RISC-V based wireless MCU

25 November 2020 Telecoms, Datacoms, Wireless, IoT

Espressif launched its ESP8266 in 2014 and ESP32 in 2016. The ESP8266, with its Wi-Fi-only MCU (microcontroller), facilitated simple connectivity use cases, whereas the ESP32 addressed use cases that required dual connectivity (Wi-Fi + Bluetooth/Bluetooth LE), considerably more computing power, or strong security features.

These two chips were well received in the IoT market, powering a large number of connected devices. In the meantime, the IoT market itself has not only become mainstream, but it has also matured in terms of features and cost expectations. So, from now on, whenever defining a new product, Espressif understands that it has to strike a fine balance between features and cost. In fact, the company understands that the one-size-fits-all model is not viable, as there should be multiple products for various needs.

Hence, for simple and secure connectivity applications, Espressif introduced the ESP32-C3. It’s a Wi-Fi SoC (system-on-chip) that, despite its ESP32 name, contains a RISC-V core in place of the Tensilica core in the established ESP32 range, and uses the ESP8266 pin-out rather than that of its newer sibling.

The ESP32-C3 attempts to address the most common needs for connected devices. Here are the key criteria that have been considered in its design:

Security is of prime importance. Even the lowest-cost connectivity solution needs to provide an appropriate level of security for common security threats.

Bluetooth Low Energy availability is useful for improving user experience and field diagnostics.

While cost is a very important parameter, the availability of sufficient memory for common use cases is equally important. Optimising applications for memory utilisation, while maintaining such memory-constrained devices in the field, is challenging.

The ESP32-C3 is a single-core, 32-bit, RISC-V-based microcontroller with 400 KB of SRAM, which is capable of running at 160 MHz. It has integrated 2,4 GHz Wi-Fi and Bluetooth LE 5.0 with long-range support, as well as 22 programmable GPIOs with support for ADC, SPI, UART, I2C, I2S, RMT, TWAI, and PWM.