User Tools

Site Tools


GCA-PI07 Transformer Sensor


Sensoring trains is a very essential part of automatic train control.
Rocrail is no exception for that.
There are various ways of keeping track of your trains.
For a longer time GCA93 current detector has been widely used because its excellent reliliability.
This GCA93 is also, coinnected to a GCA_PI02 very useful for RocNet network.
But there is one very little disadvantage, using current detectors like GCA93 :
It looses 1.2 V of your booster power.
In practice it is hardly noticeable, specially with the modern decoders with load control.
The GCA_PI07 is made in a different way, which avoids this 1.2 V lost.
There is hardly any loss at all (approx 5 mV)
The diasadvantage is a larger board, compared to GCA93.
Max four of these boards are to be connected to one Raspberry Pi.
A dip-switch on board selects the adress, see table below.
The sensibility of two groups of 4 inputs can be influenced by jumpers.


  • 8 current inputs on each board
  • Direct link to I2C in RocNet.
  • Very low power loss due to use of transformers.
  • Total 32 sensoro inputs to one Raspberry Pi.
  • The load per sensor is reported to Rocrail for Background Color.

The Hardware

Final product Professional board
gca_pi07_pict03.jpg gca_pi07_pcbpict.jpg

Dip Switch settings

Maximum of 4 boards can be used to one Raspberry Pi.

sensors SW 1 SW2
1..8 OFF OFF
9..16 OFF ON
17..24 ON OFF
25..32 ON ON

Jumper settings

Jp1 and Jp2 are to seelct a more or less sensitivity to the inputs.
There indications on board : 5 and 3.
Normal settings will be a jumper to pos 5.
If you need a lightly better sensitivity put the jumper on pos 3.
Jp1 is for input 1..4.
Jp2 is for input 5..8.


N.B. Only complete ordered kits will be supported!

gca-pi07-en.txt · Last modified: 2018/12/04 14:56 by rjversluis