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title: Pebble SDK 3.10-beta2 - Changelog
date: 2016-02-19
---

This is a pre-release SDK, containing a preview of the new Pebble Health
API.

The following release notes list only changes since [3.10-beta1](/sdk/changelogs/3.10-beta1/).

### Changes to Firmware

* ``health_service_get_measurement_system_for_display`` no longer crashes when called on
  real watches.
* ``rand`` is now seeded from the hardware RNG on app start, as it was in firmware 3.4 and
  earlier.
* An issue causing the sleep graph to sometimes be blank on the deep sleep display of the
  Health app was resolved.


### Changes to SDK

* `CFLAGS` and `LINKFLAGS` env variables are now correctly honored by the app build process.
* JSON files under the `src/js/` directory are available to `require` in newly-created projects.
* ``persist_write_bool`` and ``persist_write_int`` are now correctly documented to return the
  number of bytes written on success.