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LJimé.1
Associate III
Nov 17, 2025 1:39 PM UTC
Solved

Changing the default I2C address of STSAFE-A120

Hi,

I would want to know the default I2C address of the STSAFE-A120 and if it is possible to change it, as it is done in the A110.

In addition, is there any documentation about the content of the STSAFE-A120 I2C registers?

Thank you in advance.

Regards,

Luis

Benjamin BARATTEBest answer
ST Employee
Nov 24, 2025 12:25 PM UTC

Hi @LJimé.1 ,

 

The STSAFE-A120 I2C address is part of the customization, therefore, it's describe in the application note on the evaluation profile here

The default value is 0x20 on 7 bits.

 

Yes, this value is updatable as on STSAFE-A110.

 

The STSAFE-A120 is not based on registers. It's a frame based protocol. Therefore, the STSELib is here to manage the frame creation as an helper to your application.

You need to provide a simple send/receive I2C API to have it working on your device.

 

To update the I2C address, you have the command stse_put_i2c_parameters function.

Warning, once made an update of the I2C address, you will need to reset the STSAFE-A120 to apply the new I2C address and restart you STSELib handle with the new I2C address.

 

Best Regards,

Benjamin

2 replies

Benjamin BARATTEBest answer
ST Employee
Nov 24, 2025 12:25 PM UTC

Hi @LJimé.1 ,

 

The STSAFE-A120 I2C address is part of the customization, therefore, it's describe in the application note on the evaluation profile here

The default value is 0x20 on 7 bits.

 

Yes, this value is updatable as on STSAFE-A110.

 

The STSAFE-A120 is not based on registers. It's a frame based protocol. Therefore, the STSELib is here to manage the frame creation as an helper to your application.

You need to provide a simple send/receive I2C API to have it working on your device.

 

To update the I2C address, you have the command stse_put_i2c_parameters function.

Warning, once made an update of the I2C address, you will need to reset the STSAFE-A120 to apply the new I2C address and restart you STSELib handle with the new I2C address.

 

Best Regards,

Benjamin

LJimé.1
LJimé.1Author
Associate III
Nov 25, 2025 8:14 AM UTC

Hi Benjamin,

Thank you very much for your answer!

Regards,

Luis