Created ESP32 app that scans local APs and reports signal strength.

src/main.rs

@@ -0,0 +1,49 @@
+use embedded_svc::wifi::{Configuration, ClientConfiguration};
+use esp_idf_svc::{wifi::EspWifi, eventloop::EspSystemEventLoop};
+use esp_idf_sys::{self as _, EspError}; // If using the `binstart` feature of `esp-idf-sys`, always keep this module imported
+use esp_idf_hal::prelude::Peripherals;
+
+fn main() -> Result<(), EspError> {
+    // It is necessary to call this function once. Otherwise some patches to the runtime
+    // implemented by esp-idf-sys might not link properly. See https://github.com/esp-rs/esp-idf-template/issues/71
+    esp_idf_sys::link_patches();
+    // Bind the log crate to the ESP Logging facilities
+    esp_idf_svc::log::EspLogger::initialize_default();
+
+    // Get Peripherals and sysloop ready
+    let sysloop = EspSystemEventLoop::take();
+    let peripherals = Peripherals::take().unwrap();
+    let modem = peripherals.modem;
+
+    // Enable WIFI Module
+    let mut wifi = EspWifi::new(modem, sysloop.clone()?, None)?;
+    wifi.set_configuration(&Configuration::Client(ClientConfiguration::default()))?;
+
+    wifi.start()?;
+
+    loop {
+        //Synchronously perform a scan and return nearby APs    
+        let ap_scan_res = wifi.scan()?;
+        println!("\n\n=======================================");
+        for net in ap_scan_res.into_iter().map(|ap| (ap.ssid, ap.signal_strength, rssi_to_percentage(ap.signal_strength))) {
+            println!("{}: {}dBm, {:.2}%", net.0, net.1, net.2);
+        }
+        println!("=======================================");
+    }
+}
+
+fn rssi_to_percentage(signal_strength: i8) -> f32 {
+    let max_i8 = std::u8::MAX as f32;
+    let percentage = (((signal_strength as f32) / max_i8) + 0.5) * 100.0;
+    percentage
+}
+
+mod tests {
+    #[cfg(test)]
+    #[test]
+    fn rssi_to_percentage_test() {
+        use super::rssi_to_percentage;
+        println!("{}", rssi_to_percentage(0));
+        assert_eq!(rssi_to_percentage(0), 50.0);
+    }
+}