Current Consumption Factory FW vs. dwm-simple Example

Wireless Connectivity Ultra-Wideband
1

Hi All,

unfortunately I have come across a problem while testing my own firmware for the DWM1001. In comparison to the Factory Firmware Image, my code consumes around 400µA more in Low Power Mode being IDLE. I have also tested the untouched dwm-simple example upon which I implemented my firmware and it shows the same high current consumption. I have measured the current on the DWM1001-DEV board at J2 with J4 open (current consumption of DWM module only). LEDs are off, BLE is off, Responsive Mode is off and Stationary Detection is off. I am measuring the following values:

UPDATE RATE | FACTORY FW | dwm-simple
100 ms | 2.23 mA | 2.80 mA
200 ms | 1.10 mA | 1.51 mA
10s | 0.01 mA | 0.32 mA

My application requires the lowest update rate and thus the 0.32 mA in IDLE LOW POWER are very critical for battery lifetime compared to the 0.01 mA.
Any idea how to explain the difference in power consumption and how to reduce it in the dwm-simple example?

Thanks and best regards from Germany
Markus

2

320 uA is not a typical DW1000 power usage being well under INIT or IDLE power, so this suggests the DW1000 is being properly put into SLEEP or DEEPSLEEP modes. That means the power is coming from something else, most likely the microcontroller and how it is configured.

Getting low power takes diligence as there are so may ways to cause power usage without realizing it. For example:

Pin pull ups or pull downs left enabled.

Input left floating which goes half voltage.

Internal peripherals left enabled.

Internal clocks still running.

Output contention between devices.

And many others.

The main issue is that there is no obvious way to find these problems other than systematic checking of every possible source of power usage. Building a truly low power system requires systematic care.

Mike Ciholas, President, Ciholas, Inc
3700 Bell Road, Newburgh, IN 47630 USA
mikec@ciholas.com
+1 812 962 9408