diff options
Diffstat (limited to 'docs/esp8266/tutorial/powerctrl.rst')
| -rw-r--r-- | docs/esp8266/tutorial/powerctrl.rst | 61 |
1 files changed, 0 insertions, 61 deletions
diff --git a/docs/esp8266/tutorial/powerctrl.rst b/docs/esp8266/tutorial/powerctrl.rst deleted file mode 100644 index 3502624ab..000000000 --- a/docs/esp8266/tutorial/powerctrl.rst +++ /dev/null @@ -1,61 +0,0 @@ -Power control -============= - -The ESP8266 provides the ability to change the CPU frequency on the fly, and -enter a deep-sleep state. Both can be used to manage power consumption. - -Changing the CPU frequency --------------------------- - -The machine module has a function to get and set the CPU frequency. To get the -current frequency use:: - - >>> import machine - >>> machine.freq() - 80000000 - -By default the CPU runs at 80MHz. It can be change to 160MHz if you need more -processing power, at the expense of current consumption:: - - >>> machine.freq(160000000) - >>> machine.freq() - 160000000 - -You can change to the higher frequency just while your code does the heavy -processing and then change back when it's finished. - -Deep-sleep mode ---------------- - -The deep-sleep mode will shut down the ESP8266 and all its peripherals, -including the WiFi (but not including the real-time-clock, which is used to wake -the chip). This drastically reduces current consumption and is a good way to -make devices that can run for a while on a battery. - -To be able to use the deep-sleep feature you must connect GPIO16 to the reset -pin (RST on the Adafruit Feather HUZZAH board). Then the following code can be -used to sleep and wake the device:: - - import machine - - # configure RTC.ALARM0 to be able to wake the device - rtc = machine.RTC() - rtc.irq(trigger=rtc.ALARM0, wake=machine.DEEPSLEEP) - - # set RTC.ALARM0 to fire after 10 seconds (waking the device) - rtc.alarm(rtc.ALARM0, 10000) - - # put the device to sleep - machine.deepsleep() - -Note that when the chip wakes from a deep-sleep it is completely reset, -including all of the memory. The boot scripts will run as usual and you can -put code in them to check the reset cause to perhaps do something different if -the device just woke from a deep-sleep. For example, to print the reset cause -you can use:: - - if machine.reset_cause() == machine.DEEPSLEEP_RESET: - print('woke from a deep sleep') - else: - print('power on or hard reset') - |