Table of Contents
er-01-rev-a
Universal I/O module for the Wonder Controlz escape room system. Connects to the CAN bus and provides PWM outputs, digital inputs, servo outputs, and USB HID host — all controlled remotely from Node-RED on the Main PC.
The module contains no game logic. It executes commands received over CAN and reports input state changes back. This means a failed unit can be replaced in minutes — plug in a new one, set the CAN address with buttons, and it works immediately.
Status: Production (actively deployed in escape rooms).
Successor: er-dio-01 (in development).
Power
Input supply is 24V DC via the CAN bus cable (4 wires: 24V, GND, CAN_H, CAN_L).
The module has built-in DC-DC converters that produce 12V and 5V internally:
| Rail | Max Current | Used for |
|---|---|---|
| 24V | pass-through | Available on dedicated output connector |
| 12V | 4 A | PWM outputs (default) |
| 5V | 4 A | USB port, servo connectors, dedicated 5V output |
Idle power consumption: < 0.7 W.
PWM Outputs (×8)
Low-side switching via N-channel MOSFETs (switched ground).
| Parameter | Value |
|---|---|
| Channels | 8 |
| Max current per channel | 2.5 A |
| Total current (all channels) | 4 A (limited by 12V converter) |
| PWM resolution | 0–1000 (smooth dimming, motor speed control) |
Voltage flexibility: Since the outputs switch the ground side, the positive supply can be 5V, 12V, or 24V — depending on what the connected device needs. One module can control devices at different voltages.
Protection:
- Thermal overcurrent protection on each MOSFET
- Flyback clamping diodes (up to 100 mJ) — safe for inductive loads such as electromagnetic locks
Digital Inputs (×8)
Dry-contact (potential-free) inputs for sensors and switches.
| Parameter | Value |
|---|---|
| Channels | 8 |
| Type | Dry contact (active LOW) |
| Debounce | Hardware RC filter, ~10 ms (PLC-grade) |
| Current through closed contact | < 4 mA |
Compatible sensors: reed switches, pushbuttons, limit switches, PIR sensors (dry contact output), Hall sensors, relay contacts.
State changes are reported to the Main PC automatically over CAN.
Servo Outputs (×16)
Standard RC servo outputs with smooth motion profiles.
| Parameter | Value |
|---|---|
| Channels | 16 (two 8-channel connectors) |
| PWM frequency | 50 Hz (standard RC servo) |
| Position range | 0–1000 (mapped to configurable pulse width) |
| Connector pinout | +5V / Signal / GND per channel |
Ramp profiles for smooth, controlled motion:
| Profile | Description |
|---|---|
| LINEAR | Constant speed, instant start/stop |
| SMOOTHSTEP (5 levels) | Gradual acceleration/deceleration — from gentle (15%) to very smooth (50%) |
Ramp time is configurable from instant to 25.5 seconds.
USB HID Host
| Parameter | Value |
|---|---|
| Power output | 5V, max 500 mA |
| Overcurrent protection | Yes (hardware) |
Supported devices: HID-class keyboards, mice, barcode scanners, RFID readers (HID mode).
USB HID events (key presses, mouse movements, scans) are forwarded to the Main PC via CAN bus.
CAN Bus
| Parameter | Value |
|---|---|
| Standard | CAN 2.0A |
| Baud rate | 500 kbps |
| Protocol | ER-Frame (custom) |
The module receives commands (set PWM, move servo, emergency stop) and sends events (input changed, servo position reached, USB HID event) over the CAN bus using the ER-Frame protocol.
Front Panel
| Element | Description |
|---|---|
| Display | 4-digit, 7-segment LED |
| Buttons | 3 — SEL, PLUS, MINUS |
| Status LEDs | RUN (green), STOP (yellow), ERROR (red) |
The CAN device address (1–255) is set using the +/- buttons and persists across power cycles.
Wiring
Bus cable (4 wires):
- 24V + GND — power
- CAN_H + CAN_L — communication
Minimum wire cross-section: 1 mm² (for all power and output wiring).
Topology: Daisy-chain bus with 120 Ω termination resistors at both ends.
Specifications Summary
| Feature | Value |
|---|---|
| PWM outputs | 8× (2.5 A each, 0–1000 resolution) |
| Digital inputs | 8× (dry contact, 10 ms debounce) |
| Servo outputs | 16× (50 Hz, 6 ramp profiles, up to 25.5 s ramp time) |
| USB HID host | 1× (keyboard, mouse, scanner) |
| CAN bus | 500 kbps, ER-Frame protocol |
| Supply voltage | 24V DC |
| Built-in converters | 12V / 4 A + 5V / 4 A |
| Idle power | < 0.7 W |
| Configuration | 7-segment display + 3 buttons |