[Ovmsdev] Introducing myself and questions on deep sleep

[Michael Balzer]

Patrick, Mark is probably right assuming you've been measuring with the 
modem still powered on; with the modem still enabled, I also see a 
minimum consumption level at around 250-280 mW.

The modem is on by default on the initial boot (first power up), that's 
due to hardware defaults. So on an initial power up, you always need to 
wait for the system to power the modem down before doing measurements. 
That will normally take about 80-90 seconds.

You can easily see if the modem is off by observing the blue LED. From 
the log you can normally tell it's off by seeing these messages:

I (80323) cellular: State: Enter PoweredOff state
D (80323) events: Signal(system.modem.poweredoff)

Another option is checking the "cellular status" command showing "State: 
PoweredOff".

You can also control modem power by the switch S1 on the modem board. 
You need to push it for 3 seconds to manually power off. Power on only 
needs about half a second. Be aware the driver will need some time and 
possibly some modem power cycles to resync if you change the power state 
manually when awake.

Regards,
Michael


Am 21.11.22 um 07:53 schrieb Mark Webb-Johnson:
> It should be the other way around (particular at low power sleep). The usb serial converter chip draws current but only from usb, so when powered via 12v that should be off and not consuming anything. Without a modem and in deep sleep that made a significant difference.
>
> I guess the difference you are seeing is most likely the modem. That consumes the most power, but in some cases can’t be powered by usb due to insufficient power availability (particularly over low powered usb ports on laptops, etc).
>
> With the modem powered on, there are significant differences in power consumption depending on whether it is locked onto a cell tower, or searching, and the frequency / technology negotiated. 4G is pretty power hungry.
>
> It is hard to get much benefit from deep sleep with the modem powered on. Some other systems get around this by putting the modem in sleep mode as well; awoken by a sms message.
>
> Regards, Mark
>
>> On 21 Nov 2022, at 2:01 PM, Patrick Stein <4seasons-ovms at jinx.de> wrote:
>>
>> Hello Michael,
>>
>>
>>> On 14. Nov 2022, at 17:26, Michael Balzer <dexter at expeedo.de> wrote:
>>>
>>> Am 14.11.22 um 10:25 schrieb Patrick Stein:
>>>>> As written in the issue discussion, there's a minimum load from the unswitchable components. In deep sleep mode, that's around 155 mW with the GPS antenna attached, and ~ 100 mW with GPS antenna detached. An option to control the GPS antenna could be using a simple 12V relay, either on SW_12V or on the ignition 12V line, to switch the antenna's GND connection.
>>>>>
>>>> I’ve never seen such a low value - lowest I’ve seen is 250 mW in deep sleep with all my four modules.
>>> I did the measurements using a USB power meter, just verified with a multimeter for 12V (11.6V Lipo), which gave slightly higher results:
>>>     • base load in Wifi mode, GPS antenna attached ~ 60 mA / 700 mW
>>>     • sleep, GPS antenna attached ~ 16 mA / 180 mW
>>>     • sleep, GPS antenna detached ~ 11 mA / 130 mW
>>>
>>> So nowhere near 250 mW. Mark, any idea about this?
>> I now know why you have different measurements. I bought a USB power meter and it just arrived and it’s now clear. I have just tried one module (v.3.3 with the current edge software) asleep at 9 Volts and it draws around 490 mW (54-55mA) , when I switch my lab power supply off it draws 290mW at 5.1Volts (55mA) over USB.
>>
>> So it seems that the module requires a lot less over USB than over OBD.
>>
>>

-- 
Michael Balzer * Helkenberger Weg 9 * D-58256 Ennepetal
Fon 02333 / 833 5735 * Handy 0176 / 206 989 26

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