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Diffstat (limited to 'examples/hwapi/soft_pwm.py')
| -rw-r--r-- | examples/hwapi/soft_pwm.py | 38 |
1 files changed, 0 insertions, 38 deletions
diff --git a/examples/hwapi/soft_pwm.py b/examples/hwapi/soft_pwm.py deleted file mode 100644 index 72291b0ec..000000000 --- a/examples/hwapi/soft_pwm.py +++ /dev/null @@ -1,38 +0,0 @@ -import utime -from hwconfig import LED - - -# Using sleep_ms() gives pretty poor PWM resolution and -# brightness control, but we use it in the attempt to -# make this demo portable to even more boards (e.g. to -# those which don't provide sleep_us(), or provide, but -# it's not precise, like would be on non realtime OSes). -# We otherwise use 20ms period, to make frequency not less -# than 50Hz to avoid visible flickering (you may still see -# if you're unlucky). -def pwm_cycle(led, duty, cycles): - duty_off = 20 - duty - for i in range(cycles): - if duty: - led.on() - utime.sleep_ms(duty) - if duty_off: - led.off() - utime.sleep_ms(duty_off) - - -# At the duty setting of 1, an LED is still pretty bright, then -# at duty 0, it's off. This makes rather unsmooth transition, and -# breaks fade effect. So, we avoid value of 0 and oscillate between -# 1 and 20. Actually, highest values like 19 and 20 are also -# barely distinguishible (like, both of them too bright and burn -# your eye). So, improvement to the visible effect would be to use -# more steps (at least 10x), and then higher frequency, and use -# range which includes 1 but excludes values at the top. -while True: - # Fade in - for i in range(1, 21): - pwm_cycle(LED, i, 2) - # Fade out - for i in range(20, 0, -1): - pwm_cycle(LED, i, 2) |
