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11 commits

Author SHA1 Message Date
James Devine acf6bf76eb microbit: further fixes to #73
issue #73 highlighted an issue whereby the destruction of an instance
registered as an idle or system component, would result in a hardfault.

This was due to not deregistering idle or system callbacks.

This patch has been applied to all components currently in use by the
idle or system callbacks.
2016-01-13 16:25:34 +00:00
James Devine 1cc814da60 microbit: further formatting corrections
Corrected trailing whitespace, and tabulated lines with no content for:

* MicroBitCompass.h (.cpp)
* MicroBitDisplay.h (.cpp)
* MicroBitMessageBus.h (.cpp)
2016-01-13 16:16:18 +00:00
Joe Finney 0e7a6979da microbit: Comment Cleanup
corrections to comment blocks only.
2016-01-09 11:54:23 +00:00
Joe Finney d51b1205f7 microbit: Added support for compass tilt compensation
An e-compass solution requires knowwlede two pieces of data to provide an
accurate heading:

  - Accurate calibration of the magnetometer hardware so that reliable
    measurements can be taken.
  - Knowledge of the pitch and roll of of device, so that the correct
    components of the X/Y and Z axis sensors of the magnetomer can be used
    to sense the magnetic field in a horizontal plane regardless of the tilt
    of the device.

This commit represent changes to the MicroBitAccelerometer and MicroBitCompass
classes to implemen tthese goals. More specifically, this commit provides:

 - The introduciton of an interactive calibration 'game', that can rapidly
   gather all the data required to calibrate the compass.

 - An improved calibration algorithm based on a Least Mean Squares approach of
   compass samples, as documened in Freescale Application Note AN4248.

 - The inclusion of a simple Matrix4 class to enable efficient Least Mean
   Squares implementation.

 - A change from asynchronous to synchronous calibration of the compass when
   first used. This is in repsonse to a feature request for this from users
   and high level languages using microbit-dal.

 - Support for detemrining tilt and roll angle in MicroBitAccelerometer

 - Support for multiple co-ordinate spaces in MicroBitAccelerometer and
   MicroBitCompass. Data can now be read in either RAW (unaltered) data.
   MICORBIT_SIMPLE_CARTESIAN (as used previously) or NORTH_EAST_DOWN
   (the industry convention in mobile phones, tablets and aviation)

 - Implementation of a tilt compensated algorithm, used when determining
   device heading.
2016-01-09 00:20:19 +00:00
Joe Finney 823a956d68 microbit: First cut at updates to provide tight validation within the runtime code, with a view to moving
NOP/clamping behaviour out of teh micro:bit runtime and into the glue layers of higher level
languages.

 - Updates to many functions to provide explicut return codes.
 - Updates to many functions to remove heuristic calidation (NOP/clamping/defaults)
 - Updates to ErrorNo.h to provide clearer return values, and place return values in a better scope
 - Updates to MicroBitDisplay to use enums where appropriate.
2015-10-25 21:51:33 +00:00
Joe Finney 18236810a3 microbit: BLE Profile Beta 1
First functionally complete BLE profile, matching BLE speicfication v1.6.
More specifically, the following services are now functional:

  - AccelerometerService
  - MeganetometerService
  - EventService
  - TemperatureServide
  - IOPinService
  - DFUService
  - ButtonService
  - LEDService

Also, updates to underlying device drivers to enable greater configurability:

  - MicroBitCompass now supports variable sample rates and temperature sensing
  - MicroBitAccelerometer now supports variable sample rates and ranges
  - MicroBitThermometer introduced
  - MicroBitMessageBus adapted to permit enumeration and block removal of listeners

Finally, MicroBit DFU Service has been changed to the new UUIDs specificed in v1.6 of BLE spec.
2015-09-28 21:40:44 +01:00
Joe Finney 4314b68643 microbit: First implementation of Temperature Service 2015-09-23 22:15:44 +01:00
Joe Finney eb5ed28f74 microbit: First cut at MicroBitButtonService and microBitIOPinService
Strictly still development - untested code.
2015-09-22 16:13:08 +01:00
Joe Finney ae0e5611c3 microbit: First draft of reconfigurable frequencies of MicroBitCompass 2015-09-19 21:00:38 +01:00
Joe Finney 857a626ed0 microbit: Memory Optimisation Mega Update
This release contains a widespread set of updates and optimisations to the micro:bit
runtime, with a view to reducing the SRAM footprint of the whole system. This is to
provide as much usable HEAP storage for application programs as possible.

Specific updates and optimisations include:

  - Additional compilation flags to allow the core micro:bit runtime to be configured.
    These are defined in MicroBitConfig.h

  - A custom heap allocator. This is now included for two reasons:

    1) To provide a simple mechanism to to utilise both the mbed heap space and other memory
       regions (such as unused memory in the SoftDevice region) as a single virtual heap.
    2) To address some issues that have been noted that are attributable to heap fragmentation.
       The micro:bit heap allocator has a simple algorithm, but one that is chosen to respond
       well to the relativelt high 'heap churn' found in the micro:bit environment.

    All micro:bit components and user programs now use this heap allocator trasparently.

  - Updates to BLE services to remove persistent references to their GATT services. This consumes
    vast amounts SRAM, rather unecessarily. Instead only handles to the relevant GATT characteristics
    are now stored. This specifically includes:
      + MicroBitDFUService
      + MicroBitEventService
      + DeviceInformationService

  - Updates to the Fiber scheduler to save SRAM. More specifically:
      + Removed the need to hold an empty processor context to intialise fibers.
      + The IDLE fiber now runs without a stack
      + fiber stacks are now only created when a fiber is descheduled for the first time, thereby reducing heap churn.
      + the 'main' fiber is now recycled into the fiber_pool if it leaves app_main()
      + fibers created through invoke() now only maintains the necessary part of teh parent stack that is needed, thereby
        reducing the stack size of spawned fibers.

  - Updates to the Message Bus to reduce the overall memory footprint of processing events. More specifically:
      + Event handlers are now always called using invoke(), such that non-blocking event handlers no longer need
        a dedicated fiber to execute - thereby saving SRAM and processor time.
      + Processing of events from the event queue is now rate paced. Events only continue to be processed as long as there
        are no fibers on the run queue. i.e. event processing is no longer greedy, thereby reducing the number of fibers
        created on the runqueue.

  - Updates to BLUEZOENE code to bring up core BLE services even if they are not enabled by default. This allows
    programs that do not require BLE to operate to benefit from the full range of SRAM, whilst still allowing the
    device to be programmed over BLE.

  - Updates to the Soft Device initialisation configuration, reducing the size of the GATT table held in the top 1.8K
    of its 8K memory region to around 800 bytes. This is sufficient to run the default set of BLE services on the micro:bit
    so the additional memory is configured as HEAP storage by MicroBitHeapAllocator.

  - Minor changes to a range of components to integrate with the above changes.
    + rename of free() to release() in DynamicPWM to avoid namespace collision with MicroBitHeap free()
    + rename of fork_on_block to invoke() to enhance readbility.

  - Many code cleanups and updates to out of date comments.
2015-08-31 23:25:10 +01:00
James Devine 538e1c48bd microbit-dal: Initial Commit
This is the first commit of the microbit-dal on GitHub.
This repository contains the runtime, which is a light
weight operating system developed by Lancaster University.
2015-08-12 11:53:41 +01:00