search

thotro / arduino-dw1000

A library that offers functionality to use Decawave's DW1000 chips/modules with Arduino.
Apache License 2.0
516 stars 288 forks source link

current consumption in deepSleep mode #254

Open vat1 opened 6 years ago

vat1 commented 6 years ago

I've measured current consumption from 5 mA on the DWM1000 in sleep time (DW1000.deepSleep();). It's to more then 100 nA mentioned in DW1000 datasheet. Have someone better result or ideas how to decrease it. thanks in advance!

werty37 commented 6 years ago

DWM1000 datasheet mentions 200nA for deep sleep mode and 550nA for sleep mode. But 5mA in your case seems more than normal. https://www.decawave.com/sites/default/files/dwm1000-datasheet-v1.6.pdf

It would be easier to understand if you post your schematic.

vat1 commented 6 years ago

Thank you for answer!

I'm using the same datasheet "Figure 9: Example DWM1000 Application Circuit" on page 17 and ESP8266 like controller. diagram

werty37 commented 6 years ago

The circuit seems fine. Decawave recommends grounding the wakeup pin, if unused though. You might want to check the void DW1000Class::deepSleep() method. A bunch of registers are getting set there. You can verify if all of register bits are getting set as recommended in the datasheet for deep sleep modes.

https://github.com/thotro/arduino-dw1000/blob/master/src/DW1000.cpp

Also DW1000 User Manual Pg17 says,

In DEEPSLEEP all internal circuitry is powered down with the exception of the always-on memory which can be used to hold the device configuration for restoration on wakeup.

While in DEEPSLEEP power should not be applied to GPIO, SPICLK or SPIMISO pins as this will cause an increase in leakage current.

https://www.decawave.com/sites/default/files/dw1000_user_manual_2.12.pdf

I believe this library does use AON to save the device configuration. Maybe this is what is consuming the 5mA power. I am just speculating here though.

kuek commented 6 years ago

your schematic does work, but its not power efficient. its probably the LDO.

regards, kuek from www.localino.net

seppestas commented 3 years ago

Not sure if anyone is still interested in this issue, but the problem is likely the LDO. It has a quiescent current of 5mA: image This means that even if unloaded, the LDO will typically consume 5mA. Also not that this LDO will not be able to handle the transient currents required by DWM1000 in typical operation.

Having the EXTON pin pulled to GND by R3 is also not ideal. This will prevent the DWM1000 from turning of it's internal DC/DC, which is controlled by the EXTON signal. This will add an additional quiescent current (though not nearly as high as that of the LDO).

Make sure to pull down the SPI MISO and SPI CLK pins as @werty37 mentioned.