We went over different Micro-controller options to create each of mesh nodes and some of them offer on-board Wi-Fi and Bluetooth chip-set but there could be a need to extend the Wi-Fi range.We will compare different antenna options in this update.

Omega2 and WiPy 2.0 both have UFL Connector and their Wi-Fi range can be extended by adding an external antenna.

https://www.adafruit.com/product/3340

Raspberry Pi Zero W and other versions of Raspberry Pi offer the option to extend Wi-Fi range by adding an external Wi-Fi USB dongle.

USB WiFi (802.11b/g/n) with RTL8192cu Chip-set and Ralink RT3070 Chipset work out of the box with Raspbian OS and they are the two of the most common USB Wi-Fi dongles which can be purchased in most countries.

https://www.adafruit.com/product/1030

https://www.modmypi.com/raspberry-pi/accessories/wifi-dongles/wifi-dongle-ultra-long-range-high-gain-w-5dbi-antenna

We will be looking at more options in future posts and make final decision.