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gca-wioboost-en

WIOBoost Central DCC station, booster or Motor controller.


Copyright Rob Versluis and Peter Giling


Description

This unit , commanded via Wifi, is using the same firmware of WIO_01.
It uses the same H-Bridge as used in ORD-3 booster, giving a max power of more than 3 Amp.
By simply making the right settings, WIOBoost will behave as described:

  • DCC Central station (display connection also available)
  • Booster with its own current limit switch.
  • PWM motor speed control.

The complete WIOBoost is basically not more than an ESP8266 D1 module, a power driver L6203 and a voltage regulator.
The large white resistor in the midle of the board is a 0,47 Ohm resistor where the current is measured.
The standard A/D converter in the ESP is not really accurate, but yet suitable for overcurrent protection.

Power supply

The WIOBoost is set up in the same way as ORD-3, with its own DC rectifier and switching power supply.
The enables to adapt the voltage to rails adapted to the scale you are using.
There are a few levels that should be considered.
N scale needs 12 - 16 Volt
HO scale needs 15 to 20 Volt
Scale G, 1 and 0 need 19 to 24 Volt
It is advisable to select the right voltage for the WIOBoost.
The WIOBoost will be available as complete kit or just pcboards.


Central station

When WIOBoost is set for DCC, it will provide the loc commands to the rails, with a maximum current of approx 3 Amps.
The default setting for the WIO output current is set to 1 Amp, and can be changed in the WIO settings.

Booster

In fact the same function as central station, but the pulses com in from another WIOBoost.
Booster will switch on its rail output, when a decent DCC signal is received.

Motor drive

The pulse output from D32 can also be set as PWM, which will control the speed of a connected motor.\

Short circuit protection

Th L6203 is provided with its own high current and high temperature protection.
But in practice we need a faster reaction on too high current.
The booster itself (like the central station), will shut off when the max amps is reached.
This maximum current, by default set tot 1 Amp, can be changed in WIO settings.
After shut off, the WIOBoost will wait approx 5 seconds, and after that will try to start up again.
In this short circuit situation, the pulses from the central station remain available, even when the
central station itself found short circuit.
The H-bridge is controlled that way by the enable input, without effecting eventually connected following WIOBoost units.

Multiple boosters

Tne IBB1 connector of the WIOBoost is available for connection a following -as Booster set- WIOBoost.
Railsections, connected to different boosters, should be separated with al least on rail cut of the two.
The short time that a train is getting power from two boosters, is no problem at all.
Even the cutout for Railcom is 100% in phase, between boosters.

Connections

IBB1

Inter Booster Bus.
To connect the next booster .
Important note: All WIOBoost units, that are interconnected via this way, should have their own power supply, isolated from each other.

SER1

A standard serial bus connection, same as om GCA_PI01.
So far, used to connect an ID-12 RFID sensor.
Further applications might be developed.

IIC1

The standard I2C connector.
This bus is very large in options, so far now, only used to connect a display.
The supply for the display can be selected with JP1 between 3,3 and 5 Volt.

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Hardware

Assembling remarks

Put all parts in same order as on parts list, including the headers for LOlinD1.
The usb connector for programming can be reached while on board.
VIN is to be connected to any suitable transformer or power supply. After switching on power, check voltage on 5V & GND pins of U1 (pins closest to IIC1).
If this unit is supposed to function as booster, first make configuration without IBB1 connected.

gca-wioboost-en.txt · Last modified: 2020/03/14 21:27 by smitt48