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Re: Too many packets lost error

Posted: Sun Jul 14, 2013 9:00 am
by fsedano
Hi,

Just received the quad and started playing with it, hoping to do some development. But I'm facing some issue with the crazy radio. The effective distance I'm getting is around 1 meter. If the quad is farther than this, I'll lose connectivity, usually requiring quad reboot to get link again (scan does not find it).When about 1meter distance, the link strength bar moves very quickly from 100% to 0% (like several times per second).

I tried without the antenna and i can't get a connection at all, even very very near the quad, so I guess the antenna is at least working.

Tried 1M and 250K, and several channels with no luck ... I'm running out of ideas! I had very little luck having the PS3 controller recognized on Parallels, so I'm using a Win7 laptop.

Thanks,
Francisco.

Re: Too many packets lost error

Posted: Sun Jul 14, 2013 10:14 am
by atomicdog
fsedano wrote: I tried without the antenna and i can't get a connection at all, even very very near the quad, so I guess the antenna is at least working.
The antenna could still be damaged and not working at 100% even if it helps a little.

You should also check the antenna chip on the CF to make sure it's not cracked and broken.

Re: Too many packets lost error

Posted: Sun Jul 14, 2013 11:15 am
by fsedano
Thanks, it does make sense I'll try. What surprises me is link quality jumps from 100% to 0% several times per second. Is that usual?

Re: Too many packets lost error

Posted: Sun Jul 14, 2013 2:06 pm
by fsedano
By the way, where are the schematics and layout for the CF? I can't find them on the repositories, wanted to check for cracked things.

Re: Too many packets lost error

Posted: Sun Jul 14, 2013 8:27 pm
by atomicdog
Thanks, it does make sense I'll try. What surprises me is link quality jumps from 100% to 0% several times per second. Is that usual?
I don't remember ever seeing something like that happen. Have you tried changing the radio channel or going some where that wouldn't have a lot of interference?
fsedano wrote:By the way, where are the schematics and layout for the CF? I can't find them on the repositories, wanted to check for cracked things.
Their at the wiki site.

Re: Too many packets lost error

Posted: Mon Jul 15, 2013 11:23 am
by marcus
fsedano wrote:Thanks, it does make sense I'll try. What surprises me is link quality jumps from 100% to 0% several times per second. Is that usual?
The filtering of the signal strength isn't very good (there's a bug reported for it) so if it's jumping like that it's normal. But it's not normal that you only get 1m of distance... Do you have another antenna that you could try? Just a normal one of a WiFi router will do.
fsedano wrote:By the way, where are the schematics and layout for the CF? I can't find them on the repositories, wanted to check for cracked things.
The schematics and component placement are on the wiki. What you should be looking for for the component Y1 (at the bottom left) in the top placement drawing. It's a blue component that's roughly 1 cm long and says "AF ->" on it.

Re: Too many packets lost error

Posted: Mon Jul 29, 2013 5:32 pm
by cvh
Hi there,

I have exactly the same problem. I got the crazyflie 23 juli, the day after I soldered the motors on it. Since the 24th I'm trying to make the crazyflie fly further than 1m away from the antenna, but no success. Sometimes it even disconnects just when I start spinning the motors.

At first I thought it must have been a problem I created, so I inspected the board very well, but couldn't find any visual defect. Furthermore this wasn't the first time I soldered small contacts, I have some degree of experience in soldering.

I tried many things, in the hope of finding the problem and posting it here, but I didn't. I tried changing the antenna, in fact I tried 3 different antenna's I am using in my wifi setup, so those are sertanly working. But no better results. When setting up the bitrate at 1M or 2M, I never can connect, I can only connect at 250k. I used wifi scanners to try and set a frequency that isn't used in my area. As I understand the documentation on the chipset, you should make the sum of the number (=channel) you entered and 2400 to get the running frequency. But that didn't seem to make it better, in fact results were worse.

The only I didn't test yet, is running the software on a native linux machine. I am a linux professional who migrated everything to centos last year. Since centos6.4 does not support python2.7 for now, I didn't want to spend the time compiling everything and had a go on a windows xp installation. After that I tried the VM provided, which worked a little better but only because of the reconnect radio switch. I even tried under windows 7 to see if I had different results(NOT!). :(
I'll setup an ubuntu machine when I have some time, and post the results here. But it doesn't look good.

Are there any more checks I can do? Is the problem situated on the crazyradio, or is it possible that the problem is situated on the crazyflie? Can I test something to prove this?

Re: Too many packets lost error

Posted: Mon Jul 29, 2013 7:11 pm
by tobias
It really sounds like a a broken RF component. We have experienced the same behaviour when there was a crack in the soldering of the chip antenna on one of our Crazyflies. Resoldering fixed that. Try inspecting the RF components and see if you can find anything. It's the small 0402 inductors and capacitors between the blue chip antenna and the QFN chip.

Re: Too many packets lost error

Posted: Tue Jul 30, 2013 1:12 pm
by cvh
Ok, so you think the problem is situated on crazyflie. So I can stop testing the crazyradio..
I'll try and find the problem this evening!

Thank you for replying this quickly! ;)

Re: Too many packets lost error

Posted: Wed Jul 31, 2013 7:57 am
by fsedano
Hi,

I'm on the same boat. I tried with a friend's crazyflie and crazy radio and it's my crazyflie what is broken. So, I did the following troubleshooting:

- Check crazyflie board for cracks under microscope
- Swap ceramic antenna on the board
- test for continuity on the PCB

Everything looks good, but I'm still getting like 1meter range. If I remove the ceramic antenna then range is 0, so it seems it's doing at least something..

I'm at a loss, any hints?

Thanks,