VL53L8CX DEEP SLEEP MODE

[ali6]

Hello,

I'm trying to set up the deep sleep mode for VL53L8CX using NUCLEO L476RG board

so as described in the datasheet that it can operates in 3 different states:
• Wake-up: The device is set in HP idle (high power), waiting for instructions.
• Sleep: The device is set in LP idle (low power), the low power state. The device cannot be used until set in
wake-up mode. This mode retains the firmware and the configuration.
• Deep sleep: The device is set in ultra-low power. In this mode, the sensor consumes a few microamps of
current. However, the firmware, configuration, and calibration data are completely lost. The user needs to
set the device in wake-up mode and reconfigure the sensor to start streaming.

 

But the only result i'm getting using api functions are wake-up and sleep mode but not the deep sleep one

Can you please help me to get it working

[John E KVAM]

According to the datasheet, the power states are:

The L5 referenced a Ultra low power idle mode. Perhaps that was what you were looking for.

Between ranges you should be in LP idle state waiting for a command. I believe you can drop the LPn pin to turn off the I2C interface which saves a bit. I did not see in the datasheet if that retains the memory or not. But the chart above seems to indicate that it does. It's not very clear, however. 

 

[ali6]

Sir John,

Excuse me if I am mistaken, but according to the datasheet, using Low Power (LP) mode, the current consumption should average in the microamp range. However, when using the VL53L8CX sensor in sleep mode as defined in the API, I am measuring an average current consumption of 1.6mA. This result does not align with the theoretical value described in the datasheet.

Is there a specific way to drive the device into the 'real sleep mode' which I am not aware of?

[John E KVAM]

Apparently, it was removed and then put back when people complained.

Remember the Deep Sleep mode is basically 'off'. One must re-initialize the chip when waking it back up.

Wownload the latest STSW-IMG040 and search the function:

vl53l8cx_set_power_mode()

You will note there is a VL53L8CX_POWER_MODE_DEEP_SLEEP option.

- john

[ali6]

Sir John, thank you very much for this information. I have successfully set up the ultra low power mode, and the sensor is now consuming only a few microamps.

However, I have a question regarding the autonomous mode set to 1 Hz as described in the datasheet. According to the datasheet, between each measurement, the device should be in sleep mode, resulting in an average consumption of around 1.6 mA. However, I am observing an average consumption of 5.21 mA in this mode, as shown in the captures below. Could you please advise if there is a specific method to achieve the expected consumption between measurements?