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author | Marti Bolivar <mbolivar@leaflabs.com> | 2011-03-30 00:55:51 -0400 |
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committer | Marti Bolivar <mbolivar@leaflabs.com> | 2011-03-30 07:19:13 -0400 |
commit | b13926073f47012d6654b0236f195c4356831fc2 (patch) | |
tree | 6b7e2a0f98ad0dd469855012cd9a10add8c8def4 /docs/source/lang/api/board-values.rst | |
parent | efbc87c64d89bbb367b6d8face6c50edf0eb5e5c (diff) | |
download | librambutan-b13926073f47012d6654b0236f195c4356831fc2.tar.gz librambutan-b13926073f47012d6654b0236f195c4356831fc2.zip |
Board-specific values; corresponding QA test generalizations.
Various board-specific #defines and arrays of pins added.
For the changelog (some of this information predates this commit):
* wirish/boards.h now declares the following arrays of pin numbers:
* boardPWMPins - PWM-capable pins
* boardADCPins - ADC-capable pins
* boardUsedPins - pins already in use, e.g. BOARD_BUTTON_PIN
It also declares a bool boardUsesPin(uint8 pin) function for
convenient testing of whether a pin is in use.
* wirish/boards/*.h now define:
* BOARD_USART1_TX_PIN
* BOARD_USART1_RX_PIN
* BOARD_USART2_TX_PIN
* BOARD_USART2_RX_PIN
* BOARD_USART3_TX_PIN
* BOARD_USART3_RX_PIN
* BOARD_NR_GPIO_PINS (renamed from NR_GPIO_PINS)
* BOARD_NR_USARTS (renamed from NR_USARTS)
* BOARD_NR_PWM_PINS
* BOARD_NR_ADC_PINS
* BOARD_NR_USED_PINS
* wirish/boards/maple_native.h now defines:
* BOARD_UART4_TX_PIN
* BOARD_UART4_RX_PIN
* BOARD_UART5_TX_PIN
* BOARD_UART5_RX_PIN
(Unfortunately, wirish/boards/maple_RET6.h cannot, since at least
one of the UART4/UART5 pins are used already; this will require layout
changes for a wide-release Maple form factor RET6 board).
* wirish/boards/*.cpp all include the corresponding array definitions.
They all live in flash by default, thanks to the new __FLASH__ macro
in wirish/wirish_types.h, which is a synonym for the existing __attr_flash
#define in libmaple/libmaple_types.h.
The documentation was updated to include this information. It also
gained various FIXME/TODO comments related to its generalization
across boards.
The quality assurance-related examples (examples/qa-slave-shield.cpp
and examples/test-session.cpp) now make heavy use of board-specific
values to ensure portability.
Diffstat (limited to 'docs/source/lang/api/board-values.rst')
-rw-r--r-- | docs/source/lang/api/board-values.rst | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/docs/source/lang/api/board-values.rst b/docs/source/lang/api/board-values.rst new file mode 100644 index 0000000..367adbb --- /dev/null +++ b/docs/source/lang/api/board-values.rst @@ -0,0 +1,155 @@ +.. _lang-board-values: + +Board-Specific Constants +======================== + +There are a number of board-specific values: constants or variables +which are different depending on which LeafLabs board you have. + +This page lists and documents the board-specific values. You should +use these when appropriate in your own programs. This will help make +it easier to share your code with other people who have different +boards. Some example usages are given :ref:`below +<lang-board-values-examples>`. + +.. contents:: Contents + :local: + +Constants +--------- + +- ``CYCLES_PER_MICROSECOND``: Number of CPU cycles per microsecond on + your board. + +.. _lang-board-values-but: + +- ``BOARD_BUTTON_PIN``: Pin connected to the built-in button (labeled + "BUT" on your board's silkscreen). + +.. _lang-board-values-led: + +- ``BOARD_LED_PIN``: Pin connected to the built-in LED. + +- ``BOARD_NR_GPIO_PINS``: Total number of :ref:`GPIO pins <gpio>` that + are broken out to headers. Some of these might already be connected + to external hardware (like the built-in LED and button). To find + out if a pin is in use, see :ref:`boardUsesPin() + <lang-boardusespin>` (and also :ref:`boardUsedPins + <lang-board-values-used-pins>`). + +.. _lang-board-values-nr-pwm-pins: + +- ``BOARD_NR_PWM_PINS``: Total *number* of GPIO pins that can be used + for :ref:`PWM <pwm>`. The actual *pins* that can do PWM are in the + :ref:`boardPWMPins <lang-board-values-pwm-pins>` array. + +.. _lang-board-values-nr-adc-pins: + +- ``BOARD_NR_ADC_PINS``: Total number of GPIO pins that can be used + for :ref:`analog-to-digital conversion <adc>`. The actual pins that + can do ADC conversion are in the :ref:`boardADCPins + <lang-board-values-adc-pins>` array. + +.. _lang-board-values-nr-used-pins: + +- ``BOARD_NR_USED_PINS``: Total number of GPIO pins that are already + connected to some external hardware (like a built-in LED) on the + board. The actual pins that that are already used are in the + :ref:`boardUsedPins <lang-board-values-used-pins>` array. To see if + a pin is already in use, use the :ref:`boardUsesPin() + <lang-boardusespin>` function. + +.. _lang-board-values-usart: + +- USART (serial port) related constants: + + * ``BOARD_USART1_TX_PIN``, ``BOARD_USART2_TX_PIN``, ``BOARD_USART3_TX_PIN``: + TX pins for the 3 USARTS. + + * ``BOARD_USART1_RX_PIN``, ``BOARD_USART2_RX_PIN``, ``BOARD_USART3_RX_PIN``: + RX pins for the 3 USARTS. + + * ``BOARD_UART4_TX_PIN``, ``BOARD_UART5_TX_PIN``: TX pins for + UARTs 4 and 5 (high-density boards like Maple Native only). + + * ``BOARD_UART4_RX_PIN``, ``BOARD_UART5_RX_PIN``: RX pins for + UARTs 4 and 5 (high-density boards like Maple Native only). + + * ``BOARD_NR_USARTS``: Number of serial ports on the board. This + number includes UARTs 4 and 5 if they are available. + +.. _lang-board-values-pwm-pins: +.. _lang-board-values-adc-pins: +.. _lang-board-values-used-pins: + +Pin Arrays +---------- + +Some :ref:`arrays <lang-array>` of pin numbers are available which you +can use to find out certain important information about a given pin. + +.. TODO add links to the board-specific hardware information on what +.. are in these arrays + +- ``boardPWMPins``: Pin numbers of each pin capable of :ref:`PWM + <pwm>` output, using :ref:`pwmWrite() <lang-pwmwrite>`. The total + number of these pins is :ref:`BOARD_NR_PWM_PINS + <lang-board-values-nr-pwm-pins>`. + +- ``boardADCPins``: Pin numbers of each pin capable of :ref:`ADC + <adc>` conversion, using :ref:`analogRead() <lang-analogread>`. The + total number of these pins is :ref:`BOARD_NR_ADC_PINS + <lang-board-values-nr-adc-pins>`. + +- ``boardUsedPins``: Pin numbers of each pin that, by default, is used + for some special purpose by the board. The total number of these + pins is :ref:`BOARD_NR_USED_PINS <lang-board-values-nr-used-pins>`. + To check if a pin is used for a special purpose, use + :ref:`boardUsesPin() <lang-boardusespin>`. + +.. _lang-board-values-examples: + +Examples +-------- + +:ref:`BOARD_LED_PIN <lang-board-values-led>` On the Maple, the +built-in LED is connected to pin 13. On the Maple Mini, however, it +is connected to pin 33. You can write a "blinky" program that works +on all LeafLabs boards using ``BOARD_LED_PIN`` and :ref:`toggleLED() +<lang-toggleled>`:: + + void setup() { + pinMode(BOARD_LED_PIN, OUTPUT); + } + + void loop() { + toggleLED(); + delay(100); + } + +:ref:`BOARD_BUTTON_PIN <lang-board-values-but>`: Similarly, you can +write a single program that prints a message whenever the button is +pressed which will work on all LeafLabs boards using +``BOARD_BUTTON_PIN`` and :ref:`isButtonPressed() +<lang-isbuttonpressed>`:: + + void setup() { + pinMode(BOARD_BUTTON_PIN, INPUT); + } + + void loop() { + if (isButtonPressed()) { + SerialUSB.println("You pressed the button!"); + } + } + +See Also +-------- + +- :ref:`lang-boardusespin` +- :ref:`lang-isbuttonpressed` +- :ref:`lang-waitforbuttonpress` +- :ref:`lang-pinmode` +- :ref:`lang-toggleled` +- :ref:`lang-analogread` +- :ref:`lang-pwmwrite` |