Learn how ESP8266 and ESP32 WiFi modules are used to integrate IoT capabilities and how ESP32-C3 adds another option.
Espressif Revolutionized IoT Integration
By Jeremy Cook
Back in the old days, 5-10 years ago, a toaster was just a toaster. Your washing machine wouldn't text to let you know a load was complete, and existing home automation consisted of a hodgepodge of different protocols and hacks. While listening for a laundry buzzer is still the norm, and you're going to occasionally burn your toast, enhancing a device with wireless control and intelligently connected operation has become much easier, thanks to ESPRESSIF SYSTEMS' series of ESP WiFi chips.
ESP8266 Revolutionizes Embedded WiFi, ESP32 Provides Enhanced Capabilities
The ESP8266 first gained widespread notoriety in 2014 with the ESP-01 WiFi adapter module. This tiny and wondrous device allowed microcontrollers to communicate over WiFi. After more development, it was found that the ESP8266 could be used as a competent controller by itself. This spawned a variety of breakout boards, and the device is now integrated into a wide range of off-the-shelf devices that form much of the Internet of Things.
So prevalent is this chipset that if you have a smart device, there's a good chance it's some variety of the ESP8266 module onboard, or its offspring, the ESP32. As outlined here, if you're not happy with such a device's operation, you can even flash alternative Tasmota software on it for control.
The ESP32, for its part, premiered in 2016 and features several improvements over the ESP8266, including the ability to communicate via WiFi and Bluetooth 4.2, and BLE. The ESP32 features up to 32 GPIO pins versus the ESP8266 (up to 17), along with dual-core processing, capacitive touch capabilities, a temperature sensor, and a Hall effect sensor.
In defense of the ESP8266, it tends to be a bit less expensive, though both are quite reasonable when compared to what it would have taken to build a connected device not too long ago. Additionally, there was more support available for the ESP8266 just after the '32 premiered. Depending on the IoT device in question, the ESP8266 may have been the right choice for a project at the time.
ESP32-C3: The Best of Both Worlds?
Not a company to rest on its laurels, ESPRESSIF debuted the ESP32-C3 in 2020, bridging the gaps between the '8266 and '32 worlds. This new chip is a significant improvement over the ESP8266 but omits a few features of the ESP32. Notably, the ESP32-C3 module is pin-compatible with the ESP8266, making it appropriate not only for new designs but it could serve as a nice drop-in upgrade for existing boards as well.
The ESP32-C3 has 22 GPIO pins, putting it right between the capabilities of the ESP32 and ESP8266. It features Bluetooth 5.0 and BLE along with WiFi capabilities. It eschews a dual-core processor in favor of an RISC-V architecture chip, which is nice to see more frequently in the wild. It also features an RTC module (as does the ESP32, not the ESP8266) though it doesn't have the touch sensing capabilities or the Hall effect sensor of the ESP32. So, in some applications, the ESP32 may still be the right choice. However, the ESP32-C3 would most likely be preferable over the ESP8266.
Another option that we haven't discussed is the ESP32-S2, which appeared in 2019, and offers enhanced features over the standard ESP32, including 43 GPIO pins. It doesn't feature Bluetooth, which could be an issue, nor does it have a Hall effect sensor.
Whichever option you choose, it's staggering just how much power and connectivity can fit into one of these tiny modules!