Weak network on GoPiGo power


#1

Hi,

Just got a GoPiGo that I’m running on a Pi B+ with camera. I downloaded the Dexter Raspbian wheezy image.
I have two different USB WiFi dongles:
Sabrent USB-A11N and USB Wifi that came with Kano kit (Element 14 WiPi, I believe)

I made the experience with both dongles in the past (without GoPiGo) that they need perfect power input to provide a stable network connection without lost packets and fast ping times, only dedicated full-powered USB power adapters or USB batteries would do.

I’m seeing the same behavior on the GoPiGo with battery power where I get inconsistent ping times like:
Request timed out.
Request timed out.
Reply from 10.1.1.139: bytes=32 time=47ms TTL=64
Reply from 10.1.1.139: bytes=32 time=6ms TTL=64
Reply from 10.1.1.139: bytes=32 time=33ms TTL=64
Reply from 10.1.1.139: bytes=32 time=780ms TTL=64
Reply from 10.1.1.139: bytes=32 time=585ms TTL=64
Request timed out.
Request timed out.
Reply from 10.1.1.139: bytes=32 time=42ms TTL=64
Reply from 10.1.1.139: bytes=32 time=35ms TTL=64
Reply from 10.1.1.139: bytes=32 time=1ms TTL=64
Reply from 10.1.1.139: bytes=32 time=1ms TTL=64
Request timed out.

I tried to power the GoPiGo from both the battery pack plus a reliable USB power connection into the Pi board, but it seems that it’s the same behavior as if the USB power is disconnected. If I disconnect the Pi board from the GoPiGo board and just power it from USB, I get a constant 1-2ms ping, no lost packets.

I saw the issue with fresh batteries, right now after a while of trying the battery pack still outputs 11.5V, but I’m seeing above ping results.

I’d really like to use the python browser control, but it is not effective with the network behavior.

What is your experience with power and network behavior on your GoPiGo, is there another power supply or wifi adapter you would recommend?

Thanks,
Alex


#2

Hey Alex,

Hmm, this is a tough one. We certainly see slow ping times, but I’m not sure why things are getting dropped like you show it. Could there be an issue with your home network?

To answer your question, we use Monoprice wifi dongles. I’m not sure that they perform any better than the ones you listed, but they seem to be pretty effective.

What’s strange is that you still see degraded peformance with the Raspberry Pi plugged in via USB. Not sure what’s going on here.

John


#3

Hey Alex,

Hmm, this is a tough one. We certainly see slow ping times, but I’m not sure why things are getting dropped like you show it. Could there be an issue with your home network?

To answer your question, we use Monoprice wifi dongles. I’m not sure that they perform any better than the ones you listed, but they seem to be pretty effective.

What’s strange is that you still see degraded peformance with the Raspberry Pi plugged in via USB. Not sure what’s going on here.

John


#4

Hey Alex,

Hmm, this is a tough one. We certainly see slow ping times, but I’m not sure why things are getting dropped like you show it. Could there be an issue with your home network?

To answer your question, we use Monoprice wifi dongles. I’m not sure that they perform any better than the ones you listed, but they seem to be pretty effective.

What’s strange is that you still see degraded peformance with the Raspberry Pi plugged in via USB. Not sure what’s going on here.

John


#5

Thanks for your response. My Wifi network should be fine, as the same Pi board with same Wifi dongle at the same location in the house works flawlessly when powered on USB and not connected to GoPiGo.

I’ve seen this behavior before when the Pi board was connected to an underpowered USB power sypply.

In both cases (GoPiGo batteries and underpowered USB) there was a pattern that on an idle machine ping times would be ok, but when I started heavy processes such as camera capture, the ping response would deteriorate, probably due to extra power consumption from camera and busy CPU.

Regards,
Alex


#6

Hey Alex,
I think you are right about the problem being with the power supply. I have seen the Pi behaving very weirdly when it is not able to get enough juice from the power supply. One of the first things to take the hit is the Wifi. The connection keeps dropping or there is just poor performance. It would be great if you could get a 5V 2A power supply ot just use good batteries.

-Karan