1 files changed, 147 insertions, 0 deletions
diff --git a/firmware/wifi_analyzer.cpp b/firmware/wifi_analyzer.cpp
new file mode 100644
index 0000000..0264088
--- /dev/null
+++ b/firmware/wifi_analyzer.cpp
@@ -0,0 +1,147 @@
+#include <Arduino.h>
+#include <WiFi.h>
+#include <esp_wifi.h>
+
+#include "display.h"
+#include "buttons.h"
+
+// ===== CONFIG =====
+#define GRAPH_WIDTH     128
+#define GRAPH_HEIGHT    44
+#define GRAPH_TOP       10
+#define MAX_POINTS      128
+#define SPIKE_THRESHOLD 30
+
+// ===== STATE =====
+struct SnifferGraph {
+    uint8_t graphData[MAX_POINTS];
+    uint8_t currentChannel = 1;
+    volatile uint16_t packetCounter = 0;
+    unsigned long lastChannelSwitch = 0;
+    unsigned long lastUpdate = 0;
+};
+
+static SnifferGraph sniffer;
+
+// ===== CALLBACK =====
+void IRAM_ATTR snifferCallback(void *buf, wifi_promiscuous_pkt_type_t type)
+{
+    if (type == WIFI_PKT_MGMT || type == WIFI_PKT_DATA || type == WIFI_PKT_CTRL)
+    {
+        sniffer.packetCounter++;
+    }
+}
+
+// ===== INIT =====
+void wifi_analyzer_start()
+{
+    // display init (safe to call again)
+    u8g2.clearBuffer();
+    u8g2.setFont(u8g2_font_5x8_tr);
+    u8g2.drawStr(0, 10, "Starting analyzer...");
+    u8g2.sendBuffer();
+
+    // reset graph
+    memset(sniffer.graphData, 0, sizeof(sniffer.graphData));
+    sniffer.packetCounter = 0;
+    sniffer.currentChannel = 1;
+
+    // reset WiFi
+    WiFi.disconnect(true, true);
+    esp_wifi_stop();
+    delay(200);
+    esp_wifi_deinit();
+
+    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
+    esp_wifi_init(&cfg);
+    esp_wifi_set_storage(WIFI_STORAGE_RAM);
+    esp_wifi_set_mode(WIFI_MODE_NULL);
+    esp_wifi_start();
+
+    esp_wifi_set_channel(sniffer.currentChannel, WIFI_SECOND_CHAN_NONE);
+    esp_wifi_set_promiscuous_rx_cb(snifferCallback);
+    esp_wifi_set_promiscuous(true);
+}
+
+// ===== HELPERS =====
+static void switchChannel()
+{
+    sniffer.currentChannel++;
+    if (sniffer.currentChannel > 13) sniffer.currentChannel = 1;
+
+    esp_wifi_set_channel(sniffer.currentChannel, WIFI_SECOND_CHAN_NONE);
+}
+
+static void updateGraph(uint8_t value)
+{
+    for (int i = 0; i < MAX_POINTS - 1; i++)
+    {
+        sniffer.graphData[i] = sniffer.graphData[i + 1];
+    }
+
+    sniffer.graphData[MAX_POINTS - 1] = value;
+}
+
+static void drawGraph(uint16_t pktCount)
+{
+    u8g2.clearBuffer();
+    u8g2.setFont(u8g2_font_5x8_tr);
+
+    char line1[16];
+    char line2[16];
+
+    sprintf(line1, "Ch:%d", sniffer.currentChannel);
+    sprintf(line2, "Pkts:%d", pktCount * 5);
+
+    u8g2.drawStr(0, 8, line1);
+    u8g2.drawStr(60, 8, line2);
+
+    for (int x = 1; x < GRAPH_WIDTH; x++)
+    {
+        int y1 = GRAPH_TOP + GRAPH_HEIGHT - sniffer.graphData[x - 1];
+        int y2 = GRAPH_TOP + GRAPH_HEIGHT - sniffer.graphData[x];
+
+        u8g2.drawLine(x - 1, y1, x, y2);
+    }
+
+    if (pktCount >= SPIKE_THRESHOLD)
+    {
+        u8g2.drawVLine(GRAPH_WIDTH / 2, GRAPH_TOP, GRAPH_HEIGHT);
+    }
+
+    u8g2.sendBuffer();
+}
+
+// ===== LOOP =====
+void wifi_analyzer_loop()
+{
+    static uint32_t lastPress = 0;
+    unsigned long now = millis();
+
+    // channel hopping
+    if (now - sniffer.lastChannelSwitch >= 1000)
+    {
+        sniffer.lastChannelSwitch = now;
+        switchChannel();
+    }
+
+    // graph update
+    if (now - sniffer.lastUpdate >= 200)
+    {
+        sniffer.lastUpdate = now;
+
+        uint16_t pktCount = sniffer.packetCounter;
+
+        uint8_t scaled = pktCount * 2;
+        uint8_t value = min(scaled, (uint8_t)GRAPH_HEIGHT);
+
+        updateGraph(value);
+        drawGraph(pktCount);
+
+        sniffer.packetCounter = 0;
+    }
+
+    // optional: small debounce to not hammer CPU
+    if (millis() - lastPress < 10)
+        return;
+}