GPIO pin mapping mts-io-sysfs?

[Conrad Ljungström]

Hello!

I am going to try to attach a sensor and read some input from it, but I don’t understand the mts-sysfs-io mapping, so I thought i would check.

On this page it says for example that pin 7 is “External Input 6”.

http://www.multitech.net/developer/products/multiconnect-ocg/hardware/multiconnect-ocg-d/gpio-connector-and-cable-information/

However, on this page which is supposed to explain the interaction with the pins there is no mentioning of which input is pin 7. This has led me to guessing that the din6 that is mentioned here is the Digital Input 6 which I can only hope means the same as the “External Input 6” from the page above.

http://www.multitech.net/developer/products/multiconnect-ocg/hardware/multiconnect-ocg-d/mtcdp-io-control-using-mts-io/

So my question is, is this correct? I feel so lost : )

[Jesse Gilles]

You are correct, din6 (Digital Input 6) is the same as External Input 6 — just inconsistent naming. Sorry for the confusion.

Jesse

[Jesse Gilles]

I updated the connector page to rename the pins as “Digital Input/Outputs” to better match with the driver names.

[Conrad Ljungström]

Right, thanks. That’s awesome. I just have one more question, if I do:

# mts-io-sysfs store dout0 1

and then i cross the corresponding cable/pin for din7 with the dout0 cable/pin should I not get a 1 when doing:

# mts-io-sysfs show din7

Or how does that work? 🙂 Sorry, this must seem like childishly stupid questions for you.

/Conrad

[Jesse Gilles]

The output pins are open collector outputs to make them more flexible for driving different types of circuitry (relays, etc) — this means the pin is floating for a logical 1, and driven to ground for logical 0. If you want to use the output as a standard digital out, you need an external pullup resistor to create a high voltage level.

Here is more information:

http://www.multitech.net/developer/products/multiconnect-ocg/hardware/multiconnect-ocg-d/gpio-interface-electrical-requirements/

Also, I’ve left the pin names on the website as External Input/Output and updated the doc on the mts-io driver to match instead.

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