ESP32-C5

The one thing only it can do

“Why won’t my ESP32 connect to my Wi-Fi?” has, for a decade, had one overwhelmingly common answer: because the network is 5 GHz and every ESP32 radio was 2.4 GHz only. The C5 is the part that fixes this. It is the first — and as of now the only — Espressif SoC with a dual-band Wi-Fi 6 radio covering both 2.4 GHz and 5 GHz, with backward compatibility down to 802.11a/b/g/n/ac.

That is worth more than raw throughput suggests. The 2.4 GHz band is crowded with Wi-Fi, Bluetooth, Zigbee, microwave ovens and every other ESP32 in the building. Moving to 5 GHz buys a quieter spectrum, more non-overlapping channels and lower latency, which matters for anything real-time. Increasingly it also buys basic compatibility, as more installations put IoT devices on a 5 GHz SSID or run 6 GHz-capable equipment where the 2.4 GHz radio is an afterthought.

The C5 also carries 802.15.4 for Thread 1.4 and Zigbee 3.0 alongside Bluetooth LE 5, making it a superset of the C6’s radio capability. Think of it as a 5 GHz-capable C6 that trades a little power efficiency and a few GPIOs for the extra band.

Architecture and low power

A single high-performance RISC-V core at up to 240 MHz — the fastest clock in the C-series, 50% above the C6 — plus a dedicated low-power RISC-V core running at 20 to 48 MHz with its own 16 KB of LP SRAM. The LP core can execute while the main core is in deep sleep, which makes real sensor-processing-while-asleep patterns practical: poll an ADC, filter the readings, decide whether the event is worth waking up for.

384 KB of on-chip SRAM, and unlike the C6 the C5 supports in-package PSRAM (up to 8 MB), which is a meaningful advantage if you need buffer space.

Deep-sleep current is around 12 µA — the highest of the modern C-series parts, and noticeably worse than the C6’s 7 µA. Two radios and a faster core cost something. For a device that wakes every few minutes this is irrelevant; for a coin-cell sensor that sleeps for hours, it is the reason to choose a C6 or an H-series part instead.

Peripherals

• 29 GPIOs — fewer than the C6’s 30 and the C61’s 30
• Two CAN FD controllers. Not TWAI/CAN 2.0 — actual CAN FD, with the higher data rates. Only the C5 and the H4 have this. For automotive and industrial field devices, this is a strong draw.
• SDIO 2.0 slave, so the C5 can act as a Wi-Fi and Bluetooth co-processor for a host CPU
• USB Serial/JTAG only — no USB OTG
• 3 SPI, 1 I2S, 2 I2C plus 1 LP-I2C, 3 UART plus 1 LP-UART
• PARLIO, MCPWM (6 channels), RMT (4 channels), PCNT (4 units)
• 6-channel 12-bit ADC, two analogue comparator pads, a temperature sensor
• No touch sensing, no LCD or camera interface, no Ethernet MAC

Security

Hardware AES, SHA, RSA, ECC, HMAC, a digital signature peripheral for both RSA and ECDSA (with the private key held in eFuses and inaccessible to software), APM and PMP for memory isolation, XTS-AES external memory encryption, and a TRNG.

Modules and boards

ESP32-C5-WROOM-1 from $3.50, with -N8R8 (8 MB flash, 8 MB PSRAM) at $4.50 and -N16R8 at $5.00. ESP32-C5-MINI-1 is also $3.50. Bare chips: ESP32-C5HF4 and ESP32-C5HR2 at $2.50, the flash-less die at $3.00.

ESP32-C5-DevKitC-1 is $15. Third-party availability is improving — Seeed’s XIAO ESP32-C5 lands around $7, which is currently the cheapest way to experiment with 5 GHz on an ESP32.

Software support requires ESP-IDF 5.5 or later; Arduino support followed afterwards and is newer than for the C3 and C6.

Choose it when

• The device must join a 5 GHz network
• You need low latency and cannot tolerate 2.4 GHz congestion
• You need CAN FD
• You want Wi-Fi 6, BLE and Thread/Zigbee and the 5 GHz band in one chip
• You are building a gateway or border router that bridges Wi-Fi and 802.15.4

Choose something else when

• 2.4 GHz is fine and battery life matters → ESP32-C6 , lower sleep current and cheaper
• You need the lowest cost → ESP32-C3 or ESP32-C61
• You need a display or camera interface → ESP32-S3
• You need 6 GHz / Wi-Fi 6E → ESP32-E22 , but only as a host co-processor