Which system do you use? Android, Ubuntu, OOWOW or others?
Ubuntu from OOWOW
Which version of system do you use? Please provide the version of the system here:
Ubuntu-gnome- 24.04 5.15
Please describe your issue below:
Basically, I am getting different performance for data transmission when the VIM4 is plugged-in vs battery powered. What I did is run the Quectel Manager → Start openvpn → gst pipeline for SRT streaming", everything works as per normal when it is plugged in. However, when it is powered by battery, data transmission is significantly slower. When plugged in, I can ping the streaming server with roughly around 30ms to 70ms during streaming, but on battery powered, the ping goes up to 2000ms - 10000ms.
I tried the following to maximize the performance on battery powered:
adjusting the scaling_governor to performance using (“echo performance | sudo tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor”)
adjusting the min frequency to match the max frequency (“cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_max_freq | sudo tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_min_freq”
What else am I missing? Can somebody help me with this?
I don’t have that modem so this is just conjecture. The charger you posted is just for charging batteries, not running a multicore device. Big difference, also keep in mind those selling stuff like that lie, big lies, why. Overwhelming majority of the users don’t even know what mAh is, so they get away with lies.
Cut off the end of the usb cable and make sure one of the wires is large diameter that can actually handle current. Buy a big 5 Volt battery and connect to it, one that will be stiff and can handle the peak current impulse. I suspect the modem is shutting down and rebooting due to low voltage conditions, guess, not for fact.
One of the vim4 boards was at a remote site for over 2 years on battery and solar power. It ran without any problems until recently.
Thank you for your insight on this. I am not very experience with batteries, but I am looking for a small form factor powerbank because I need the VIM4 to be portable, small enough to put in the pocket etc. I forgot to mention that when I plugged in, I plugged it into the portable powerbank connected to the VIM 4, so there’s some sort of pass through I think. Does it justify that is a legit powerbank?
Also, it seems to drain quite fast, so I might need to look for a new solution to this. Would appreciate if you have any suggestions on this.
That powerbank you linked does not say USBC PD - Our experience is that you need PD for reliable use of a 5G module (in our case an RM520) . It doesn’t seem to matter how high current your 5v supply is, you’ll start to see TX problems when the modem is at the edge of coverage, in extreme cases the whole board will reboot.
Get a decent USBC PD power bank and it works for hours on end. (or supply 12v to VIN).
Thank you so much for the help. May I know if the voltage matters as well? Previously I searched based on the recommended voltage 12V, hence I selected that powerbank since it supports 12V with 30W. So I was wondering if the W matters since it allows supports for higher V If I my understanding is correct.
I don’t know the theory here.
All I can tell you is that empirically if I put a VIM4+Camera+5G modem on a normal USBC power pack it will misbehave. If we use a USBC PD power pack it works reliably. It also works reliably if we wire VIN to the car’s (nominal) 12v wiring loom.
You can get away with a 5v USBC pack if you are using 5G SA and the cell is close and you have decent antenna - but it is best not to plan for that.
Hi all, thank you guys for your insights on the matter.
So apparently, on the box of that powerbank, it does says PD and yesterday when I tested it again, it worked.
I absolutely have no idea why it failed that time. Anyone know what else could have happened? Maybe my antena did not attach properly or something?
Also, on the Aukey powerbank it displays the output wattage as 7.3-9.1W when I was streaming my UVC to a streaming server. Hopefully this is of help to anyone who requires the info. Does this mean that the device is only taking 5V/1.46A while streaming?
We find that power usage on 5g is very sensitive to the quality of the TX antenna and the distance to the tower - I tried putting 60dbm of attenuator on the antenna and the power consumption jumped to ~12w. Also it is higher in the rain (frequency dependent). Yes 7->10w is about right for normal use - but I don’t think that is at 5v I think the VIM4 negotiates 9v or more.
One more thing to watch out for: Quectel 5g modems overheat really easily, You’ll need a heatsink and probably a fan. When the modem is hot it can shut down for a few seconds to cool off, which may be what you were seeing.