz band.
WIFI_BAND_MODE_AUTO: the default mode, it scans both bands and connects to the access point with the strongest signal when the same SSID is broadcast on both.

#include "esp_wifi.h"

// Restrict the ESP32-C5 to the 5 GHz band only
esp_wifi_set_band_mode(WIFI_BAND_MODE_5G_ONLY);

Conclusion
#

In this lecture, you learned that the ESP32-C5 is Espressif’s first SoC with dual-band Wi-Fi 6 support, and why the 5 GHz band can be a good choice for latency-sensitive or high-throughput IoT applications. You also saw how to select the Wi-Fi band using esp_wifi_set_band_mode(). In the next assignment, you will apply this knowledge to connect your ESP32-C5 DevKit to a 5 GHz Wi-Fi network.