Interfacing nRF54L15 from nRF9151 without Custom Firmware

[taylor_ca]

Hi,

We are looking to add an nRF54L15 chip to our custom nRF9151 board, to support Bluetooth. We also would like to add NFC functionality and additional GPIO pins from the nRF54 chip, however, we don't want to have to flash and manage separate custom firmware for the additional chip.

Is there a way we can configure the nRF54 chip using a soft device or something similar, so that we can control the GPIO/NFC/BLE from the nRF9151 and not have to write custom firmware for the nRF54?

Cheers,

Callum

[Asbjørn]

Hello Callum,

If I understand you correctly you want to use the nRF54L15 as a serial modem with NFC and GPIO control along with BLE connection. This is possible to do, but not the way I think you are hoping for. The nRF54L15 comes with an empty memory and no option of configuring it through GPIOs or serial interface directly. You would have to implement FW that would achieve the functionality that you want. You could in theory avoid programming it in production by using GPIOs from nRF91 to program the nRF54L15 with a predefined hex that you incorporate into the hex image you program to the nRF91. That said, it's not a smooth operation either, but technically an option. You would probably be better off with having two hex files and program them separately.

Best regards

Asbjørn

[taylor_ca]

Thanks for the response. Can I check how Nordic implements the software for boards like the Thingy:91 X which have both nRF9151 and an nRF53. With LED2 (which is connected to the nRF53) and using the default firmware that Nordic flashes onto these chips at the factory, is there a way I control LED2 from the nRF9151 using serial or some other protocol? Or do I have to flash custom firmware onto the nRF53 to handle controlling LED2 from the nRF9151. 

Flashing both chips in production isn't an issue, we are more curious if there is an existing firmware from Nordic that exposes the nRF54's GPIO/BLE/NFC control over serial (like a soft device). Although not complicated, if we don't have to create and manage another set of firmware for the nRF54, that would be ideal.

Let me know if I can clarify my question.

[Asbjørn]

Hello Callum,

Thanks for the update, the FW used on Thingy are available in NCS as well. You can select the thingy:91x with the build configuration and selecting the HW there. That would be the closest to the setup you have in mind indeed.  There's "Hello nRF Cloud" with sensordata from both nRF5340 and nRF9151 that could be a starting point?

https://www.nordicsemi.com/Products/Development-hardware/Nordic-Thingy-91-X/Download?lang=en#infotabs

Best regards

Asbjørn