Xenon power consumption


#1

I am doing a bit of product idea generation.

I am looking into how long a xenon driving an e-paper display (so virtually no power consumption) could in theory operate if spending a large part of its time sleeping, waking to receive any updates for the display, running on a 1200mAh LiPo battery [could use a bigger capacity battery].

It is correct that the sleep functionality has not been implemented for the mesh devices? If yes, what is the likely timescale until that functionality gets in a development sprint?


#2

I don’t have a xenon (yet) but I do have a photon (one with sonar attached and one with temp attached) and I have this that I use to measure power consumption. https://smile.amazon.com/gp/product/B01CVMAK2M/

When I get my xenon I can take a look at its power usage.

LMK if you want details on the photon power consumption!

Tim


#3

Here is the power draw on the Xenon when its connected to Mesh and flashing green.


#4

I wonder if firmware versions impact power consumption? My photon is running 0.8.0-rc.11 and shows 5.14V/.09A - I think I may need to test the same setup with different firmware/os versions :thinking:


#5

The Photon will use considerably more power because of the STM32F205 processor and the Wi-Fi radio.

The Xenon will go even lower than that once power saving modes are implemented. The nRF52840 module (MCU + mesh and BLE) is designed for low-power operation.


#6

Note - I am connected to WiFi and sending data every 5 minutes as well as I have a SHT31-D temp sensor attached via I2C.


#7

@tchaffee, you can’t really compare a Photon and a Xenon in terms of power consumption. The Photon uses WiFi which is not designed for low power. It also runs an STM32F205 at 120MHz. The Xenon, on the other hand, uses an nRF82540 MCU (64MHz) designed for low power operation with communications based on 6lowpan and Thread which are low power protocols.

With Photons, power reduction is done by sleeping the device often coupled with timed or event-driven (external interrupt) wakes. With the Xenon, the firmware will eventually allow very low power operation with a much richer set of waking events allowing for very low power operation. One goal is to create a “sleep node” Xenon firmware that will not act as a repeater, only a node.


#8

It will be interesting to see the Photon vs. Argon power - both with WiFi but STM32F205 / BCM43362 vs. nRF52840 / ESP32-D0WD.


#9

@rickkas7 - to try and answer my original questions:

  1. Is a maximum current of 15mA on the xenon when transmitting? What would a duty level on that be? 10% so 1.5mA continuous or likely less than this.
  2. any idea when the low power modes will be implemented?

#10

I have no idea how accurate these numbers are, but I got them using this. I think they’re at least good for ballpark comparisons. (Testing was with 0.8.0-rc.25 firmware. I don’t expect rc.26 to be much different.)

Xenon:
Listening mode: 5.7 - 7.2mA
Connected to mesh 14.2 mA

Argon:
Listening: 8.2mA
Connected: 39mA

Boron LTE:
Listening: 8.2mA
Connected (Safe mode): 27mA
Connected: 26-104mA (?) (running BlinkAMeshDevice)


#11

Thanks Dave.

Sounds like I need to wait until power saving modes are implemented to be able to determine how low the xenon will go and whether a battery powered product could both function in a mesh network and run for a year between charges.


#12

Interesting I get different results all higher,
Argon in pairing mode(can’t test any other mode :frowning: sits at 65-69MA 8*more than you stated, is the esp32 switched off in listening mode?
It drops to under 4 if I hold down the reset and then if I also ground the EN to disable the regulator (powering through 3.3 pin) it drops to 1.1MA so deep sleep when it is possible will not be less than 1.1MA which will not be good enough for most battery scenarios ~30-40days off 2 AAs.
The onboard regulator is actually pretty good Datasheet Quiescent Current will be between 15-70ua which is not bad for a dev board I am used to the cheap chinese dev boards which drain 4-5MA in deep sleep…


#13

I just measured an Argon again using the same meter. (rc.26 prerelease)

Listening/Pairing ~8mA
Paired ~89mA (I didn’t test this before)
On Line (breathing cyan) ~38mA. About the same with 1 Xenon on the mesh

So that’s about the same as what I saw before.

Once we have a BLE API, it will be interesting to see if the power consumption is as high when actively doing BLE Stuff, as compared to when a mobile device is paired to the Argon.


#14

I just checked a Boron LTE with a µCurrent GOLD, Powered via 4.00V on Li-Po Connector.
Cloud Connected was 21 mA.
Grounding the EN pin obviously shutdown the Boron and dropped the current to 76 µA (0.076 mA).

Xenon was 29 µA, same setup (4.00V on Li-Po Connector, EN pin Grounded)


#15

Interesting, I was using 3.3v direct to 3.3 pin. uCurrent GOLD is a nicer device than mine so must be correct, I wonder how it was 3000-4000% out though. Looks like I will have to invest in a better peice if kit.
Can you please do some other measurements esp the Argon as it includes an ESP32 and is stating very low working consumption.

This is actually great news and means although not as good as a barebones these are viable with batteries for long periods of time using sleep.


#16

OK so when listening it must have the ESP off or sleeping.


#17

I have a uCurrent Gold as well; I need to test it against the meter I used for the numbers I posted. I’m afraid I might’ve blown it (the uCurrent Gold) up; this will be a good test. Alls I needs is the time to do it :roll_eyes:.


#18

I felt pretty comfortable with my measurements… considering I was close (76 µA) to the Boron Datasheet:
image

The difference is I applied power to the Li-Po Connector on the Boron.
There are 2 reasons for that:

  1. That’s how it will be powered in a battery application
  2. According to the Boron datasheet: 3V3 PIN: Unlike the Xenon or the Argon, this pin CANNOT be used to power the Boron.

#19

I did the same to my first uCurrent Gold :persevere:

It’s so easy to forget to change the current level when you start testing non Sleep modes. I’m on my 2nd unit now.


#20

Measured with µCurrent GOLD, 4.00V on Li-Po Connector, EN Pin pulled LOW:

Boron LTE  76 µA
Argon      31 µA
Xenon      29 µA

Measured with µCurrent GOLD, 3.34V on 3V3 Pin, EN Pin pulled LOW:

Argon      Wont Shut Down
Xenon      Wont Shut Down

Measured with µCurrent GOLD, 5.00V on USB Connector, EN Pin pulled LOW:

Boron LTE  1.3 mA
Argon      1.3 mA
Xenon      1.3 mA