Is the element missing on the board?..

[OrionK]

Hello everyone! Today was the first day I received my Crazyflie and already faced a problem
Device seem to work just fine except a very short range where it accepts a signal from crazy radio. I followed the FAQ instructions and did all the tests, replaced the antenna on the dongle. Same result. Well after playing a little I tend to think that the problem is on the board of the crazyflie itself. After checking the schematics I found out that I do not see L1 element. Please see a close-up picture of my board and tell me if I am right or wrong...
Schematics were taken from here: http://wiki.bitcraze.se/_media/projects ... _rev.f.pdf
page 3.

Thanks!

[marcus]

Hi,

That soldering looks pretty bad and the fact that one component is missing is very bad. Could you contact Seeedstudio technical support about a replacement unit? Include the link to the image in the message.

/Marcus

[Justin]

Hi RrionK,

This is Justin, the NPI engineer who in charge of this project. I am so sorry to hear about this. I think the unit you received should have been repaired manually and missed that component. Sincerely apologize for the inconvenience.

[OrionK]

Hello! Sorry for the late reply but I was traveling and did not have time to reply.
Does that mean that I purchased a refurbished item? Quite strange... I was thinking I am buying a new one...
I put the element on the board but it did not completely fix the problem. I am getting a maximum 6-7 meter range and then loss of connection. Any ideas?

[tobias]

Have you contacted Seeedstudio support? The should replace/fix your defect unit.

You should get at least around 20-30m if there are no other RF interference. You can try switching radio channel and/or datarate.

[OrionK]

Yes, I did contact them and they offered me to send the board back to them for repair or to send me the missing element. I was leaving the country at this moment for several months so it was not an option for me. I understand that it is my problem and you cannot do anything about it. I think in my situation the best I can do is to do a repair myself but I have to determine what is causing the problem. From what I've read so far there is a number of users that experience similar problems with reception. Some of them fix the problem by replacing the antenna element with a piece of wire of certain length. Some can't fix it at all.
Question is - why did I get the refurbished board when I paid for a new one. Seems like the board has been repaired and repair was not successful. And still it was sold as a new one. At least this is how it seems to me. Tell me if I am wrong.

[tobias]

If I understood you right you have already soldered the missing component, a 3.9nH 0402 inductor but the radio range is still bad? Replacing the the chip antenna with a wire might increase the range but doesn't fix the root cause so I don't see it as a real solution.

I agree, shipping a board like that is unacceptable. I think it is OK to do some manual patching of the board if it didn't pass the production tests but then it has to be well done, not like yours. Seeedstudio is responsible for the hardware and we will once again take it up with them. Well get back to you.

[Justin]

Sorry for bringing so many trouble to you. Our QA will contact you and deal with this problem.