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Using a Relay ISOx16 board with Panda II or Cobra II


#1

I’m looking at my ISOx16 relay module and trying to figure out how to make it work with my Panda II and later with a Cobra II. Haven’t found any doc on the product. Is there a manual/spec sheet? If not, here’s my thoughts and questions:

  1. I count three terminals per relay (48 total). I’m guessing two of these go the load controlled by the relay, in my case 12VDC and ground. Which two are which and what’s the third for?

  2. To control the relays, I plan on connecting 7 GPIO on the Panda to either an extender module connected to the end of the gadgeteer cable that goes to the relay board or what about the 20 male pins, arranged in two rows of 10, that stick up right behind where the cable attaches to the relay board? Can a female x female header be attached to either row of 10 pins to receive the wires from the Panda?

  3. Finally, how do i control the 16 relays with 7 GPIO pins?


#2

Thanks, Andre. Yes, i saw that one but the code uses
relayISOx16.EnableRelay(RelayISOx16.Relay.Relay_1);
which i’m guessing relies on a gadgeteer library which, i’m guessing, can’t be used with a Panda or Cobra.


#3

Thanks, Andre. I’ll take a look. Better, of course, would be a user manual for the product!


#4

@ Matt5, I agree that ordinarily a manual is nice to have. These are Gadgeteer modules though, the intent is that you don’t need to know the details, you can just put the module on the design surface and use the methods it exposes. As Andre said, you can take the code and put that on any board you want - you may find there is some Gadgeteer specific code that you’ll need to change back to using pure netmf, but again that should be a relatively simple process. From the code, you can reverse engineer the capabilities you need, but in most cases the code makes it an easy transition.


#5

Thanks, Brett. I see your point about the Gadgeteer modules, so i’ll dive into the code. So hopefully i’ll eventually figure the answer to Q3, but what about the other two, admittedly basic, questions, i.e. 1) how do i wire the load to the three terminals per relay and 2) can i use 10 of the 20 male pins that are sticking up behind the gadgeteer cable attachment (fat chance)?


#6

Controlling the relays with the gadgeteer code looks simple. Also found Keith asked the same question a month ago over on the Gadgeteer forum:
http://www.tinyclr.com/forum/topic?id=10368
He found the same thing i did, that pins 6 and 8 are not used.

My only question is if the code
GTI.DigitalOutput(socket, Socket.Pin.Seven, false, this)
is the same as writing to a GPIO pin, which i’m guessing it is (without pursuing GTI).


#7

It is the same.


#8

Thanks, Architect.

OK, I think i’ve figured out how to wire up the load. The three terminals are SPDT (single pole, double throw) so the middle one is common which is connected to the the right terminal when the relay is off and connected to the left terminal when the relay is on. This assumes the little sketches on the board by each relay showing the common connected to the right terminal is what is when the relay is off. The ground, of course, doesn’t need to connect to the board, but can run from the load straight to ground.