Introducing the ESP32-C3-based Smart Switch

Shanghai, China
Nov 22, 2021

This solution upgrades traditional switches to smart switches, without rewiring, or configuring a gateway. It also combines low power-consumption with reliable and secure Wi-Fi connectivity.

The present-day popularity of the Internet of Things has brought smart-home applications to the spotlight. Consumers’ attention has shifted towards an ever-increasing number of smart devices that can make people’s lives more comfortable. Espressif has been at the forefront of the IoT revolution, with our latest contribution being a smart switch based on the ESP32-C3 SoC. This solution upgrades traditional switches to smart switches, with no need for rewiring or configuring a gateway in the process. Espressif’s smart switch also combines low power-consumption with reliable and secure Wi-Fi connectivity.

Upgrading Your Switches with Ease

Many smart switches on the market often require a neutral wire, but most traditional switches in older houses do not include one. That’s why rewiring is the most common approach to replacing traditional switches with smart ones. However, Espressif’s smart switch does not need a neutral wire, which can help users greatly reduce their installment costs.

On a different note, due to the high power-consumption of most Wi-Fi chips, it is difficult to ensure that the power consumption of a smart switch is less than 50 uA, for example, when a lamp connected to the circuit is turned off; hence, an abnormal flickering of the lamp may occur. Therefore, most smart switches use Zigbee and Bluetooth LE networks which, however, require additional configurations. This increases the cost and complexity of such solutions, while also limiting, to a certain extent, the development of these smart switches any further. In response to this, Espressif has based its smart switch on ESP32-C3, which supports Wi-Fi and Bluetooth 5 (LE) connectivity, while also combining industry-leading radio frequency and low power-consumption, along with enhanced security features and memory resources. Based on the ESP32-C3, not only does Espressif’s smart switch solve the problems of high power-consumption and complex installation, but it also ensures secure data transmission and stable wireless performance across large areas, even with walls in between. Espressif’s smart switch enables new smart-home users to upgrade their traditional switches easily, effectively and at no extra cost.

Now, let’s delve into the advantages of Espressif’s smart switch:

1. Low Power-Consumption

To avoid flickering lights, it is especially important that users can control the power consumption of their smart switch. The ESP32-C3 SoC provides excellent service in this regard. With its advanced power-management technology, ESP32-C3 can easily switch between different power modes. Thus, Espressif’s smart switch achieves ultra-low power consumption, while maintaining a Wi-Fi connection, which is particularly useful for most lighting scenarios.

Advanced Power-Management Technology

ESP32-C3 uses Espressif’s IoT development framework, ESP-IDF. The power-management algorithm of ESP-IDF can dynamically adjust the frequency of the advanced peripheral bus (APB) and the central processing unit (CPU) to the needs of the application in use. By switching between different power modes, ESP32-C3 reduces the power consumption of the application to as low as 5 uA in deep-sleep mode.

Wi-Fi Optimization

ESP32-C3 optimizes the whole Wi-Fi protocol stack for Espressif’s smart switch.

      • Wi-Fi connection time: Both the RF calibration time and the Wi-Fi connection process are optimized, thus making the time from powering up the device to obtaining an IP address as little as 160 ms.
      • Power consumption of keep-alive Wi-Fi connections: The router’s beacon interval can be dynamically changed for the purpose of preventing packet losses and the subsequent increase of power consumption in complex network environments.

2. High Performance

Espressif’s ESP32-C3-based smart switch has an industry-leading RF performance, with the receiver sensitivity (RX) peaking at –98.4 dBm, and the transmit power (TX) reaching a high of 21 dBm. Such performance ensures a smooth and reliable Wi-Fi connection even when the device is installed in a wall. Furthermore, when two ESP32-C3 chips communicate with each other over a Wi-Fi connection, the maximum transmission distance between them can be up to 500 m in an open field, whereas in interior spaces the Wi-Fi signal can penetrate up to three walls and still cover a distance of 20 m, which fully meets the connectivity criteria of any smart-home application scenario.

Moreover, the versatility of ESP32-C3 makes Espressif’s smart switch compatible with a wide range of smart-home applications. ESP32-C3 supports the IEEE 802.11b/g/n protocols, along with the 20 MHz and 40 MHz bandwidth in the 2.4 GHz band. ESP32-C3 has also been granted several wireless RF certificates, including FCC, CE, and SRRC, which make Espressif’s smart switch compatible with various mainstream routers. ESP32-C3 automatically switches between IEEE 802.11b and IEEE 802.11g or IEEE 802.11n, depending on the network it is connected to. Users, then, are free to configure Wi-Fi parameters such as the interval between the Delivery of Traffic Indication Messages (DTIM), the transmit power, and the packet loss latency, according to network conditions.

3. Security and Reliability

The proliferation of smart devices poses a potential threat to data security, since connected IoT devices may be subject to malware attacks. Therefore, it is important that consumers choose a smart switch based on a secure and reliable chip. That’s why ESP32-C3 has a comprehensive security mechanism supporting secure boot based on the RSA-3072 algorithm, and flash encryption based on the AES-128-XTS algorithm. Such a mechanism ensures the firmware security of smart switches by running only those applications that have been specified by users themselves. The hardware accelerator of ESP32-C3, then, supports multiple encryption and decryption algorithms, thus protecting data transmission from malware attacks both on the local network and in the Cloud.

On top of this security mechanism, ESP32-C3 also ensures the reliability and stability of smart switches. The chip has a solid Wi-Fi performance at a temperature ranging from -40 °C to +105 °C, and has passed several reliability tests, including the High Temperature Operating Life (HTOL) test, the Electro-Static Discharge Sensitivity (ESD) test, and the Unbiased Highly Accelerated Stress Test (uHAST).

Facilitating the Development of Smart Switches

Espressif supports its customers in developing their own Wi-Fi smart switches, all the way from R&D to project implementation, by providing help with the hardware selection, circuit schematic design, example projects, software solutions, and mobile apps. Based on Espressif’s already mature IoT development framework, ESP-IDF, customers can easily build new applications or migrate existing ones to the ESP32-C3 platform.

The ESP32-C3 series of SoCs includes several variants which differ in terms of embedded flash, range of operating temperature, and package size. Each chip variant corresponds to certain modules, i.e., ESP32-C3 to ESP32-C3-WROOM-02/02U; ESP32-C3FN4 and ESP32-C3FH4 to ESP32-C3-MINI-1/1U; and finally ESP8685H2 to ESP8685-WROOM, as shown in the table below. Customers can choose the product that suits their project with the help of the ESP Product Selector.

ESP32-C3 SoC and Module Comparison

Espressif is constantly trying to expand its SoC portfolio. The newly-released ESP32-H2 comes with integrated IEEE 802.15.4 radio and Bluetooth 5 (LE) connectivity, while also supporting Matter, which is an industry-unifying, IP-based connectivity protocol. The capabilities of this SoC provide ample opportunities for new models of smart switches, among other innovative products, which we expect to enhance our impact on the AIoT industry, in general.

For more information about Espressif’s Wi-Fi smart-switch solution, please contact our customer support team, who will get back in touch with you as soon as possible.

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