Chen Liang Turns Any Espressif ESP32-C5 and a Display Into a Compact Dual-Band Wi-Fi Analyzer
Simple two-component build — plus a battery, if you want it portable — provides real-time monitoring of Wi-Fi congestion.
Maker Chen Liang has taken full advantage of the dual-band nature of the Espressif ESP32-C5 wireless system-on-chip to build a compact Wi-Fi channel analyzer covering both the 2.4GHz and 5GHz spectra — and you only need two components, plus power.
"Wi-Fi Analyzer is a handy [smartphone] app that help to visualize the Wi-Fi signal information around you," Liang explains. "It is very useful for helping select a right channel for setting [up] a new AP [Access Point]. If you selected a channel that overlaps with other AP near you, you may encounter interference and degrade the network performance. If you want continuous monitoring, dedicat[ing] a mobile phone or notebook for Wi-Fi scanning is a little bit overkill. A Wi-Fi dev board with display is more cost effective for this job."
Liang is no stranger to the concept, having already used Espressif's earlier ESP8266 to build a standalone Wi-Fi analyzer — taking signal strength readings for detected access points and mapping them to a chart that provides at-a-glance information about the least-congested channels in the area. The Espressif ESP8266, though, has a Wi-Fi radio limited to the 2.4GHz band — unlike the newer and considerably more powerful ESP32-C5, which can cover the 5GHz band too.
Liang's build has only two components: "any ESP32-C5 dev board," he explains, plus any display supported by the Arduino_GFX graphics library. The only other parts you need are wires to join the two plus some way of powering everything — USB working just fine, though many ESP32-C5 boards include support for lithium battery power if you're looking to make the project portable.
"In my scan area," Liang says of his findings, "the number of 5G[Hz] Wi-Fi AP[s] is even more than 2.4G Wi-Fi AP[s]. But since 5G[Hz] Wi-Fi signal [is] significantly weakened after pass[ing] through walls if compare[d] with 2.4G[Hz] Wi-Fi, most signal[s are] lower than -70dB. So 5G[Hz] WiFi should encounter lesser interference with other AP nearby. Furthermore, 5G[Hz] Wi-Fi have more channel[s] available and wider bandwidth, [so] it is a good option for small area high speed connection."
The project is documented in full on Instructables.
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