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WIOesp & WIOpico


WIO is the abbreviation for Wireless I/O.

General I/O

The general purpose I/O is comparable with the Pi02/GCA50/CANGC2, using WiFi as wireless communication 'bus' instead of wired I2C/LocoNet/CAN, and is compatible with all known GCA Extension Units.
The main part of the needed I/O settings are defined in Rocrail, which makes a hardware swap al lot easier.


wioctrl-display.jpg The throttle supports the following configuration:

  • Rotary for speed, direction and selection of loco and function.
  • Up to 6 push buttons for functions and selection.
  • Display.
Only the ESP32, Lolin D32, is supported.

The in Rocrail defined locomotives can be transferred to the throttle(s) by sending the Short IDs. (Up to 256)



The General I/O is controlled by the I2C bus.(MCP23017) This I2C bus can simultaneous be used for:

  • Two I/O Expanders MCP23017 (32 I/O)
    • ESP32 and PicoW up to 4 MCP (64 I/O)
  • Two displays, compatible with RocDisplay.
  • One Sensor for temperature, humidity and pressure.
  • One Sensor for light.
  • Two 7-Segment display for time, date, temperature and simple dynamic text.
  • Play wave files in case of the LOLIN D32 with on board DAC output. (Digital Analog Converter)


Extra options, which needs accurate timing, are mutual exclusive:

  1. 64 LED chips control like the WS2812. (128 on PicoW)
  2. Four Servos.
  3. Two RC522 RFID readers.
  4. Mobile PWM motor control.
  5. CAN interface for 125/250kB standard/extended frames on TCP port 5550. (Binary)
  6. CAN Node in a RCAN compatible system, not using WiFi.

Serial RS232

The serial options are also mutual exclusive:

  1. Monitor. (default)
  2. RailCom reader.
  3. Mobile RFID reader.

I2C RocNetNode

The following RocNetNode boards are compatible with WIO:

Unit Description I2C Address(es) Remark
Pi02 32 I/O 0x20, 0x21 Only on WIOs without MCP23017 on board. Must start with 0x20.
Pi03 16 Servos 0x40 This will deactivate the Servo option, and can be used in combination with other options.
Pi06 Power supply and I2C HUB - For use in combination with the WIO-I2C.
Pi08 16 Dimming LEDs 0x60…0x67 Max. 8 units; 128 LEDs. This will deactivate the FastLED option.

Unit Description Replacement
Pi04 I2C Throttle WIO-Control
Pi05 Loco Controller WIO-Drive
Pi07 Transformer Sensor GCA94

Converter Cable


RJ12 RJ45 Name PSK 254/4W
1 2 +5V 4
2 3 I2C SCL 2
3 4 GND 3
4 5 I2C SDA 1

Kits & PCBs


For all basic functionality except throttle.
Features all needed connectors for all options.

WIO Boost

Specially for Option DCC with integrated 3A booster. (H-Bridge)

WIO Prog

Same as the WIO Boost but with an extra H-Bridge for Service Mode, Programming Track.

WIO Drive

Specially for Option DCC and Mobile with integrated 3A booster. (H-Bridge)
Note: Not compatible with the WEMOS D1 Mini; Won't boot. Use a LOLIN D1 Mini only for the WIO-Drive.


Command Station with booster from 1.6 to 20A.

WIO Control

A throttle based on LOLIN D1/D32 with display and rotary.
See WIO Control for functional information.


WiFi MBUS/RCAN interface.


Simple module with I2C buffer which connects to the Pi06.

WIO Clock

(Fast) Clock for 4" 7-segment displays controlled by PCA9622. (IO_CLOCK option in the USERCNF.h)
The time will be synchronised in case the NTP_CLOCK option is activated in the USERCNF.h.

RailCom Reader

A separate amplifier kit, GCA214, is available for reading RailCom data.

WIO WIO Drive WIO Control GCA214
wio_01_v2._pict3.jpgwio-02.jpg wiodrive.jpg . wio-control.jpg . gca214.jpg
General purpose I/O
and several options
DCC CS, Booster
and motor PWM
Throttle RailCom reader
wio-vc-1_pict_1.jpg wio_can_pict01.jpgwio_can_pict05.jpg
Command Station up to 20A 3A Command Station Interface WiFi-CAN Command Station

Functional Description


arduino/wio-overview-en.txt · Last modified: 2024/05/01 17:30 by babbel