Ports not working on GCA50 /MGV50.

RocNet(RaspberryPi), mergCBUS and LocoNet based hardware developed by Peter Giling. (GCA)
Documentation: http://wiki.rocrail.net/doku.php?id=english#hardware
Order information: http://wiki.rocrail.net/doku.php?id=gca:gca-index-en/

Ports not working on GCA50 /MGV50.

Postby DerrickS » 26.05.2012, 23:09

I have five GCA50 i/o units, four of which have been added to my layout.
I use these four to monitor reed switch inputs.
On these four units the following ports do not work.

Unit 1 port 16
Unit 2 port 8
Unit 3 port 8
Unit 4 port 8

I have got out my multimeter and checked the voltage on all of these ports and confirmed that they are connected to VCC via RP1/RP2. I have not done any further tests to confirm that the ports are connected to the PIC. It occured to me that there may be a software problem (because of the common port 8 ).

Anyone know?

Derrick
DerrickS
 

Postby phg » 06.06.2012, 16:23

Hello Derrick,

It is possible that they might not work, because GCA50 needs minimal 80 mSec pulse, before it will send any useful info to LocoNet.
Reed switch pulses could be severely shorter
Best regards, herzliche Grüße, chaleureuses salutations, saludo cordial, migliori saluti, hjärtliga hälsningar, hartelijke groet,

Peter Giling (Rocrail - LNet(GCAxxx) - Fiddle Yard control GCA145 - CBUS (CAN-GCx)- RocNet (Raspberry Pi GCA-PIxx)
phg
 

Postby DerrickS » 06.06.2012, 21:32

Hello Peter,

Thanks for the information.
Can I also thank you for the excellent kits that you produce the quality is second to none.

I don't think it is a timing problem because when I move the the reed switch to a different port it works fine. Also when I ground the ports manually, with a bit of wire, I only get an occasional response.

It is not causing me a problem because I have spare capacity but I thought I would put out this post because the problem was on similar ports on different GCA50's (it may be a problem with my soldering).

Best Regards,
Derrick
DerrickS
 

Postby phg » 07.06.2012, 12:47

Hello Derrick,

I have a feeling there might be a mistake in the position of both RP1 and RP2 resistor arrays.
They can be fixed in the wrong way, and that exactly could couse your problem.
There is a little mark on the array itself, as well as a mark on the PCB, but it is easily overlooked.
The marks on both arrays should be pointing to R1, or, if you have text on the board in readable position, pointing right hand side.
And if they are wrong:
I am not aware if you are good in desoldering, but the best way to avoid any damage to the pcboard, is just bending the array from one side to the other, until all pins break off.
Then with a soldering iron, heat up the pin on the bottom side and smash your hand with the board in it, to the table. All solder and the pin will go out.
After that, it is easy to put a new array in and then.... WATCH THE POSITION!
Best regards, herzliche Grüße, chaleureuses salutations, saludo cordial, migliori saluti, hjärtliga hälsningar, hartelijke groet,

Peter Giling (Rocrail - LNet(GCAxxx) - Fiddle Yard control GCA145 - CBUS (CAN-GCx)- RocNet (Raspberry Pi GCA-PIxx)
phg
 

Postby DerrickS » 07.06.2012, 20:34

Hello Peter,

I have just had a look at the circuit diagram and I now realise that pin 1 on RP1 and RP2 is the common feed for all the resistors.
I havn't yet checked the boards but what you suggest will almost certainly be the reason for the problems, because I wrongly assumed orientation didn't matter.

This will teach me to pay closer attention in the future! :oops:

Peter, thanks once again for your help.

Best regards
Derrick
DerrickS
 

Postby phg » 08.06.2012, 13:32

Hello Derrick,

One more thing :

If you can plan it in a way that GCA50, where resistors are wrong, is used as output, you do not have to worry about the arrays.
Best regards, herzliche Grüße, chaleureuses salutations, saludo cordial, migliori saluti, hjärtliga hälsningar, hartelijke groet,

Peter Giling (Rocrail - LNet(GCAxxx) - Fiddle Yard control GCA145 - CBUS (CAN-GCx)- RocNet (Raspberry Pi GCA-PIxx)
phg
 

Postby DerrickS » 08.06.2012, 19:51

Thanks Peter for that extra information.

Best Regards
Derrick
DerrickS
 


Return to GCA (Hardware by Peter Giling)