Hardware init function profit a great deal from being inlined if the
given parameters are constant -- which is the common use-case, we could
probably call this for all timers and still have less overhead. The
hwtimer_pwm_ini (which calls hwtimer_ini) gets completely computed at
compile-time resulting only in the register settings of hwtimer_ini.
This is now possible because we get rid of static storage for the
max_ticks and instead compute this in hwtimer_pwm_max_ticks from the
timer register settings.
Some platforms are missing timer channels, this is now left to the
(missing) preprocessor definitions on those platforms, no
platform-specific defines needed anymore.
Also fix usage of timer counter register 3 (hardcoded) in
cpu/avr/dev/clock.c -- this code isn't used on many platforms as it
requires a very special quartz clock frequency but this now also uses
the platform timer specification.
We can now directly compile arduino sketches (.pde) files.
Arduino compatible analogWrite works now.
But there is still a long way to go, serial I/O and timer stuff (delay,
millis etc) currently don't work (not tested but I don't expect this to
work).
It can be used in an arduino sketch or in a normal contiki program.
We get a PWM frequency of 490.2 Hz (a period of 2.040 ms), that's
Arduino compatible. If you need different frequencies see native timer
usage in examples/osd/pwm-example
In a contiki program you have to call arduino_pwm_timer_init to
initialize the timer before pwm works. The arduino sketch wrapper
already does this.
For running a sketch, see examples/osd/arduino-sketch
Historically $(OBJECTDIR) was created when Makefile.include is read. A
consequence is that combining "clean" with "all" (or any other build
target) results in an error because the clean removes the object
directory that is required to exist when building dependencies.
Creating $(OBJECTDIR) on-demand ensures it is present when needed.
Removed creation of $(OBJECTDIR) on initial read, and added an order-only
dependency forcing its creation all Makefile* rules where the target is
explicitly or implicitly in $(OBJECTDIR).
The boot loader now knows when to go into bootstrap mode by
looking for a specific EEPROM value. Also updated code style
to match Contiki code style guidelines.
This commit moves the Settings Manager from the AVR codebase
into the Contiki core library. Any platform that implements
the Contiki EEPROM API can now use the Settings Manager's
key-value store for storing their persistent configuration info.
The Settings Manager is a EEPROM-based key-value store. Keys
are 16-bit integers and values may be up to 16,383 bytes long.
It is intended to be used to store configuration-related information,
like network settings, radio channels, etc.
* Robust data format which requires no initialization.
* Supports multiple values with the same key.
* Data can be appended without erasing EEPROM.
* Max size of settings data can be easily increased in the future,
as long as it doesn't overlap with application data.
The format was inspired by the [OLPC manufacturing data format][].
Since the beginning of EEPROM often contains application-specific
information, the best place to store settings is at the end of EEPROM
(the "top"). Because we are starting at the end of EEPROM, it makes
sense to grow the list of key-value pairs downward, toward the start of
EEPROM.
Each key-value pair is stored in memory in the following format:
Order | Size | Name | Description
--------:|---------:|--------------|-------------------------------
0 | 2 | `key` | 16-bit key
-2 | 1 | `size_check` | One's-complement of next byte
-3 | 1 or 2 | `size` | The size of `value`, in bytes
-4 or -5 | variable | `value` | Value associated with `key`
The end of the key-value pairs is denoted by the first invalid entry.
An invalid entry has any of the following attributes:
* The `size_check` byte doesn't match the one's compliment of the
`size` byte (or `size_low` byte).
* The key has a value of 0x0000.
[OLPC manufacturing data format]: http://wiki.laptop.org/go/Manufacturing_data
This magic comes from the `--gc-sections` linker flag, which turns on garbage collection for unused input sections. The compiler flags `-ffunction-sections` and `-fdata-sections` make sure that each function and each static data definition have their own section. The result is that GCC can prune away all unused symbols, reducing the size of the resulting executable.
These optimizations may be disabled by setting the Makefile variable
`SMALL` to zero.
