⚙️ Configuration Reference

DEJA IO devices use different configuration formats depending on the device type and transport. This reference covers all of them.

deja deploy generates all of these automatically from your device's configuration in Throttle — you shouldn't normally need to hand-edit them. This reference is here for when you want to understand (or manually tweak) what got generated.

---

🟢🟠 Arduino & ESP32 USB — config.h

Compile-time configuration shared by deja-arduino and deja-esp32. The Arduino firmware reads these values at build time.

🚦 Feature Flags

deja deploy computes each flag from what's actually configured on the device in Throttle (for example, ENABLE_OUTPUTS is true only if an effect has a pin assigned) — see Deploy to Devices. A generated config.h starts with #define DEJA_BAKED 1, which tells the firmware to use the values on this page.

If there is no config.h, the sketch builds from config.default.h instead. That is the generic image the browser installer flashes: it has no pins of its own and drives nothing until the installer writes the device's config into it.

🧓 Arduino IDE users with an older config.h: a hand-kept config.h from before DEJA_BAKED existed still works. Because it defines DEVICE_ID, the firmware treats it as baked and builds exactly as before. Regenerating it is optional.

🪛 Pin Arrays

int OUTPINS[] = {8, 9, 10, 11};       // Digital output GPIO pins
int SIGNALPINS[] = {4, 5, 6, 7};      // Signal head GPIO pins
int SENSORPINS[] = {A0, A1, A2};      // Sensor input pins (analog or digital)
int SENSORMODES[] = {};               // INPUT or INPUT_PULLUP, parallel to SENSORPINS

🔧 Turnout Definitions

TurnoutPulser turnouts[] = {
  TurnoutPulser(channel, closedAngle, thrownAngle),
};

• channel — PCA9685 servo channel (0–15)
• closedAngle — servo angle for closed position (degrees)
• thrownAngle — servo angle for thrown position (degrees)

🎛️ PCA9685 Wiring & Timing

Present when ENABLE_PWM is on, generated from your device's PCA9685 wiring in Throttle:

#define PCA9685_SDA_PIN 21
#define PCA9685_SCL_PIN 22
#define PWM_OSCILLATOR_FREQ 27000000L

• PCA9685_SDA_PIN / PCA9685_SCL_PIN — I2C pins the PCA9685 board is wired to
• PWM_OSCILLATOR_FREQ — the PCA9685's internal oscillator frequency, used to calibrate servo pulse timing

---

🛜 ESP32 WiFi — config.h

Compile-time configuration for deja-esp32-wifi. The sketch lives at io/src/deja-esp32-wifi/. Unlike the Pico W (which reads settings.toml at runtime), the ESP32 WiFi firmware bakes WiFi and transport settings in at build time. The deja deploy wizard prompts for WiFi plus the MQTT broker or, for WebSocket devices, the DEJA server host and port, and writes them in via generateEsp32WifiConfig().

📶 WiFi Settings

🔌 Transport

📬 MQTT Settings (DEJA_TRANSPORT_WS 0)

🔌 WebSocket Settings (DEJA_TRANSPORT_WS 1)

🏷️ Device Identity

🚦 Feature Flags & Pin Arrays

ENABLE_PWM / ENABLE_OUTPUTS / ENABLE_SIGNALS / ENABLE_SENSORS / ENABLE_TURNOUTS and the OUTPINS / SIGNALPINS / SENSORPINS / TurnoutPulser definitions all use the same semantics as the deja-arduino config above.

SENSOR_DEBOUNCE_MS (default 500) sets the minimum time between sensor state changes.

🛜 If you change WiFi, MQTT or WebSocket settings, you have to re-flash the device — the values are compiled in.

---

🍓 Pico W — settings.toml

Runtime environment configuration for deja-mqtt. Loaded by CircuitPython at boot.

🍓 Pico W — config.json

Pin mapping from logical pin numbers to physical CircuitPython GPIO names, plus the device's Kato turnouts and sensors.

{
  "pins": {
    "6": "GP6",
    "7": "GP7",
    "8": "GP8",
    "9": "GP9"
  },
  "turnouts": [
    { "index": 0, "straight": "GP14", "divergent": "GP15", "pulseMs": 250 }
  ],
  "sensors": [
    { "index": 0, "pin": "GP20", "debounceMs": 100 }
  ]
}

• pins — keys are the logical pin numbers used in commands ("pin": 8); values are CircuitPython GPIO names ("GP8").
• turnouts — Kato turnouts, addressed by position in turnout commands. state: false pulses straight, true pulses divergent, for pulseMs.
• sensors — inputs reported as { "device", "sensor": index, "state" } on each change; debounceMs (default 100) is the minimum time between two reported changes of the same sensor, not a hold time.

---