diff --git a/README.md b/README.md
index e69de29..c76e293 100644
--- a/README.md
+++ b/README.md
@@ -0,0 +1,107 @@
+# Selsyn Gauge MQTT Controller
+
+MQTT-based gauge controller for ESP32 / MicroPython. Drives a VID28/BKA30D/X25 stepper gauge and integrates with Home Assistant via MQTT.
+
+## Files
+
+| File | Description |
+|------|-------------|
+| `boot.py` | WiFi connect + OTA trigger |
+| `ota.py` | Gitea API poller for OTA updates |
+| `gaugemqtt.py` | Main MQTT controller |
+| `gauge.py` | Stepper driver for VID28/BKA30D/X25 gauges |
+| `config.json` | Configuration (create from `config.example.json`) |
+| `config.example.json` | Template with all options |
+
+## Deployment
+
+```bash
+# First time: upload via USB
+ampy --port /dev/ttyUSB0 put boot.py
+ampy --port /dev/ttyUSB0 put ota.py
+ampy --port /dev/ttyUSB0 put gaugemqtt.py
+ampy --port /dev/ttyUSB0 put gauge.py
+ampy --port /dev/ttyUSB0 put config.json
+ampy --port /dev/ttyUSB0 put lib/gauge.py /lib/gauge.py
+
+# Monitor serial output
+minicom -D /dev/ttyUSB0 -b 115200
+```
+
+## MQTT Topics
+
+All topics are prefixed with `mqtt_prefix`:
+
+| Topic | Direction | Description |
+|-------|-----------|-------------|
+| `/set` | ← | Target value from HA |
+| `/state` | → | Current value |
+| `/status` | → | `online`/`offline` |
+| `/zero` | ← | Trigger zero calibration |
+| `/led/red/set` | ← | `ON`/`OFF` |
+| `/led/green/set` | ← | `ON`/`OFF` |
+| `/led/backlight/set` | ← | Brightness 0-100 |
+
+## Configuration
+
+Copy `config.example.json` to `config.json` and edit:
+
+### WiFi
+
+| Key | Default | Description |
+|-----|---------|-------------|
+| `wifi_ssid` | — | WiFi network name |
+| `wifi_password` | — | WiFi password |
+
+### MQTT
+
+| Key | Default | Description |
+|-----|---------|-------------|
+| `mqtt_broker` | — | Broker IP/hostname |
+| `mqtt_port` | 1883 | Broker port |
+| `mqtt_user` | — | MQTT username |
+| `mqtt_password` | — | MQTT password |
+| `mqtt_client_id` | — | Unique client ID |
+| `mqtt_prefix` | — | Topic prefix for all MQTT messages |
+
+### Gauge
+
+| Key | Default | Description |
+|-----|---------|-------------|
+| `gauge_pins` | `[12, 13, 26, 27]` | GPIO pins (IN1, IN2, IN3, IN4) |
+| `gauge_min` | 0 | Minimum value |
+| `gauge_max` | 7300 | Maximum value |
+| `gauge_pulse` | 4 | Pulse width in milliseconds |
+| `gauge_half_step` | false | Use 8-phase half-step mode (1200 steps, smoother) |
+| `smooth_step_ms` | 50 | Smooth movement interval |
+| `idle_release_ms` | 3000 | Release coils after idle (ms) |
+| `rezero_interval_ms` | 3600000 | Auto-rezero interval (ms, default 1hr) |
+
+### LEDs
+
+| Key | Default | Description |
+|-----|---------|-------------|
+| `led_red_pin` | 33 | Red LED GPIO pin |
+| `led_green_pin` | 32 | Green LED GPIO pin |
+| `led_bl_pin` | 23 | Backlight PWM GPIO pin |
+
+### Home Assistant Discovery
+
+| Key | Default | Description |
+|-----|---------|-------------|
+| `device_name` | "Selsyn 1" | Device name in HA |
+| `device_model` | "Chernobyl Selsyn-inspired gauge" | Device model |
+| `device_manufacturer` | "AdeBaumann" | Device manufacturer |
+| `device_area` | "Control Panels" | Suggested area in HA |
+| `gauge_entity_name` | "Selsyn 1 Power" | Gauge entity name |
+| `gauge_unit` | "W" | Unit of measurement for gauge |
+| `red_led_entity_name` | "Selsyn 1 Red LED" | Red LED entity name |
+| `green_led_entity_name` | "Selsyn 1 Green LED" | Green LED entity name |
+| `backlight_entity_name` | "Selsyn 1 Backlight" | Backlight entity name |
+| `backlight_unit` | "%" | Unit for backlight |
+
+### Timing
+
+| Key | Default | Description |
+|-----|---------|-------------|
+| `heartbeat_ms` | 10000 | State publish interval (ms) |
diff --git a/ota.py b/ota.py
index 7a36313..46fde72 100644
--- a/ota.py
+++ b/ota.py
@@ -87,6 +87,16 @@ def info(msg):    _log("INFO",  msg)
 def warn(msg):    _log("WARN",  msg)
 def log_err(msg): _log("ERROR", msg)
 
+# ---------------------------------------------------------------------------
+# HTTP helpers
+# ---------------------------------------------------------------------------
+
+def _headers():
+    h = {"Accept": "application/json"}
+    if API_TOKEN:
+        h["Authorization"] = f"token {API_TOKEN}"
+    return h
+
 # ---------------------------------------------------------------------------
 # Config loader
 # ---------------------------------------------------------------------------