Power Save - Deep Sleep for DHT and LCD


  • AmebaD [AMB21 / AMB22 / AMB23 / BW16] x 1

  • DHT11 or DHT22 or DHT21 x 1

  • LCD I2C screen x 1



Ameba-D supports low power modes which are deepsleep mode. Deepsleep mode turns off most of the system power domain. The power consumptions of core module in DeepSleep Mode is around 7uA to 8uA compare to normal state around 22mA. This example gives demo of system switch between “working” and “sleep”(power save).Using DHT sensor to read data and display on LCD screen when system is awake. After 5 seconds system auto enter DeepSleep Mode for power save. System will wake up by wakeup source.( Aon timer, Aon Pins or RTC timer).

Open “File” “Examples” “AmebaPowerSave” “DeepSleep_DHT_LCD_Example”


Set condition values as picture below.
DS_WAKEUP_SOURCE is used to set the wake-up source, user can chose 3 wake up sources now,
Using AON Timer as wakeup source
AON timer can be set from 0 to 32760000 range (unit ms) by AON_TIMER_SLEEP_DURATION
Using AON GPIO pins as wakeup source
For AMB21, there are 5 pins that can be set as AON pins and active high for wakeup, GPIOA25(D16), GPIOA26(D17), GPIOA21(D26), GPIOA20(D27), GPIOA(D28).
For AMB23, there are 8 pins that can be set as AON pins and active high for wakeup, GPIOA12(D9), GPIOA13(D10), GPIOA14(D11), GPIOA15(D12), GPIOA16(D13), GPIOA18(D15), GPIOA19(D16), GPIOA21(D18).
For BW16, there is only 6 pins that can be set as AON pin and active high for wakeup, GPIOA_25 (D7), GPIOA_26 (D8), GPIOA_15 (D9), GPIOA_14 (D10), GPIOA_13 (D11), GPIOA_12 (D12).
These AON pins can be set by using SET_AON_GPIO_WAKEUP_GPIOA25 or the pin that you want to use as shown in the picture below.


Using RTC Timer as wakeup source
RTC timer wakeup system is by setting alarm. The alarm has 4 values, day, hour, min and sec. All 4 values can be set by DS_RTC_ALARM_DAY, DS_RTC_ALARM_HOUR, DS_RTC_ALARM_MIN, and DS_RTC_ALARM_SEC
DHTPIN is used to set DHT sensor data pin. User can choose any GPIO pins.
DHTTYPE is used to set DHT sensor type. (DHT11, DHT22 and DHT33)


When finished the condition values setting, system will run and switch between normal working mode and deepsleep mode controlled by wakeup source. LCD screen will display the temperature and humidity data measured from DHT sensor when system is awake.

Code Reference

Please refer to the API Documents PowerSave section for detail description of all API.