Device Configuration

Device configuration

The Device Configuration page defines external I²C hardware that DCC-EX creates during EX-CSB1 startup. The configuration is stored in LittleFS as /devices.json, included in Export/Import backups, and restored before browser clients begin controlling the layout.

Supported dynamic devices in alpha6:

Device	Channels	Typical I²C range	Purpose
PCA9685	16	0x40–0x7F	PWM and servo outputs
MCP23017	16	0x20–0x27	Digital inputs and outputs
PCF8574	8	0x20–0x27	Digital inputs and outputs
PCF8575	16	0x20–0x27	Digital inputs and outputs

Device list and status

Select a device in the left list to open its pins in the wider right panel. The page shows:

• the I²C address and allocated VPIN range;
• configuration enabled/disabled state;
• WebSocket connection state;
• live HAL online/offline state from the firmware;
• unsaved changes that require Apply & restart.

Use the scan button to list currently detected I²C addresses. A saved device may be valid but offline when its address is not detected, wiring is incorrect, or the board has no power.

PCA9685 channels

Each channel has independently saved:

• OFF position and ON position from 0 to 4095;
• movement time in milliseconds;
• Keep PWM active after movement;
• manual OFF and ON test buttons.

Testing uses the configured analog servo endpoints rather than a Boolean VPIN command. Save and restart after changing channel configuration before relying on the test result.

When Signal Logic is enabled, the page displays a warning. Automation may legitimately write the same VPIN immediately after a manual test and therefore appear to switch the output back.

Digital input pins

Choose Input / DCC-EX sensor, then assign a unique Sensor ID. At boot the firmware creates the equivalent of:

<S SENSOR_ID VPIN PULLUP>

MCP23017 inputs can enable their internal pull-up. PCF8574 and PCF8575 inputs use the device's weak pull-up behavior.

The pin card displays a live state badge:

• ACTIVE — DCC-EX reported <Q SENSOR_ID>;
• INACTIVE — DCC-EX reported <q SENSOR_ID>;
• UNKNOWN — no state has been received yet or WebSocket is disconnected.

Sensor states are cached by the firmware as compact 16-bit groups. A new or refreshed client receives one bounded snapshot, then individual sensorChanged events. This keeps the layout, mobile overlay, and Device Configuration page synchronized.

Digital output pins

Choose Output / DCC-EX output, assign a unique Output ID, and configure inversion and initial state. The firmware creates the output during boot and the page tests it with:

<Z OUTPUT_ID 0>
<Z OUTPUT_ID 1>

Applying changes safely

The firmware validates I²C address conflicts, VPIN overlaps, duplicate sensor/output IDs, channel ranges, and driver-specific settings. Apply & restart saves the document atomically and restarts the EX-CSB1 so HAL devices are built in a predictable order.

Before applying:

1. turn track power off if outputs can move physical hardware;
2. create an Export/Import backup;
3. verify I²C addresses and non-overlapping VPIN ranges;
4. remember that changing an ID can invalidate layout or Signal Logic references.