The addition of wireless and Bluetooth to the Raspberry Pi 3 has piqued our interest in IoT devices, but what about the Pi Zero? The smallest board in the Raspberry Pi range is ideal for low-cost IoT builds, but it doesn't feature built-in wireless.
While it’s tempting to think of the ESP8266 IOT pHAT as WiFi for your Raspberry Pi Zero, this is a mistake, or at the very least an understatement. Sure, it can add WiFi to your Pi Zero, but if all you want to do is head online, you’re much better off using a USB WiFi dongle.
The ESP8266 IOT pHAT is a way to get started with ESP8266, an extremely low-cost WiFi chip with a full TCP/IP stack and SoC (system on chip). ESP8266 was created by Chinese-based Espressif Systems, and hackers quickly realised it would be incredibly useful (and cheap) for building IoT devices. Hackaday’s Richard Baguley explains: “[It] can connect to 802.11b/g/n networks on the 2.4GHz band. It can be addressed with SPI or a serial connection, and has an AT command set that makes it behave rather like an old‑style modem. It has everything you would need to connect a device to a WiFi network.”
A wireless Zero
The chip itself came out in late 2014 and, during 2015, Western IoT enthusiasts translated its datasheets into English. Pimoroni has taken the ESP8266 and turned it into a HAT-like board, enabling you to combine the processing power of the Raspberry Pi with the wireless capabilities of the ESP8266.
Setup is moderately complex, and you’ll need to solder the pins to the board. If you haven't done so already, you’ll also need to solder the GPIO header to the Raspberry Pi Zero. Both are quite fiddly tasks, although we found soldering the pHAT easier than the Pi Zero. But it’s still a job for confident solderers.
The community has done a fabulous job of translating the ESP8266 dataset from Chinese, but it’s still a complex and niche area. IoT enthusiasts should certainly take a closer look.
The ESP8266 is an attractive chip, and the combination of robust TCP/IP communication and Raspberry Pi power is a compelling one. One for serious IoT project makers.