ESP32-C5: the first ESP32 on 5 GHz Wi-Fi, and what it means for your toys

The ESP32-C5 is the first Espressif chip that can use 5 GHz Wi-Fi, on top of the 2.4 GHz band every earlier ESP32 used. It went into mass production on 30 April 2025. For a toy at home, the main gain is not speed: it is getting away from a 2.4 GHz band packed with the neighbours’ routers, household appliances and Bluetooth gadgets.

If you have not compared the ESP32 family yet, read which ESP32 board to pick first. This lesson picks up from there.

What is inside the ESP32-C5

Numbers from Espressif’s announcements:

	ESP32-C5
Main core	32-bit RISC-V, single core, up to 240 MHz
Low-power (LP) core	up to 40 MHz
Wi-Fi	Wi-Fi 6 on 2.4 GHz and 5 GHz
Bluetooth	Bluetooth 5 (LE)
802.15.4	yes, for Thread and Zigbee
SRAM / ROM	384 KB / 320 KB
GPIO	up to 29
Extra memory	external PSRAM supported

Two details worth knowing: in Wi-Fi 6 (802.11ax) mode the chip uses 20 MHz channels, while older 802.11b/g/n modes can use 20 or 40 MHz. It also supports Target Wake Time (TWT), which lets a device sleep longer without dropping off the network, as long as the router is Wi-Fi 6 too.

Compared with the chips you already know

	ESP32-C3	ESP32-C6	ESP32-C5
Wi-Fi bands	2.4 GHz	2.4 GHz	2.4 + 5 GHz
Standard	Wi-Fi 4	Wi-Fi 6	Wi-Fi 6
Main core speed	160 MHz	160 MHz	240 MHz
Thread / Zigbee	no	yes	yes
SRAM	400 KB	512 KB	384 KB

So the C5 is roughly a C6 with a 5 GHz band and a faster core, but slightly less SRAM.

How 2.4 GHz and 5 GHz differ

	2.4 GHz	5 GHz
Non-overlapping channels	3 (1, 6, 11)	many times more
Crowding	busy; shared with microwave ovens, cordless phones, Bluetooth	quieter
Range	longer	shorter, worse through walls

One Wi-Fi vendor’s guide gives rough figures of 75–100 ft (about 23–30 m) for 2.4 GHz and 25–35 ft (about 8–11 m) for 5 GHz at full speed. Real numbers depend on walls, antennas and the router, so treat these as a sketch.

5 GHz does not reach further. It gives you quieter air. If your problem is distance, switching to 5 GHz will not fix it.

Worked example: how much bandwidth does a toy really need?

Take a remote-control car that streams sensor values to a web page on your phone.

1. One message holds angle, speed, battery and a timestamp: about 64 bytes of JSON.
2. Sent 20 times a second: 64 × 20 = 1,280 bytes per second.
3. In bits: 1,280 × 8 = 10,240 bits per second, about 10 kbit/s.
4. Even 1 Mbit/s, the slowest 802.11b rate, is about 100 times more than that.

So the car is not short of speed. What makes it stutter is lost packets and waiting for airtime in a crowded band, and that is exactly what 5 GHz helps with.

Bandwidth starts to matter for things that stream images or audio continuously. Espressif itself names IP cameras and streaming devices among the products that benefit from 5 GHz.

When 5 GHz helps a toy

• An apartment or dorm where you can see dozens of Wi-Fi names. The 2.4 GHz band is so busy the board keeps dropping; on 5 GHz it settles down.
• Shows and competitions with hundreds of phones in the room, Bluetooth on.
• Things that must respond quickly, such as quiz buzzers going through the router. Steady latency matters more than average speed.
• The board sits near the router, in the same or the next room.

When it does not help

• The board lives in the garden or garage, several walls from the router. Stay on 2.4 GHz.
• The project uses ESP-NOW between two boards with no router (see the ESP-NOW remote lesson). Router congestion is not your problem.
• You need Bluetooth Classic, for example for a speaker. The C5 does not have it.

Getting started with code

• Arduino: the Arduino core for ESP32 3.3.3 lists the ESP32-C5 as supported (3.3.0 did not yet). Update the board package in the Arduino IDE, then pick an ESP32-C5 board.
• ESP-IDF: initial support arrives in v5.5. Use idf.py set-target esp32c5.
• Choosing a band: if your router uses one network name for both bands, the board picks for itself. The easiest way to force a band is to give the 2.4 GHz and 5 GHz networks different names on the router and connect the board to the one you want.

Common mistakes

• Expecting 5 GHz to reach further. It is the opposite. If the board drops as you walk away, try 2.4 GHz.
• Reusing pin numbers from a C3 or C6 board without checking. The C5 has up to 29 GPIOs and every board maps them differently. Always open the pinout of the board you bought.
• An old Arduino core. Version 3.3.0 and earlier have no C5 option. Update before you blame the board.
• Buying a C5 for Bluetooth audio. There is no Bluetooth Classic.
• Expecting every Wi-Fi 6 feature from an old router. Features like TWT need a Wi-Fi 6 router. On a Wi-Fi 4/5 router the board still connects, just without those features.

Most toys do not need speed. They need a steady link. If 2.4 GHz is steady at your place, the board you already have is enough.

Sources

• ESP32-C5 Now in Mass Production — Espressif
• Espressif’s ESP32-C5 is now in mass production — Espressif Developer Portal
• Espressif announces ESP32-C5 (2022) — Espressif
• ESP32-C5 product page — Espressif
• Arduino core for ESP32 3.3.3 supported SoCs — Espressif Component Registry
• Wireless Modes and Channels — WatchGuard Docs