This sensor works with a frequency of 13,56 Mhz.
On the picture it is at the right hand side.
It is very fast and reliable, but it is has a passive output.
This means that it will receive the transponder data, but will not send anything unless it is asked for.
So it needs a two way communication to get this data into the GCA51.
The sensor can communicate in three different ways:
SPI ( 7 wires needed), Serial Programming Interface. This is the default setting for RC522.
I2C (4 wires needed), Inter Integrated Circuit, but some modifications on RC522 have to made to use this option.
RS232 (4 wires needed), also here modifications are necessary.
To avoid these modifications, the choice is made for SPI.
Only an angled 8 pin PSS 254-8W connector needs to be soldered on the RC522, to make it suitable for GCA51 where the identical connector in straight version is used.
The power of 3.3 V is coming from Arduino Uno board.
As transponder, there are hundreds of options, but experiments where very succesfully with a NTAG213 sticker.
This 12 x 19 x 0.2 mm transponder does miracles, except when directly fixed on metal surface.
But that could be overcome by usig an extra ferrit foil of 0.5 mm thickness.
In addititon to this, a 6x20mm tag is now available, making it also useable under tt & N-track.
This second tag is also rwuipped with mabnetic shielding.
The RC522 sends a large amount of bytes , but for Rocrail only 7 bytes are interesting.
But that still opens so many possible numbers that it is almost impossible to ever find the same number twice.
For your indication: you will have a chance of 1 out of 2567 posibillities to find one.
Installing the sensor is another problem to be solved by your own imagination.
Some ideas will slowly follow here, hopefully also with the feed-back from enthousiastic users.
The connection is made with a PSK254-8W connector on both sides.
The correct use of this connector avoids mistakes in connecting, because that will destroy RC522.
Only 7 wires are needed:
|RC522 sensor||GCA41/GCA51 (RC522)||Remark|
|1||1||'1' Mark is visible on PSK connector|
|5||5|| Not used
no wire needed
|7||7|| Not used
no wire needed
| GCA41 (S1) |
| CAN-GC4 (Rf1..8) |
| GCA_PI01 (S1) |
|2||2||1 *||+5V||'1' Mark is visible on PSK connector|
Remark : attention to different numbers on GCA_PI01 !!
For those who like to experiment a bit further, there is a smal pcboard coil for
both HO- and N-scale.