arduino language reference nearing completion, properly CC-BY-SA 3.0 attributed

8 files changed, 154 insertions, 24 deletions

diff --git a/wirish/ext_interrupts.h b/wirish/ext_interrupts.h
index 80e2e9e..d44978a 100644
--- a/wirish/ext_interrupts.h
+++ b/wirish/ext_interrupts.h
@@ -34,7 +34,7 @@
 #define _EXT_INTERRUPTS_H_
 
 /**
- * The kind transition on an external pin which should trigger an
+ * The kind of transition on an external pin which should trigger an
  * interrupt.
  */
 typedef enum ExtIntTriggerMode_ {
@@ -56,13 +56,16 @@ extern "C"{
  *
  *  The interrupt will be triggered on a given transition on the pin,
  *  as specified by the mode parameter.  The handler runs in interrupt
- *  context.
+ *  context.  The new handler will replace whatever handler is
+ *  currently registered for the pin, if any.
  *
  *  @param pin Maple pin number
  *  @param handler Function to run upon external interrupt trigger.
+ *  The handler should take no arguments, and have void return type.
  *  @param mode Type of transition to trigger on, e.g. falling, rising, etc.
  *
  *  @sideeffect Registers a handler
+ *  @see detachInterrupt()
  */
 void attachInterrupt(uint8 pin, voidFuncPtr handler, ExtIntTriggerMode mode);
 
@@ -70,6 +73,7 @@ void attachInterrupt(uint8 pin, voidFuncPtr handler, ExtIntTriggerMode mode);
  * @brief Disable any registered external interrupt.
  * @param pin Maple pin number
  * @sideeffect unregisters external interrupt handler
+ * @see attachInterrupt()
  */
 void detachInterrupt(uint8 pin);
 
diff --git a/wirish/io.h b/wirish/io.h
index f82e414..f01efcb 100644
--- a/wirish/io.h
+++ b/wirish/io.h
@@ -148,13 +148,17 @@ uint32 digitalRead(uint8);
 
 /**
  * Read an analog value from pin.  This function blocks during ADC
- * conversion.  The pin must have its mode set to INPUT_ANALOG.
+ * conversion, and has 12 bits of resolution.  The pin must have its
+ * mode set to INPUT_ANALOG.  Ignoring function call overhead,
+ * conversion time is 55.5 cycles.
  *
- * @param pin Pin to read from. One of: 0-38 (pin numbers as labeled
- *            on silkscreen), or D0-D38 (symbols for same)
- * @return ADC-converted voltage, in the range 0--4095, inclusive.
+ * @param pin Pin to read from. One of: 0, 1, 2, 3, 10, 11, 12, 13,
+ * 15, 16, 17, 18, 19, 20, 27, 28.
+
+ * @return ADC-converted voltage, in the range 0--4095, inclusive
+ * (i.e. a 12-bit ADC conversion).
+
  * @see pinMode()
- * @see analogReference()
  */
 uint32 analogRead(uint8 pin);
 
diff --git a/wirish/pwm.c b/wirish/pwm.c
index 0bf27aa..dc5cfab 100644
--- a/wirish/pwm.c
+++ b/wirish/pwm.c
@@ -46,5 +46,3 @@ void pwmWrite(uint8 pin, uint16 duty_cycle) {
 
     timer_pwm_write_ccr(ccr, duty_cycle);
 }
-
-
diff --git a/wirish/pwm.h b/wirish/pwm.h
index 6d0ddaf..d0bc9e0 100644
--- a/wirish/pwm.h
+++ b/wirish/pwm.h
@@ -35,15 +35,18 @@
 extern "C"{
 #endif
 
+/**
+ * As a convenience, analogWrite is an alias of pwmWrite to ease
+ * porting Arduino code.  However, period and duty will have to be
+ * recalibrated.
+ */
 #define analogWrite pwmWrite
 
 /**
- * Set the PWM duty.
+ * Set the PWM duty on the given pin.
  *
  * User code is expected to determine and honor the maximum value
- * (based on the configured period). As a convenience, analogWrite is
- * an alias of pwmWrite to ease porting Arduino code, though period
- * and duty will have to be recalibrated
+ * (based on the configured period).
  */
 void pwmWrite(uint8 pin, uint16 duty_cycle);
 
diff --git a/wirish/time.c b/wirish/time.c
index 3a48197..c0a0649 100644
--- a/wirish/time.c
+++ b/wirish/time.c
@@ -43,7 +43,6 @@ void delayMicroseconds(uint32 us) {
 
     /* fudge for function call overhead  */
     us--;
-    int x = 4;
     asm volatile("   mov r0, %[us]          \n\t"
                  "1: subs r0, #1            \n\t"
                  "   bhi 1b                 \n\t"
diff --git a/wirish/time.h b/wirish/time.h
index fad47a4..18aef9a 100644
--- a/wirish/time.h
+++ b/wirish/time.h
@@ -23,7 +23,8 @@
  *****************************************************************************/
 
 /**
- *  @brief Timing and delay functions.
+ * @file time.h
+ * @brief Timing and delay functions.
  */
 
 #ifndef _TIME_H
@@ -41,12 +42,20 @@ extern "C"{
 
 extern volatile uint32 systick_timer_millis;
 
-/* time in milliseconds since boot  */
+/**
+ * Returns time (in milliseconds) since the beginning of program
+ * execution. On overflow, restarts at 0.
+ * @see micros()
+ */
 static inline uint32 millis(void) {
     return systick_timer_millis;
 }
 
-/* Time in microseconds since boot  */
+/**
+ * Returns time (in microseconds) since the beginning of program
+ * execution.  On overflow, restarts at 0.
+ * @see millis()
+ */
 static inline uint32 micros(void) {
     uint32 ms;
     uint32 cycle_cnt;
@@ -67,7 +76,28 @@ static inline uint32 micros(void) {
     return res;
 }
 
+/**
+ * Delay for at least the given number of milliseconds.
+ *
+ * Interrupts, etc. may cause the actual number of milliseconds to
+ * exceed ms.  However, this function will return no less than ms
+ * milliseconds from the time it is called.
+ *
+ * @param ms the number of milliseconds to delay.
+ * @see delayMicroseconds()
+ */
 void delay(unsigned long ms);
+
+/**
+ * Delay for at least the given number of microseconds.
+ *
+ * Interrupts, etc. may cause the actual number of microseconds to
+ * exceed us.  However, this function will return no less than us
+ * microseconds from the time it is called.
+ *
+ * @param us the number of microseconds to delay.
+ * @see delay()
+ */
 void delayMicroseconds(uint32 us);
 
 #ifdef __cplusplus
diff --git a/wirish/wirish_digital.c b/wirish/wirish_digital.c
index aa22196..d7da81f 100644
--- a/wirish/wirish_digital.c
+++ b/wirish/wirish_digital.c
@@ -31,7 +31,7 @@
 
 void pinMode(uint8 pin, WiringPinMode mode) {
     uint8 outputMode;
-    uint32 pwm = 0;
+    boolean pwm = false;
 
     if (pin >= NR_GPIO_PINS) {
         return;
@@ -59,11 +59,11 @@ void pinMode(uint8 pin, WiringPinMode mode) {
         break;
     case PWM:
         outputMode = GPIO_MODE_AF_OUTPUT_PP;
-        pwm = 1;
+        pwm = true;
         break;
     case PWM_OPEN_DRAIN:
         outputMode = GPIO_MODE_AF_OUTPUT_OD;
-        pwm = 1;
+        pwm = true;
         break;
     default:
         ASSERT(0);
diff --git a/wirish/wirish_math.h b/wirish/wirish_math.h
index 4543c1b..9578eb4 100644
--- a/wirish/wirish_math.h
+++ b/wirish/wirish_math.h
@@ -22,6 +22,11 @@
  * THE SOFTWARE.
  *****************************************************************************/
 
+/**
+ * @file wirish_math.h
+ * @brief Includes cmath; provides Arduino-compatible math routines.
+ */
+
 #ifndef _WIRING_MATH_H_
 #define _WIRING_MATH_H_
 
@@ -29,10 +34,53 @@
 
 #ifdef __cplusplus
 
-void randomSeed(unsigned int);
-long random(long);
-long random(long, long);
-long map(long, long, long, long, long);
+/**
+ * @brief Initialize the pseudo-random number generator.
+ * @param seed the number used to initialize the seed; cannot be zero.
+ */
+void randomSeed(unsigned int seed);
+
+/**
+ * @brief Generate a pseudo-random number with upper bound.
+ * @param max An upper bound on the returned value, exclusive.
+ * @return A pseudo-random number in the range [0,max).
+ * @see randomSeed()
+ */
+long random(long max);
+
+/**
+ * @brief Generate a pseudo-random number with lower and upper bounds.
+ * @param min Lower bound on the returned value, inclusive.
+ * @param max Upper bound on the returned value, exclusive.
+ * @return A pseudo-random number in the range [min, max).
+ * @see randomSeed()
+ */
+long random(long min, long max);
+
+/**
+ * @brief Remap a number from one range to another.
+ *
+ * That is, a value equal to fromStart gets mapped to toStart, a value
+ * of fromEnd to toEnd, and other values are mapped proportionately.
+ *
+ * Does not constrain value to lie within [fromStart, fromEnd].
+ *
+ * If a "start" value is larger than its corresponding "end", the
+ * ranges are reversed, so map(n, 1, 10, 10, 1) would reverse the
+ * range [1,10].
+ *
+ * Negative numbers may appear as any argument.
+ *
+ * @param value the value to map.
+ * @param fromStart the beginning of the value's current range.
+ * @param fromEnd the end of the value's current range.
+ * @param toStart the beginning of the value's mapped range.
+ * @param toEnd the end of the value's mapped range.
+ * @return the mapped value.
+ */
+long map(long value,
+         long fromStart, long fromEnd,
+         long toStart, long toEnd);
 
 #define PI          3.1415926535897932384626433832795
 #define HALF_PI     1.5707963267948966192313216916398
@@ -56,4 +104,48 @@ long map(long, long, long, long, long);
 
 #endif
 
+/* Following are duplicate declarations (with Doxygen comments) for
+ * some of the math.h functions; this is for the convenience of the
+ * Sphinx docs.
+ */
+
+/**
+ * Compute the cosine of an angle, in radians.
+ * @param x The radian measure of the angle.
+ * @return The cosine of x.  This value will be between -1 and 1.
+ */
+double cos(double x);
+
+/**
+ * Compute the sine of an angle, in radians.
+ * @param x The radian measure of the angle.
+ * @return The sine of x.  This value will be between -1 and 1.
+ */
+double sin(double x);
+
+/**
+ * Compute the tangent of an angle, in radians.
+ * @param x The radian measure of the angle.
+ * @return The tangent of x.  There are no limits on the return value
+ * of this function.
+ */
+double tan(double x);
+
+/**
+ * Compute the square root of a number.
+ * @param x The number whose square root to find.  This value cannot
+ * be negative.
+ * @return The square root of x.  The return value is never negative.
+ */
+double sqrt(double x);
+
+/**
+ * Compute an exponentiation.
+ * @param x the base. This value cannot be zero if y <= 0.  This value
+ * cannot be negative if y is not an integral value.
+ * @param y the exponent.
+ * @return x raised to the power y.
+ */
+double pow(double x, double y);
+
 #endif