#include #include const char* ssid = "OPPO A15s"; const char* password = "987654321v"; ESP8266WebServer server(80); /* ---------- HARDWARE ---------- */ const int pwmPin = 4; // GPIO4 (D2) const int PWM_MAX = 261; /* ---------- CALIBRATION ---------- */ float CAL_SLOPE = 0.00885; // A per PWM (TWEAK THIS) /* ---------- STATE ---------- */ bool loadEnabled = false; float setCurrentA = 0.0; int pwmValue = 0; /* ---------- APPLY PWM ---------- */ void applyLoad() { if (!loadEnabled) { pwmValue = 0; } else { pwmValue = (int)(setCurrentA / CAL_SLOPE); pwmValue = constrain(pwmValue, 0, PWM_MAX); } analogWrite(pwmPin, pwmValue); } /* ---------- WEB PAGE ---------- */ String webPage() { String html = R"rawliteral(

ELECTRONIC LOAD V3

Status: OFF

Set Current: 0.00 A

)rawliteral"; return html; } /* ---------- HANDLERS ---------- */ void handleRoot() { server.send(200, "text/html", webPage()); } void handleSet() { if (server.hasArg("i")) { setCurrentA = server.arg("i").toFloat(); setCurrentA = constrain(setCurrentA, 0.0, 2.3); applyLoad(); } server.send(200, "text/plain", "OK"); } void handleToggle() { loadEnabled = !loadEnabled; applyLoad(); server.send(200, "text/plain", "OK"); } void handleState() { String json = "{"; json += "\"current\":" + String(setCurrentA, 3) + ","; json += "\"on\":" + String(loadEnabled ? "true" : "false") + ","; json += "\"pwm\":" + String(pwmValue); json += "}"; server.send(200, "application/json", json); } /* ---------- SETUP ---------- */ void setup() { Serial.begin(115200); pinMode(pwmPin, OUTPUT); analogWrite(pwmPin, 0); WiFi.begin(ssid, password); while (WiFi.status() != WL_CONNECTED) delay(300); server.on("/", handleRoot); server.on("/set", handleSet); server.on("/toggle", handleToggle); server.on("/state", handleState); server.begin(); } /* ---------- LOOP ---------- */ void loop() { server.handleClient(); }