Activate GPO pin with iOS code

[ADura.2]

Hi all,

On a M24SR series NFC tag, after writing a NDEF message I need to activate GPO pin to wake up the MCU.

On Android with java, this method exists: activePinGPO(NFCTag tag, OnNFCListener listener);

And I'm trying to find the same method for iOS.

Just for be more precise, I'm using NFCISO7816APDU to send messages. So I'm wondering if I can manage GPO pin with APDU as well because it's not written on the datasheet.

Any idea?

Thanks!

[victor laraison]

Hi Adura,

in iOS, our NFC tap does not support the Type4A tags for the meantime : we are working on it. We"re using our java ST25SDK translated into ObjC. This includes all the classes for M24SR tags.

BUT, for GPO, normally you cannot activate it on our M24SR :

"/**

   * On M24SR, we cannot modify GPO value by RF - Only read is enabled

   */

"

I will double check with our Product Owner here, but I m pretty sure you cannot program GPO on M24SR.

Otherwise, it is possible to use the APDU commands for sending messages with Type4a tags in iOS.

Stay tuned...

[victor laraison · Accepted solution]

hi again Adura,

After verification, GPO mode is only configurable by I2C and not by RF.

By RF, you can only read GPO mode and GPO value, and that"s all.

hope it clarifies.

[victor laraison]

ref to table6 of M24SR datasheet

[ADura.2]

Thanks Victor for your answer. I'll check with hardware engineers what they want to do and how they want to proceed.

I just know that I'm using activePinGPO function on Android but I quite don't know what it exactly does.

But I'll find out with the guys and get back to you if I need anything else.

Good day!​

[PBOUZ.1]

I Victor,

I am working with Adura on this project and I would like to go deeper on our issue because we still didn't solve it.

Actually, the issue is not about configure the GPO mode with RF. We are aware that GPO mode is only configurable by I2C. In fact, we set up the GPO to "State Control" (p.19 in the datasheet) with I2C before starting to interact with it through RF.

This mode allow us to drive GPO pin by sending a "valid Set GPO command" (quote from the datasheet). As mention Adura in his first post, we are able to do it on Android, by using the activePinGPO found on your android library.

As you mentioned later, this library does not exist in iOS environment. So, we would like to know if there is any way today to get as the same result as using activePinGPO method, but in iOS environment.

Thank you for taking your time to help us.

[victor laraison]

Hi pbouz,

I'm not able to find any "activePinGPO" into our android library. Please, could you tell me where to find it ? ST25SDK android or NFC Tap App ?

Thx and br,

[PBOUZ.1]

You are right, this function was written by a developer who worked on the project before us, sorry for misleading you.

We manage to understand now what is happened and how to fix our issue.

The function "activePinGPO" use a lib "Type4Utils" (I don't know the source of this but it seems it doesn't use your ST25SDK) to send APDU command to the tag, in our case the StateControl command.

In iOS environment, we found that NFCTagReaderSession (on the NFC Core) with a NFCISO7816Tag can also send APDU command to get the same result.

So we are planning to go on this way for our project.

Thx for your support Victor.