47 lines
3.1 KiB
Plaintext
47 lines
3.1 KiB
Plaintext
[video member=miotatsu stream_platform=twitch project=riscy title="Studying the LED Fade Demo Code" vod_platform=youtube id=dQUKjsJpRF8 annotator=Miblo]
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[0:07][Recap and set the stage for the day]
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[1:46][Learn the LED colour fading logic in led_fade.c][:peripheral :research]
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[4:33][Consider investing in a second webcam for the HiFive1]
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[5:56][Upload led_fade.c to the HiFive1 and :run it to eyeball the LED fading]
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[8:01][Confirm that it is doing the logic we expected]
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[8:47][Determine to understand how the PWM1_REG() calls manipulate the PWM Configuration Register[ref
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site="SiFive Developers"
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page="Platform Reference Manual"
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url=https://www.sifive.com/documentation/freedom-soc/freedom-e300-platform-reference-manual/]][:peripheral :research]
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[17:02][Marry up the register offsets and constants defined in devices/pwm.h with the documentation[ref
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site="SiFive Developers"
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page="Platform Reference Manual"
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url=https://www.sifive.com/documentation/freedom-soc/freedom-e300-platform-reference-manual/]][:peripheral :research]
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[25:23][Consult the Freedom E310-G000 Manual[ref
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site="SiFive Developers"
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page="Freedom E310-G000 Manual"
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url=https://www.sifive.com/documentation/chips/freedom-e310-g000-manual/] for the base address of the config register][:peripheral :research]
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[28:31][Determine that we are sending three different signals, one for each LED channel[ref
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site="SiFive Developers"
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page="Freedom E310-G000 Manual"
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url=https://www.sifive.com/documentation/chips/freedom-e310-g000-manual/]][:peripheral :research]
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[35:03][Read the PWM1_REG() macro and marry up the defined PWM1_BASE_ADDR with the documentation[ref
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site="SiFive Developers"
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page="Freedom E310-G000 Manual"
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url=https://www.sifive.com/documentation/chips/freedom-e310-g000-manual/]][:research]
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[38:00][Come to understand how the PWM1_REG() calls manipulate the low 16 bits of the PWM Compare Register[ref
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site="SiFive Developers"
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page="Platform Reference Manual"
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url=https://www.sifive.com/documentation/freedom-soc/freedom-e300-platform-reference-manual/]][:peripheral :research]
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[50:32][Learn that pwmcmp0 sets the width of the duty cycle and that pwmcount resets to zero at the end of every PWM cycle[ref
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site="SiFive Developers"
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page="Platform Reference Manual"
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url=https://www.sifive.com/documentation/freedom-soc/freedom-e300-platform-reference-manual/]][:peripheral :research]
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[52:56][Go over the PWM Compare Registers another time[ref
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site="SiFive Developers"
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page="Platform Reference Manual"
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url=https://www.sifive.com/documentation/freedom-soc/freedom-e300-platform-reference-manual/]][:peripheral :research]
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[55:54][Note that the signal is high most of the time[ref
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site="SiFive Developers"
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page="Platform Reference Manual"
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url=https://www.sifive.com/documentation/freedom-soc/freedom-e300-platform-reference-manual/]][:peripheral :research]
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[58:37][Think about the logic of those PWM1_REG() calls][:blackboard :peripheral :research]
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[1:02:38][Determine to draw out the LED's waveform]
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[1:03:23][We're out of time for today]
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[/video]
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