Migration from nRF52840 to nRF52833

[Raffaela]

Hi everyone,

I have developed a Zigbee application for the nRF52840 board and now I need to migrate to the nRF52833 board.

Are there any indications on how to proceed at the moment? For example on which SoftDevice is best to use to avoid memory problems? Or should the application run without too many problems? Any suggestions are welcome.

Thank you,
Raffaela

[Hung Bui]

Hi Raffaela, 

Which softdevice are you running on nRF552840 ? on NRF52833 you can run either S113 or S140 or S122. Depends on your requirement you can choose between them. 

I think the easiest to port an application from nRF52840 to nRF52833 is to compare the project examples we made in the SDK. For example, you can check the ble_app_uart project. You can use an text editor, Notepad++ for example, to do compare between the  ble_app_uart_pca10100_s140.emProject file and ble_app_uart_pca10056_s140.emProject (if you are using SES IDE ) file to see what need to be modified. 
Basically it's the startup files need to be changed, RAM, FLASH configuration, cryptocell missing. 

[Raffaela]

Hi Hung,

Thank you so much for your answer.

About the FLASH configuration, I have a problem to understand the address of the beginning of NVRAM: it is at the end of the flash memory but what I wonder is if it is automatic that, by changing the limits of the flash, the limits of the NVRAM are also changed.I searched as you told me but at the moment I only found the limits of the FLASH and RAM memory.

Thank you for your time,

Raffaela

[Hung Bui]

Hi Raffaela, 

In the above picture, I compared the 2 SES project files using the Compare tool in Notepad++. As you can find the start address of RAM is the same, this is because the application's RAM start address is always located right after the RAM area reserved for the softdevice. If it's the same application, the RAM required by the softdevice will be the same, so the RAM start address is the same. Same applied for FLASH_START address. 
What difference here is the difference in the size of RAM for application and the physical size of the RAM. 
If your application doesn't use crypto cell, there isn't much else need to be updated. Except for the device name, the startup .s file, the system_nrf528xx.c file. Please use the compare tool to locate all the differences.