RAK WisBlock nRF power usage

Hi.

I’m using RAK 19007 + 4631 (nRF) for testing/deploying meshtastic.

In router mode, observed “idle” current is constant 100 mA, using LiPo battery. This translates into about 410 mW. Is this normal for RAK platform?

What should one expect in different scenarios like no bt, no screen, no gps, minimum peripherals and so on?

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To answer myself, I tried another device and got considerably smaller power figures, on average about 8-10 mA ie 37 mW.

Earlier high power use persisted even after factory reset, so maybe the hardware is toast.

See if your bootloader is updated to the latest and I run CLIENT on mine. I get around 5-6mA with no GPS in a 3 node network.

I think it is the latest. RAK speaks of 0.4.3 but can’t find a download/release.

UF2 Bootloader 0.4.2 lib/nrfx (v2.0.0) lib/tinyusb (0.10.1-293-gaf8e5a90) lib/uf2 (remotes/origin/configupdate-9-gadbb8c7)
Model: WisBlock RAK4631 Board
Board-ID: WisBlock-RAK4631-Board
Date: Dec  1 2021
SoftDevice: S140 6.1.1

And here it is …

Right. Updated the 0.4.3 bootloder, then factory erase and reflash of meshtastic. Without any post-flash configuration, it still consumes 100 mA. Everything works but it just consumes way too much. I dont think the radios are fried. Anyway, one for the team I guess.

Hmm, well you got me then!

How are you measuring the current?

With normal DMM in series with the lipo battery. Or with DC clamp meter. Same method shows ~8 mA for working board.

Have you tried different combos with your other boards? Such as the core from Broken Assembly replacing the core on Working Assembly. If so what did you observe?

If you have (or can borrow) a thermal camera or vapor flux pen, it would be interesting to see what part(s) are radiating the heat. Do you have either?

Haven’t tried swapping cores yet, I was afraid second one would go bad as well.
I took the core off and then the base board shows ~0 power. Reinserting core goes back to the 100 mA range.

I could use cold spray on it and see what evaporates first, if anything. I dont have any fancy imaging equipment at hand.

Same result with good base on bad core? Near 0 current?
What happens when powering from USB alone?
What is voltage measurement between VDD-GND from either battery or USB power?
Let us know if you can locate a hot spot somehow.

Sorry for the delay, I had no hardware to test on.
Here are some fresh measurements. We can see that whenever bad core is used, the power usage is high, so core is toast. I don’t think there’s much that can be done.

Open V_BAT 4.208 V
Bootloader/UMS mode where possible

bad base:
V_BAT 4.205 V
I_BAT 1.2 mA
P_BAT 4.5 mW
Vdd 0.29 V

good base:
V_BAT 4.206 V
I_BAT 1.27 mA
P_BAT 5.6 mW
Vdd 0 V

bad base + good core:
V_BAT 4.200 V
I_BAT 7.20 mA
P_BAT 28 mW
Vdd 3.31 V

good base + good core:
V_BAT 4.200 V
I_BAT 7.16 mA
P_BAT 28 mW
Vdd 3.31 V

good base + bad core:
V_BAT 4.192 V
I_BAT 107 mA
P_BAT 450 mW
Vdd 3.32 V

bad base + bad core:
V_BAT 4.193 V
I_BAT 106.8 mA
P_BAT 447 mW
Vdd 3.33 V