The ESP8266 is a WiFi enabled System On a Chip (SOC) that's taken the design community by storm due to its low cost and wide availability (there are thousands of videos, tutorials, and examples for IoT projects that use the SOC online). The ESP8266 chip is made by a Chinese company called Espressif, which recently sent out beta units (called ESP31bs) of their new SOC, the ESP32. The ESP32 won’t be a replacement for the ESP8266, but a slightly more expensive and much more powerful SOC. Not all of the details have been announced yet, and some might change from the beta units, but let's take a look at what we know:
One of the 200 beta units distributed and one of the first projects made with ESP32 by Baoshi.
The biggest change with the ESP32 is the inclusion of Bluetooth capability. This will allow the ESP32 to be integrated into more projects so they're not limited to WiFi hot spots. The new chip will support classic Bluetooth and Bluetooth LE, which will make projects such as beacons and wearables possible.
Look at all that room for sensors
A major limitation with the ESP8266 was the lack of peripherals. Many people have groaned over the single 0-1v ADC or the lack of serial interfaces, but the ESP32 improves many of the ESP8266 limitations. These improved peripherals include:
- 10x Capacitive Touch Inputs
- 2x 8-Bit Digital to Analog Converters (DACs) 2x I2C, 4x SPI, and 2x UART Interfaces
- These will make it a lot easier to add lots of sensors
- 16x 12-Bit Analog to Digital Converters (ADC’s)
- No longer tied to just 0-1V
- Adjustable range up to 0-4v
Under the Hood
A layout of the ESP32
The ESP32 is far more powerful than the ESP8266, which is powered by a Tensilica CPU and clocked at 80MHz. The new ESP32 has dual Tensilica CPUs clocked at 160MHz. Having two CPUs allows one CPU to handle the processing required for the WiFi and Bluetooth, and the other CPU can be used for the user’s applications. In addition to the upgraded CPUs, the ESP32 also has more RAM on board with 416KB.
There is never a perfect solution for every user, and the ESP32 does have some limitations:
- External flash memory
- Just like the ESP8266, the new SOC will also need a separate IC for program and data storage.
- 3.3v logic
- The new SOC will also run on 3.3v logic, so depending on the application, a logic level converter and a 3.3v power supply may be needed.
Right now there are a few major unknowns with the ESP32: there has been no official pricing released yet for the ESP32, and there has been no official comment yet. The beta/demo units that were shipped were relatively polished, and a release date around late Q1 or early Q2 can be expected.
A major reason for the success of the ESP8266 was that the maker community got behind it. Will the maker community cling to the ESP32? With far more information and introductions on websites like Sparkfun, Adafruit, and Hackaday and a dedicated message board, success is looking quite likely.