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:

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):

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