CHIPSEA CST85F01 480 MHz Cortex-M4 MCU supports dual-band WiFi 6 and Bluetooth 5.0 LE

CHIPSEA CST85F01 is an Arm Cortex-M4F microcontroller clocked at up to 480 MHz and designed for IoT applications with dual-band (2.4/5.0 GHz) WiFi 6 with TWT (Target Wake Time) support, Bluetooth 5.0 LE, and a range of I/Os.

Following the recent availability of 2.4 GHz WiFi 6 IoT chips such as Espressif Systems ESP32-C6 and Bouffalo Lab BL616, CHIPSEA CST85F01 offers an alternative with dual-band WiFi 6 connectivity while we are waiting for the launch of the ESP32-C5 RISC-V microcontroller.

CST85F01 specifications:

CPU core – Arm Cortex-M4F CPU with MPU and FPU @ up to 480 MHz
Memory – 992 KB SRAM, SDR/DDR PSRAM interfaces
Storage – 752 KB ROM, 8 Mbit to 128 Mbit flash
WiFi features
- 2.4GHz/5GHz Wi-Fi 6
- Data rates up to 286.8 Mbps (Tx) and 229.4 Mbps (Rx) with 20/40 MHz bandwidth
- Rx sensitivity – -98dBm in 11b mode, -93.5dBm in MCS0 HT20 mode
- Tx power – Up to 20dBm in 11b mode, 18dBm in HT/VHT/HE40 MCS7 mode
- STA, AP, Wi-Fi Direct modes
- Wi-Fi 6 TWT
- MU-MIMO, OFDMA
- Security – WEP, WPA, WPA2, WPA3-SAE Personal, MFP
Bluetooth features
- “All the mandatory and optional” features of Bluetooth 2.1+EDR, 3.0, 4.x, 5
- 125Kbps, 500Kbps, 1Mbps, 2Mbps data rates in BLE mode
- Rx sensitivity
  - -95dBm in BT classic mode
  - -94.5dBm in BT EDR 2Mbps mode and -88.5dBm in BT EDR 3Mbps mode
  - -97dBm in BLE 1Mbps mode
  - -107.5dBm in BLE coded 125Kbps mode
- Tx power – Up to 13 dBm in BT classic mode and 10 in BT EDR mode
Peripherals
- USB 2.0
- SDIO, SDMMC
- Up to 24x GPIOs with external level/edge trigger/wakeup
- UART, I2C, PWM, SPI
- Audio I2S
- Analog – 9-channel 14-bit ADC
- Low power timer and watchdog
Security
- Hardware crypto accelerator with AES, RSA, HASH, ECC
- True Random Number Generator (TRNG)
- 512-bit eFuse
Supply voltage – 2.3 to 5V DC (Typical: 3.3V)
Power Consumption according to information on “ArrowSolution“.
- 40uA deep sleep
- 21mA Rx
Package – QFN48, 5x5mm
Temperature Range – 20 to +80°C

The microcontroller is supported in FreeRTOS real-time operating system and is designed for IoT devices, wireless devices, and TV/STB dongles. I’m not quite sure what the latter means in this context, or they just mean some advanced WiFi or Bluetooth remote controls.

I was unable to find details on the CHIPSEA website, but I could locate the English datasheet and some documentation in Chinese on Sekorm. The downside is that you need to bring your mobile phone number to complete the downloads. Here’s a mirror link for the datasheet where you’ll find a few more details.

Further investigative work led me to a CST85F01 module with three SMA connectors for 2.4 GHz and 5.0 GHz WiFi antennas, and a Bluetooth antenna, as well as a micro USB port, some GPIOs, and another connector used to plug the module into a larger demo board (cst85_wblink) giving easier access to all I/Os including some audio ports. I found the hardware on OpenHarmony’s Gitee account which means the module and board are supported by the Chinese operating system.

What I’m unable to find is somewhere to purchase the chip, module, and/or development board apart from the aforementioned Sekorm website. It’s unclear whether it will ever find a market outside of China, but it offers greater CPU performance, memory, and storage than the upcoming ESP32-C5 so more demanding IoT applications may benefit from it.

Thanks to Copercini for the tip.

Jean-Luc Aufranc (CNXSoft)

Jean-Luc started CNX Software in 2010 as a part-time endeavor, before quitting his job as a software engineering manager, and starting to write daily news, and reviews full time later in 2011.