machine --- 与硬件相关的功能¶
machine 模块包含与特定板上的硬件相关的特定函数。
在这个模块中的大多数功能允许实现直接和不受限制地访问和控制系统上的硬件块（如CPU，定时器，总线等）。
使用不当，会导致故障，死机，你会崩溃，在极端的情况下，硬件损坏。
A note of callbacks used by functions and class methods of machine module:
all these callbacks should be considered as executing in an interrupt context.
This is true for both physical devices with IDs >= 0 and "virtual" devices
with negative IDs like -1 (these "virtual" devices are still thin shims on
top of real hardware and real hardware interrupts). See isr_rules.
中断功能¶
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machine.disable_irq()¶ Disable interrupt requests. Returns the previous IRQ state which should be considered an opaque value. This return value should be passed to the
enable_irqfunction to restore interrupts to their original state, beforedisable_irqwas called.
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machine.enable_irq(state)¶ Re-enable interrupt requests. The
stateparameter should be the value that was returned from the most recent call to thedisable_irqfunction.
有效的相关功能¶
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machine.freq()¶ Returns CPU frequency in hertz.
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machine.idle()¶ Gates the clock to the CPU, useful to reduce power consumption at any time during short or long periods. Peripherals continue working and execution resumes as soon as any interrupt is triggered (on many ports this includes system timer interrupt occurring at regular intervals on the order of millisecond).
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machine.sleep()¶ Stops the CPU and disables all peripherals except for WLAN. Execution is resumed from the point where the sleep was requested. For wake up to actually happen, wake sources should be configured first.
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machine.deepsleep()¶ Stops the CPU and all peripherals (including networking interfaces, if any). Execution is resumed from the main script, just as with a reset. The reset cause can be checked to know that we are coming from
machine.DEEPSLEEP. For wake up to actually happen, wake sources should be configured first, likePinchange orRTCtimeout.
更多功能¶
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machine.unique_id()¶ Returns a byte string with a unique identifier of a board/SoC. It will vary from a board/SoC instance to another, if underlying hardware allows. Length varies by hardware (so use substring of a full value if you expect a short ID). In some MicroPython ports, ID corresponds to the network MAC address.
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machine.time_pulse_us(pin, pulse_level, timeout_us=1000000)¶ Time a pulse on the given pin, and return the duration of the pulse in microseconds. The pulse_level argument should be 0 to time a low pulse or 1 to time a high pulse.
If the current input value of the pin is different to pulse_level, the function first (*) waits until the pin input becomes equal to pulse_level, then (**) times the duration that the pin is equal to pulse_level. If the pin is already equal to pulse_level then timing starts straight away.
The function will return -2 if there was timeout waiting for condition marked (*) above, and -1 if there was timeout during the main measurement, marked (**) above. The timeout is the same for both cases and given by timeout_us (which is in microseconds).