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Diffstat (limited to 'docs/source/lang/api/serialusb.rst')
| -rw-r--r-- | docs/source/lang/api/serialusb.rst | 72 |
1 files changed, 29 insertions, 43 deletions
diff --git a/docs/source/lang/api/serialusb.rst b/docs/source/lang/api/serialusb.rst index 87fa641..ed466f2 100644 --- a/docs/source/lang/api/serialusb.rst +++ b/docs/source/lang/api/serialusb.rst @@ -16,9 +16,8 @@ Introduction In addition to three :ref:`serial ports <lang-serial>`, the Maple's STM32 microprocessor includes a dedicated USB peripheral. This peripheral is used to emulate a regular serial port for use as a -terminal (text read/write). The emulated terminal is relatively slow -and inefficient; it is best for transferring data at regular serial -speeds (kilobaud). +terminal. The emulated terminal is relatively slow; it is best for +transferring data at regular serial speeds (kilobaud). Library access to the emulated serial port is provided through the ``SerialUSB`` object. You can mostly use ``SerialUSB`` as a drop-in @@ -30,14 +29,14 @@ replacement for ``Serial1``, ``Serial2``, and ``Serial3``. This means that if you have a number of calls to one of the ``SerialUSB`` ``write()`` or ``print()`` functions in your code, - and you are not monitoring the emulated on a computer, your program - will run much, much slower than if it is being monitored or totally - disconnected (run off of a battery). + and you are not monitoring ``SerialUSB`` on a computer, your + program will run much slower than if it is being monitored or + totally disconnected (run off of a battery). You can avoid this behavior by :ref:`deciphering the port status - using the DTR and RTS line status <lang-serialusb-safe-print>`; the + using the DTR and RTS line status <lang-serialusb-safe-print>` (the behavior of these control lines is platform dependent and we no - longer interpret them by default. + longer interpret them by default). Library Documentation --------------------- @@ -109,35 +108,26 @@ world!")``. Print the argument's digits over the USB connection, in decimal format. -.. cpp:function:: USBSerial::print(long long n) +.. cpp:function:: USBSerial::print(long n) Print the argument's digits over the USB connection, in decimal format. Negative values will be prefixed with a ``'-'`` character. -.. cpp:function:: USBSerial::print(unsigned long long n) +.. cpp:function:: USBSerial::print(unsigned long n) Print the argument's digits over the USB connection, in decimal format. -.. _lang-serial-print-n-base: +.. cpp:function:: USBSerial::print(long n, int base) -.. cpp:function:: USBSerial::print(int n, int base) - - Print the digits of ``n`` over USB, in base ``base``. The ``base`` - value 2 corresponds to binary, 8 to octal, 10 to decimal, and 16 to - hexadecimal (you can also use the symbolic constants ``BIN``, - ``OCT``, ``DEC``, ``HEX``). If ``base`` is 10, negative values - will be prefixed with a ``'-'`` character (otherwise, ``n`` will be - interpreted as an unsigned quantity). - -.. cpp:function:: HardwareSerial::print(long long n, int base) - - Same behavior as the above :ref:`print(int n, int base) - <lang-serialusb-print-n-base>`, except with 64-bit values. + Print the digits of ``n`` over the USB connection, in base ``base`` + (which may be between 2 and 16). The ``base`` value 2 corresponds + to binary, 8 to octal, 10 to decimal, and 16 to hexadecimal. + Negative values will be prefixed with a ``'-'`` character. .. cpp:function:: USBSerial::print(double n) - Print ``n``, accurate to 6 digits after the decimal point. + Print ``n``, accurate to 2 digits after the decimal point. .. _lang-serialusb-println: @@ -161,19 +151,15 @@ world!")``. Like ``print(n)``, followed by ``"\r\n"``. -.. cpp:function:: USBSerial::println(long long n) +.. cpp:function:: USBSerial::println(long n) Like ``print(n)``, followed by ``"\r\n"``. -.. cpp:function:: USBSerial::println(unsigned long long n) +.. cpp:function:: USBSerial::println(unsigned long n) Like ``print(n)``, followed by ``"\r\n"``. -.. cpp:function:: USBSerial::println(int n, int base) - - Like ``print(n, b)``, followed by ``"\r\n"``. - -.. cpp:function:: USBSerial::println(long long n, int base) +.. cpp:function:: USBSerial::println(long n, int base) Like ``print(n, b)``, followed by ``"\r\n"``. @@ -224,7 +210,7 @@ running from battery, or connected but not monitored. You may need to experiment with the DTR/RTS logic for your platform and device configuration. :: - #define LED_PIN 13 + #define LED_PIN BOARD_LED_PIN void setup() { /* Set up the LED to blink */ @@ -232,22 +218,22 @@ configuration. :: } void loop() { - // LED will stay off if we are disconnected; - // will blink quickly if USB is unplugged (battery etc) + // LED will stay off if we are disconnected, and will blink + // quickly if USB is unplugged (battery power, etc.). if(SerialUSB.isConnected()) { digitalWrite(LED_PIN, 1); } delay(100); - // If this logic fails to detect if bytes are going to - // be read by the USB host, then the println() will fully - // many times, causing a very slow LED blink. - // If the characters are printed and read, the blink will - // only slow a small amount when "really" connected, and fast - // when the virtual port is only configured. + // If this logic fails to detect if bytes are going to be read + // by the USB host, then the println() take a long time, + // causing a very slow LED blink. If the characters are + // printed and read, the blink will only slow a small amount + // when "really" connected, and will be fast fast when the + // virtual port is only configured. if(SerialUSB.isConnected() && (SerialUSB.getDTR() || SerialUSB.getRTS())) { - for(int i=0; i<10; i++) { - SerialUSB.println(123456,BIN); + for(int i = 0; i < 10; i++) { + SerialUSB.println(123456, BIN); } } digitalWrite(LED_PIN, 0); |