What is IoT pHAT?

IoT (Internet-of-Things) 
HAT (Hardware Attached on Top)

It is an add-on board that provides Wi-Fi and Bluetooth connectivity for the Raspberry Pi.

You can use Wi-Fi and Bluetooth USB dongles, however .......

IoT pHAT is more affordable

You get both functions for the price of one dongle. And if you are using Pi Zero, you may also need to purchase:

• USB OTG cable ($3-$5) - connect a normal USB device to the Pi Zero's micro USB port.
• USB hub with power adapter ($15-$30) - if you need to connect more than one USB device, it is advisable to use a powered hub for your Wi-Fi and/or USB Bluetooth dongle(s). 

The setup is more orderly

Because you do not need the USB OTG Cable and the USB Hub etc, the setup is faster and looks less cluttered.

If you are running an IoT project, you could also remove the keyboard and mouse.

IoT pHAT has the same wireless radio as the Pi 3

Using the same BCM43438 chip that is on the Pi 3 (read here) which supports both Wi-Fi 802.11n (2.4GHz) + Bluetooth 4.1 (Dual Mode – Classic and Bluetooth Low Energy) running at the same time.

The wireless radio of IoT pHAT is as good as that of the Pi 3 and all WiFi/Bluetooth software for Pi 3 are compatible.

You can extend the RF range easily

The IoT pHAT has an on-board antenna. However if you want to increase the RF range, you can simply attach a compatible antenna to the external antenna socket and flip a switch. No hacking or soldering is required.

Both Wi-Fi and Bluetooth operate on the same 2.4GHz frequency, they share the on-board antenna or an external antenna when running.

Pi Zero + IoT pHAT is the best IoT combo

Not only is the combination the cheapest of all the options, it has also has the lowest power consumption!

You can connect to your Pi over the Internet easily with Weaved's IoT Kit for the Raspberry Pi. 

Technical details

Layout

Dimensions

IoT pHAT is designed to fit perfectly on the Pi Zero, measuring 65 x 30 mm.

And it is also compatible with all previous Pi models with the 40-pins connector including Pi 2, model A+ and B+.

Pinout

After connecting the IoT pHAT, there are 11 GPIO pins left for you to use.