How is data shared between the nrf9160 and the nrf52840 on the Thinky91? Are there any example projects that demonstrate this?

[Mark P. Mendelsohn]

How is data shared between the nrf9160 and the nrf52840 on the Thinky91? Are there any example projects that demonstrate this?

[Øyvind]

Hello, 

In our NCS samples, we have the USB UART Bridge sample.

Kind regards,
Øyvind

[Mark P. Mendelsohn]

The source code for this sample shows it just moves data from a PC to a Thingy91 over USB. It does not show how to move data from the BLE side of the device to the Cellular side of the device. Do you have another suggestion?

[Mark P. Mendelsohn]

Sorry. That does not address the issue either. The requirement for the IoT implementation is to send data acquired from BLE to the cloud over the Cellular side of the chip and then be able to receive data back the other way. 

[Øyvind]

I'm sorry, I don't understand why this does not address the issue. The BLE HCI UART sample is used in the LTE Sensor Gateway, a sample that covers exactly what you are asking on the nRF9160 DK. 

Can you please elaborate on why it does not work? 

[Mark P. Mendelsohn]

The example creates an H4 connection between the BLE side of the chip and the cellular side of the chip. The nrf52840 is capable of running the entire BLE stack and Application by itself. This example would require the Application run in the nRF9160. Only H4 data could be transferred between the two prohibiting any local data from the BLE processor being shared. Even if you wanted to retrieve a version number of the program running on the BLE chip, you have no way of doing it. Often message passing over shared memory is used on IoT devices to accomplish this task.

[Mark P. Mendelsohn]

Another ticket with a similar question can be found here. https://devzone.nordicsemi.com/f/nordic-q-a/53279/thingy91-connections-between-9160-and-52840

The block diagram in the User Guide has a double-headed arrow between the 9160 and the 840 but no further details are given. The schematics of each chip are shown separately with no pins showing any interconnections between the two.

[Øyvind]

I'm sorry, do you mean the PIN MAP? It clearly states:

For nRF9160
P0.18	MCU_IF0	nRF52840 interface
P0.19	MCU_IF1	nRF52840 interface
P0.20	MCU_IF2	nRF52840 interface
P0.21	MCU_IF3	nRF52840 interface
P0.22	MCU_IF4	nRF52840 interface
P0.23	MCU_IF5	nRF52840 interface
P0.24	MCU_IF6	nRF52840 interface
P0.25	MCU_IF7	nRF52840 interface

For nRF52840
P0.11	MCU_IF0	nRF9160 interface
P0.15	MCU_IF1	nRF9160 interface
P0.19	MCU_IF6	nRF9160 interface
P0.20	MCU_IF2	nRF9160 interface
P0.21	MCU_IF3	nRF9160 interface
P0.22	MCU_IF7	nRF9160 interface
P0.25	MCU_IF5	nRF9160 interface
P1.00	MCU_IF4	nRF9160 interface

You can download a complete hardware file package from here: Thingy91 - Hardware files 1_0_1.zip

[Mark P. Mendelsohn]

Yes. That's it. Thank you.

[Øyvind]

Glad I could help! Let me know if anything else is unclear :)
Happy holidays!