Since the ESP8266 was released, over four years ago now, there have been a number of possible competitors like the RTL8710 or, more recently, the RDA5981. But none of them have really taken off in the same way as the Espressif chip did. Often with a price point higher than the ESP8266 itself, but with roughly similar performance, the community that formed around the ESP8266 and the ESP32 chips has seen little reason to switch to a new platform. The ESP8266 is seen by most as being “good enough.”
That doesn’t stop people from releasing new hardware of course, and the latest to make it to market is the Air602 module available from SeeedStudio.
Based around the WinnerMicro W600, an Arm Cortex-M3 with 1MB of Flash on chip with 2.4GHz WiFi support, the Air602 module has a tiny 10×12 mm footprint—less than half the size of the ESP-01 which measures 24.8 × 14.3 mm—although this is partially due to the fact that the module has no on-board antenna or antenna socket.
The W600 has dual UARTs, I2C, SPI and I2S interfaces, as well as RTC and hardware cryptography support. However the Air602 module has limited pin outs, offering 12 pins. But with two of these dedicated to ground pins, one to +3.3V power, one to the antenna, and one reset pin, that leaves only seven available for I/O. These are split between the two UARTs—with SPI available as a secondary option—and a single GPIO pin.
While limited, this is notably still more than the highly constrained ESP-01 module which made the ESP8266 such a success. So perhaps, given the price point it is more than good enough?
The board provides the missing antenna in the form of an on-board PCB antenna, and USB connectivity, however pin availability is even more constrained. With one of the two UART connections taken for the USB only 5 pins are broken out by the board. Which admittedly is still better than the ESP-01 breakout, and a lot easier to manage when it comes to the wiring.
The real sticking point for the board is, like in the early days of the ESP8266, the development tool chain. The module ships with a Luat firmware, which combines Lua and AT commands. But documentation is almost as sparse as the early days of the ESP8266, and again mostly in Chinese, so when you compare it to the now maturing development environment of the ESP8266 it comes up rather short.
The real advantage I see here for the Air602 is that, unlike the ESP8266 which is based around a Xtensa core, the W600 chip at the heart of the Air602 is an Arm processor. While possibly making the module more attractive to startups building Internet of Things products, I’m not sure that’s going to be enough to topple the “third community” of the maker electronics world.
At least right at the moment it seems that SeeedStudio is the only easily accessible outlet carrying the new modules. However, while I haven’t been able to find them for sale on AliExpress or Alibaba, if you’re proficient in sourcing parts on Taobao, then you can pick up the Air602 module or even development board for just $1 on the Chinese facing site. Which makes the Air602 not just price competitive with the ESP8266, but the first competitor to actually retail cheaper than the Espressif modules. Computing has reached a point where it is almost cheap enough to throw away.
Although if you’re not sure you want to face negotiating Taobao, you can still pick up an Air602 module for $1.90 per piece from SeeedStudio, and the Air602 development board, which has both integrated USB and an on-board antenna for $2.90 per piece.