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| author | Damien George <damien.p.george@gmail.com> | 2016-01-29 23:06:13 +0000 |
|---|---|---|
| committer | Damien George <damien.p.george@gmail.com> | 2016-01-29 23:06:13 +0000 |
| commit | 0f87a010e331c42fe020ad2803e5a1b67065b87a (patch) | |
| tree | 65a3d3d0ade3350f6823284c9d43ace30f37dc9d | |
| parent | a8a4b01af6501ff7ab61b251fc30fcf8a286f8d1 (diff) | |
| download | micropython-0f87a010e331c42fe020ad2803e5a1b67065b87a.tar.gz micropython-0f87a010e331c42fe020ad2803e5a1b67065b87a.zip | |
docs: Update to say that Timer(3) is free, and detail LED intensity.
| -rw-r--r-- | docs/library/pyb.LED.rst | 6 | ||||
| -rw-r--r-- | docs/library/pyb.Timer.rst | 12 |
2 files changed, 14 insertions, 4 deletions
diff --git a/docs/library/pyb.LED.rst b/docs/library/pyb.LED.rst index 461ea57d31..aeeb75b8f1 100644 --- a/docs/library/pyb.LED.rst +++ b/docs/library/pyb.LED.rst @@ -25,6 +25,12 @@ Methods If no argument is given, return the LED intensity. If an argument is given, set the LED intensity and return ``None``. + *Note:* Only LED(3) and LED(4) can have a smoothly varying intensity, and + they use timer PWM to implement it. LED(3) uses Timer(2) and LED(4) uses + Timer(3). These timers are only configured for PWM if the intensity of the + relevant LED is set to a value between 1 and 254. Otherwise the timers are + free for general purpose use. + .. method:: led.off() Turn the LED off. diff --git a/docs/library/pyb.Timer.rst b/docs/library/pyb.Timer.rst index af28fb6787..d2a299bd29 100644 --- a/docs/library/pyb.Timer.rst +++ b/docs/library/pyb.Timer.rst @@ -37,9 +37,13 @@ class Timer -- control internal timers tim.callback(lambda t: ...) # set callback for update interrupt (t=tim instance) tim.callback(None) # clear callback - *Note:* Timer 3 is reserved for internal use. Timer 5 controls - the servo driver, and Timer 6 is used for timed ADC/DAC reading/writing. - It is recommended to use the other timers in your programs. + *Note:* Timer(2) and Timer(3) are used for PWM to set the intensity of LED(3) + and LED(4) respectively. But these timers are only configured for PWM if + the intensity of the relevant LED is set to a value between 1 and 254. If + the intensity feature of the LEDs is not used then these timers are free for + general purpose use. Similarly, Timer(5) controls the servo driver, and + Timer(6) is used for timed ADC/DAC reading/writing. It is recommended to + use the other timers in your programs. *Note:* Memory can't be allocated during a callback (an interrupt) and so exceptions raised within a callback don't give much information. See @@ -56,7 +60,7 @@ Constructors Construct a new timer object of the given id. If additional arguments are given, then the timer is initialised by ``init(...)``. - ``id`` can be 1 to 14, excluding 3. + ``id`` can be 1 to 14. Methods ------- |