Mesh LPN example current consumption

RE: Mesh LPN example current consumption

Heiner — Wed, 21 Aug 2019 18:36:10 GMT

Hi Gerry,

I actually posted a similar question in this thread.

First of all, as Mttrinh mentioned you have to disable RTT and also stop the proxy functionality.

It's described in more detail in the link.

Second, how are you measuring the current?

If you are measuring the current drawn by the Development Kit you might want to take into account, that the MCU which is used for debugging is still consuming 20 uA, even when powered over the external supply. So the 34 uA you are measuring are actually just 14 uA consumed by the nRF52840 and 20 uA consumed by the other MCU. Which you can just remove in your design later.

This is done to maintain the reset button functionality even though I personally think I would rather have the MCU powered off completely.

Hope this helps.

Best,

Heiner

RE: Mesh LPN example current consumption

Gerry — Fri, 12 Jul 2019 08:22:10 GMT

Thanks for your answer, even if that's bad news for us.

I opened a new ticket to find a solution here

RE: Mesh LPN example current consumption

Mttrinh — Thu, 11 Jul 2019 12:46:48 GMT

There are no other mesh examples that can get the nRF52840 into this state. Using Bluetooth Mesh causes higher power consumption than traditional Bluetooth low energy applications. This is mainly due to the need for keeping the radio running constantly. We are still working to improve the power consumption for LPN. I don't think you can get the current consumption as low as 4uA.

RE: Mesh LPN example current consumption

Gerry — Thu, 11 Jul 2019 12:19:10 GMT

Found this here in the infocenter (System ON, full 256 kB RAM retention, wake on RTC)

If not the LPN example, is there an other mesh-example, to get the nRF52840 into this state for a certain time and then wake up periodically with the RTC?

RE: Mesh LPN example current consumption

Mttrinh — Thu, 11 Jul 2019 09:15:59 GMT

Where did you find the information that the LPN have a current og about 4uA?

RE: Mesh LPN example current consumption

Gerry — Thu, 11 Jul 2019 08:38:52 GMT

Hi, thanks I set RTT_INPUT_ENABLED to 0. Still 34uA.

I'm a bit confused, we do not get lower with the LPN example. Is it really not possible to get any lower with a low power node?

RE: Mesh LPN example current consumption

Mttrinh — Wed, 10 Jul 2019 15:25:10 GMT

Search for this define in your project, RTT_INPUT_ENABLED, and set it to 0 to disable it.

RE: Mesh LPN example current consumption

Gerry — Wed, 10 Jul 2019 14:06:35 GMT

Hi,

Sounds interesting. I searched for disabling the RTT input polling, but didn't find that. Can you tell me, how this would be done in the LPN example?

Can it be done commenting this line out:

rtt_input_enable(rtt_input_handler, RTT_INPUT_POLL_PERIOD_MS);

When I do this, I get down to 34uA. If I also disable GATT proxy adv., I get down to 32uA

Schouldn't we see a current of about 4uA with this example?

RE: Mesh LPN example current consumption

Mttrinh — Wed, 10 Jul 2019 12:47:45 GMT

Hi,

I have talked to the Mesh team and 40uA seems to be normal with LPN example. You should disable the RTT input polling to reduce the current. You can also disable GATT proxy advertising to further reduce the current.

RE: Mesh LPN example current consumption

Gerry — Mon, 08 Jul 2019 08:54:48 GMT

Hi,

the multimeter is connected like shown here and here

SW8 = on

SB40 is cut

SW9 = VDD

SW6 = Default

We supply with the built in coin cell. The multimeter is in DC/uA range.

Can you see something wrong in this setup?

RE: Mesh LPN example current consumption

Mttrinh — Wed, 03 Jul 2019 13:48:47 GMT

It might be your measurement setup that is at fault. Could you describe the position of all the switches and how you have connected the multimeter?

Have a look at this post, there is a lot of info that might help.

RE: Mesh LPN example current consumption

Gerry — Mon, 01 Jul 2019 12:03:41 GMT

Yes, unmodified, just compiled it with SES and programmed it to the PCA10056. First with the debugger connected, to see everything works well and then without debugger. I then push button 3 to establish or cancel friendship from time to time, but I never came below 40uA @ 3V

RE: Mesh LPN example current consumption

Mttrinh — Mon, 01 Jul 2019 10:53:26 GMT

Hi,

Yes, the current consumption seems to be high. Are you running an unmodified version of the example? Have you done any modifications?