⚙️ 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 the Cloud app — 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.

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🟢🟠 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 the Cloud app (for example, ENABLE_OUTPUTS is true only if an effect has a pin assigned) — see Deploy to Devices. If no generated config.h exists yet, the firmware falls back to config.default.h, which ships with every flag below set to false.

🪛 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)

🔧 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 the Cloud app:

#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

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🛜 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 MQTT credentials in at build time. The deja deploy wizard prompts for these and writes them in via generateEsp32WifiConfig().

📶 WiFi Settings

📬 MQTT Settings

🏷️ 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.

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

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🍓 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.

{
  "pins": {
    "6": "GP6",
    "7": "GP7",
    "8": "GP8",
    "9": "GP9"
  }
}

Keys are the logical pin numbers used in commands ("pin": 8). Values are CircuitPython GPIO names ("GP8").

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