...so, nrf51822 (Rev2 SRAM=16KB) are useless with Zephyr rtos?

[Marcelo Aleks]

I've already tried to set some zephyr configs, but n51822 to run as peripheral it nedds at least ~20KB

Have anyone got success or all the nrf51822 QFAA H2 will really never work ?

[haakonsh]

There's not support for the nRF51 series in our NCS sdk and there's no plans to add it in the future either. 

The nRF51 series is not intended for new designs. By next year they won't be qualifiable with BT SIG anymore as they can't keep up with the BLE spec. 

You can use the nRF51 series for proprietary RF ofc.

[Marcelo Aleks]

haakonsh thank you for the information.


We already bought many nRF52840 but it will take 1-2 months to arrive, so we would like to use the time to develop some code learning the internals. 

We are using these MCUs because we have a lot  ( nrf51822 QFAA [rev1 and rev2 == 16KB], but we saw on the video below:


Marcel compiles the zephyr bluetooth samples and it always consumes less than 16KB. What magic is that ?-D

We are not having success to do that, even using the bbc_microbit as board profile.


Regards

[haakonsh]

He probably built with as few components as possible, or the components he used required less RAM in 2017 than now.

We will start supporting the nRF52 series in our nRF Connect SDK (NCS) very soon, but we will not support nRF51 with NCS. 

[Marcelo Aleks]

They already there. There are boards nrf52xx in the boards directory on https://github.com/NordicPlayground/fw-nrfconnect-nrf/tree/master/boards/arm.

I've been capable of compile to nrf51822! Tweaking buffer sizes and making other changes. It is really very good!


Why do you not migrate all the nrf stuff to the zephyr main repository ? No all, but the enough to make anyone compile the NCS samples.



 

[haakonsh]

We work with a downstream repo of Zephyr, at regular intervals we upmerge stuff back into the Zephyr Project. We support NCS, and not zephyr directly. 

[Marcelo Aleks]

haakonsh thanks!


But what happens when someone is using the NCS repository to develop a nrf solution, but, at the same time, needs some feature that is only on the zephyrproject-rtos rep ?

[haakonsh]

They'll have to make that integration themselves, if it's just a single PR then it can be painless to merge it into a given version of Zephyr that is used in the given version of NCS. 

We try not to lag too far behind zephyr though and many of the critical updates/features for our devices will come from us downstream and up to Zephyr Project, then we will make another release of NCS with the current version of Zephyr (that just merged the given pull requests). We release tags of NCS, but we also use the Master branch to stay as up-to-date with the Zephyr Project as possible. 

We can only support NCS with a given version of Zephyr as we do a lot of testing 24/7. If we would support any version of NCS with any version of Zephyr the matrix of tests required would grow exponentially with new releases of NCS and Zephyr.