330 lines
12 KiB
JavaScript
330 lines
12 KiB
JavaScript
/**
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* test_esp32_spice_ntc_bridge.mjs
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*
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* Advanced co-simulation: ESP32 reads a Wheatstone bridge with an NTC
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* thermistor through its ADC, and the bridge voltages are computed by
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* ngspice-WASM. The test sweeps temperature from 0C to 50C and verifies
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* the ESP32's calculated temperature matches within tolerance.
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*
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* Circuit (ngspice):
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* Vcc=3.3V
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* |
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* R1=10k R3=10k
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* | |
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* VA (ADC34) VB (ADC35)
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* | |
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* NTC(T) R4=10k (fixed reference)
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* | |
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* GND GND
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*
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* V_diff = VA - VB (proportional to NTC deviation from 10k)
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*
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* Sketch: reads ADC34 and ADC35, computes V_diff, estimates temperature
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* from the NTC beta-model, and prints via Serial.
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*
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* Run:
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* cd test/backend/e2e && npm install && node test_esp32_spice_ntc_bridge.mjs
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*
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* Prerequisites: Backend on http://localhost:8001, esp32 core installed.
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*/
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import { Simulation } from 'eecircuit-engine';
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const BACKEND = process.env.BACKEND_URL ?? 'http://localhost:8001';
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const WS_BASE = BACKEND.replace(/^https?:/, m => m === 'https:' ? 'wss:' : 'ws:');
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const SESSION = `test-esp32-ntc-${Date.now()}`;
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const TIMEOUT_S = parseInt(process.argv.find(a => a.startsWith('--timeout='))?.slice(10) ?? '120');
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// NTC beta model (matches the sketch)
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const NTC_R0 = 10000; // 10k at 25C
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const NTC_T0 = 298.15; // 25C in Kelvin
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const NTC_BETA = 3950;
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function ntcResistance(Tc) {
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const T = Tc + 273.15;
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return NTC_R0 * Math.exp(NTC_BETA * (1 / T - 1 / NTC_T0));
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}
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// ─── ESP32 Sketch ────────────────────────────────────────────────────────────
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const SKETCH = `// ESP32 Wheatstone bridge + NTC temperature reader
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// ADC34 = bridge leg A (NTC side)
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// ADC35 = bridge leg B (reference side)
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#define NTC_R0 10000.0
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#define NTC_T0 298.15
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#define NTC_BETA 3950.0
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#define R_PULL 10000.0
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#define VCC 3.3
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void setup() {
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Serial.begin(115200);
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analogReadResolution(12);
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delay(500);
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Serial.println("ESP32_BRIDGE_READY");
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}
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void loop() {
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int rawA = analogRead(34);
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int rawB = analogRead(35);
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float vA = rawA * VCC / 4095.0;
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float vB = rawB * VCC / 4095.0;
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// Estimate NTC resistance from VA (half-bridge: Vcc -> R_pull -> VA -> NTC -> GND)
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// VA = VCC * R_ntc / (R_pull + R_ntc) => R_ntc = R_pull * VA / (VCC - VA)
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float rNtc = R_PULL * vA / (VCC - vA + 0.001);
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// Beta model: T = 1 / (1/T0 + ln(R/R0)/beta)
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float tK = 1.0 / (1.0 / NTC_T0 + log(rNtc / NTC_R0) / NTC_BETA);
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float tC = tK - 273.15;
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Serial.printf("BRIDGE: rawA=%d rawB=%d vA=%.3f vB=%.3f R_ntc=%.0f T=%.1fC\\n",
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rawA, rawB, vA, vB, rNtc, tC);
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delay(500);
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}`;
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// ─── Logging ──────────────────────────────────────────────────────────────────
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const T0 = Date.now();
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const ts = () => `[+${((Date.now() - T0) / 1000).toFixed(3)}s]`;
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const C = { INFO: '\x1b[36m', OK: '\x1b[32m', ERROR: '\x1b[31m', SERIAL: '\x1b[32m', SPICE: '\x1b[35m', RESET: '\x1b[0m' };
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const log = (lvl, ...a) => console.log(`${C[lvl] ?? ''}${ts()} [${lvl}]${C.RESET}`, ...a);
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const info = (...a) => log('INFO', ...a);
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const ok = (...a) => log('OK', ...a);
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const err = (...a) => log('ERROR', ...a);
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const serial = (...a) => log('SERIAL', ...a);
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const spice = (...a) => log('SPICE', ...a);
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// ─── ngspice ──────────────────────────────────────────────────────────────────
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let engine = null;
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async function bootNgspice() {
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if (engine) return engine;
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spice('Booting ngspice-WASM...');
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engine = new Simulation();
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await engine.start();
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spice('ngspice ready');
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return engine;
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}
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async function solveBridge(tempC) {
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const rNtc = ntcResistance(tempC);
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const e = await bootNgspice();
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const netlist = `Wheatstone bridge T=${tempC}C
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V1 vcc 0 DC 3.3
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R1 vcc va 10k
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Rntc va 0 ${rNtc}
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R3 vcc vb 10k
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R4 vb 0 10k
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.op
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.end`;
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e.setNetList(netlist);
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const result = await e.runSim();
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const names = result.variableNames.map(n => n.toLowerCase());
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const iA = names.indexOf('v(va)');
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const iB = names.indexOf('v(vb)');
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if (iA < 0 || iB < 0) throw new Error(`Nets not found: ${names}`);
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const vA = result.data[iA].values[0];
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const vB = result.data[iB].values[0];
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spice(`T=${tempC}C: R_ntc=${rNtc.toFixed(0)} VA=${vA.toFixed(4)} VB=${vB.toFixed(4)}`);
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return { vA, vB, rNtc };
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}
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// ─── Compile ──────────────────────────────────────────────────────────────────
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async function compile() {
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info('Compiling ESP32 bridge sketch...');
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const res = await fetch(`${BACKEND}/api/compile/`, {
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method: 'POST',
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headers: { 'Content-Type': 'application/json' },
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body: JSON.stringify({
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files: [{ name: 'sketch.ino', content: SKETCH }],
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board_fqbn: 'esp32:esp32:esp32',
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}),
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});
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if (!res.ok) throw new Error(`Compile HTTP ${res.status}: ${(await res.text()).slice(0, 500)}`);
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const body = await res.json();
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if (!body.success) throw new Error(`Compile error: ${(body.error ?? body.stderr ?? '').slice(0, 500)}`);
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const fw = body.binary_content ?? body.firmware_b64;
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if (!fw) throw new Error(`No firmware. Keys: ${Object.keys(body)}`);
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ok(`Compiled -- ${Math.round(fw.length * 0.75 / 1024)} KB`);
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return fw;
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}
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// ─── Co-simulation ────────────────────────────────────────────────────────────
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function runCoSim(firmware_b64) {
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// Temperature sweep: 0C, 25C, 50C
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const temps = [0, 25, 50];
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return new Promise(async (resolve) => {
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// Pre-solve all circuits
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const circuits = {};
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for (const t of temps) {
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circuits[t] = await solveBridge(t);
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}
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const wsUrl = `${WS_BASE}/api/simulation/ws/${SESSION}`;
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info(`Connecting WebSocket -> ${wsUrl}`);
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const ws = new WebSocket(wsUrl);
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let lineBuf = '';
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let serialLines = [];
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let ready = false;
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let tempIdx = 0;
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let results = {}; // temp -> [{rawA, rawB, vA, vB, rNtc, tC}]
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let currentTemp = temps[0];
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const timer = setTimeout(() => {
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ws.close();
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resolve({ timedOut: true, results, serialLines, circuits });
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}, TIMEOUT_S * 1000);
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function injectVoltage(tempC) {
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const c = circuits[tempC];
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const mvA = Math.round(c.vA * 1000);
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const mvB = Math.round(c.vB * 1000);
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ws.send(JSON.stringify({ type: 'esp32_adc_set', data: { channel: 6, millivolts: mvA } }));
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ws.send(JSON.stringify({ type: 'esp32_adc_set', data: { channel: 7, millivolts: mvB } }));
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spice(`Injected T=${tempC}C: CH6=${mvA}mV CH7=${mvB}mV`);
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}
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ws.addEventListener('open', () => {
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ok('WebSocket connected');
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ws.send(JSON.stringify({
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type: 'start_esp32',
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data: { board: 'esp32', firmware_b64, wifi_enabled: false },
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}));
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});
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ws.addEventListener('message', ev => {
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let msg;
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try { msg = JSON.parse(ev.data); } catch { return; }
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if (msg.type === 'serial_output') {
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lineBuf += msg.data?.data ?? '';
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let nl;
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while ((nl = lineBuf.indexOf('\n')) !== -1) {
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const line = lineBuf.slice(0, nl).replace(/\r$/, '');
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lineBuf = lineBuf.slice(nl + 1);
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if (!line.trim()) continue;
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serialLines.push(line);
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serial(`UART: ${line}`);
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if (line.includes('ESP32_BRIDGE_READY') && !ready) {
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ready = true;
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ok('ESP32 bridge ready -- injecting first temperature');
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currentTemp = temps[0];
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injectVoltage(currentTemp);
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}
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const m = line.match(/BRIDGE:\s*rawA=(\d+)\s+rawB=(\d+)\s+vA=([\d.]+)\s+vB=([\d.]+)\s+R_ntc=([\d.]+)\s+T=([-\d.]+)C/);
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if (m) {
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const reading = {
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rawA: parseInt(m[1]), rawB: parseInt(m[2]),
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vA: parseFloat(m[3]), vB: parseFloat(m[4]),
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rNtc: parseFloat(m[5]), tC: parseFloat(m[6]),
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};
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if (!results[currentTemp]) results[currentTemp] = [];
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results[currentTemp].push(reading);
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// After 2 readings at this temp, move to next
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if (results[currentTemp].length >= 2) {
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tempIdx++;
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if (tempIdx < temps.length) {
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currentTemp = temps[tempIdx];
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info(`Switching to T=${currentTemp}C`);
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injectVoltage(currentTemp);
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} else {
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clearTimeout(timer);
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ws.close();
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resolve({ timedOut: false, results, serialLines, circuits });
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}
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}
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}
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}
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}
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if (msg.type === 'system') info(`system: ${JSON.stringify(msg.data)}`);
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if (msg.type === 'error') err(`error: ${JSON.stringify(msg.data)}`);
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});
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ws.addEventListener('error', e => err(`WS error: ${e.message ?? e}`));
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ws.addEventListener('close', () => {
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clearTimeout(timer);
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});
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});
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}
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// ─── Validation ───────────────────────────────────────────────────────────────
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function validate(result) {
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const { timedOut, results, circuits } = result;
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info('');
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info('══════════════════════════════════════════════════════════════');
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info(' Co-Simulation Results: ESP32 + ngspice Wheatstone Bridge');
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info('══════════════════════════════════════════════════════════════');
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let pass = true;
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if (timedOut) { err('Timed out'); pass = false; }
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for (const [tempStr, readings] of Object.entries(results)) {
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const temp = parseInt(tempStr);
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if (readings.length === 0) { err(`No readings for T=${temp}C`); pass = false; continue; }
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const avgT = readings.reduce((s, r) => s + r.tC, 0) / readings.length;
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const c = circuits[temp];
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info(`T=${temp}C: SPICE V(A)=${c.vA.toFixed(3)}V, R_ntc=${c.rNtc.toFixed(0)}ohm`);
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info(` ESP32 read: avgT=${avgT.toFixed(1)}C (${readings.length} samples)`);
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// Tolerance: +/- 5C (ADC quantization + beta model rounding)
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if (Math.abs(avgT - temp) > 5) {
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err(` Temperature off by ${Math.abs(avgT - temp).toFixed(1)}C (tolerance: 5C)`);
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pass = false;
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} else {
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ok(` Within tolerance`);
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}
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}
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// Check that different temperatures produce different readings
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const temps = Object.keys(results).map(Number).sort((a, b) => a - b);
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if (temps.length >= 2) {
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const first = results[temps[0]];
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const last = results[temps[temps.length - 1]];
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if (first?.length > 0 && last?.length > 0) {
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const delta = Math.abs(first[0].rawA - last[0].rawA);
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if (delta < 50) {
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err(`ADC readings too similar across temperatures (delta=${delta})`);
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pass = false;
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} else {
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ok(`Temperature sweep produces distinct ADC readings (delta=${delta})`);
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}
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}
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}
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info('');
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if (pass) {
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ok('ALL CHECKS PASSED -- ESP32 Wheatstone bridge + ngspice co-simulation works!');
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process.exit(0);
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} else {
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err('SOME CHECKS FAILED');
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process.exit(1);
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}
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}
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// ─── Main ─────────────────────────────────────────────────────────────────────
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async function main() {
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info('ESP32 + ngspice Wheatstone bridge co-simulation E2E test');
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info(`Backend: ${BACKEND} | Timeout: ${TIMEOUT_S}s`);
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info('');
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try {
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await bootNgspice();
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const firmware = await compile();
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const result = await runCoSim(firmware);
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validate(result);
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} catch (e) {
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err(`Fatal: ${e.message}`);
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if (e.message?.includes('fetch')) {
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err('Is the backend running? Start with: cd backend && uvicorn app.main:app --port 8001');
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}
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process.exit(1);
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}
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}
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main();
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