4
\$\begingroup\$

As requested by Marcus, here is a short post about a piece of hardware I bought recently from Little Bird Electronics.

I recently bought an XBee Arduino Shield, and was a bit curious when I tried to use it the first time. When I connected it to my arduino, it seemed like it wasn't able to be pushed down enough onto the arduino, but now I'm starting to think that it's missing the black plastic bits on the pins on each side. This means that while the shield is connected to the arduino, if you press gently on either side of the shield on top of the either of the two rows of pins, you can actually rock the shield from side to side.

Here is a photo of it (sorry it's not a very good photo):

alt text

\$\endgroup\$
4
\$\begingroup\$

That's what it looks like to me as well. However, this might be a new design - Compare carefully to this picture, and you'll see that those headers are offset (and therefore have black plastic bits on the male headers), while yours appears to use stackable headers, which never have black plastic bits on the pins, because then you couldn't put them through the holes!

Try moving it just a little to the side, so the shield PCB rests on the female headers (as if you could push it all the way down).

If you've got less than the pitch of the connectors between the bottom of the male pins and the Arduino PCB (or the male pins are touching the PCB) then the pins are too long, your female headers are too short, or you need the black plastic bits for spacers. In this case, I'd probably just cut 4 pins off of a male header strip, pull the black plastic bits off, and then push them onto the corner pins on your XBee. You could also carefully trim the pins to be a little shorter, or you could get back in touch with Marcus for a replacement which matches the picture.

If you've still got 0.1" between the bottoms of the pins on the XBee and your Arduino PCB, then you're either not pushing hard enough or you've got a piece of something (probably a broken wire) stuck in the bottom of one of your female headers. In this case, you need to replace the plugged header on your Arduino.

Does this answer your question?

\$\endgroup\$
4
  • \$\begingroup\$ Hi, Thanks for your reply. Thanks for pointing out the different types of headers, I didn't even notice it. I can't push the shield pcb all the way down on one side of the arduino - it moves a bit, but not enough to go all the way down. It seems that if the shield pins did have the black plastic bits, then it would sit perfectly (the gap looks to be almost exactly the right size for them). \$\endgroup\$ – user1049 Aug 12 '10 at 6:50
  • \$\begingroup\$ I've tried pressing the shield on with a reasonable amount of pressure, but the icsp connection is not letting it go down any further (even if the icsp header did push all the way down, I think there might still be at least some sort of gap between the shield pins and the arduino). \$\endgroup\$ – user1049 Aug 12 '10 at 6:50
  • \$\begingroup\$ I've also tested my arduino with other shields (I don't have any with the stackable headers though), and they seem to work fine. I was offered a replacement by Maddy which I accepted, and in the meantime asked Marcus about the possibility of refunding it for store credit, which he accepted. The replacement must have already been posted though, because that arrived today. I had a look at the replacement they sent me, and it seems to be exactly the same with the stackable headers, so this one also has the gap between the shield and the arduino. \$\endgroup\$ – user1049 Aug 12 '10 at 6:50
  • \$\begingroup\$ unknown - Looks like a new ICSP header is in order! Those female sockets are available in different heights and contact depths. For instance the Digikey part S7106-ND is 8.5mm tall, and has a contact depth of 6.38mm, while the A32934-ND is shorter at 8.13mm tall, but only has a contact depth of 3.77mm (take a look at the datasheet images and you'll see what's going on). See also the 609-3582-ND and 609-2267-ND. So, your options now are to trim the male pins on your ICSP header, or to get a female socket with deeper contacts. \$\endgroup\$ – Kevin Vermeer Aug 12 '10 at 13:20
2
\$\begingroup\$

It might be the plastic bits, but I am not convinced yet. A number of Long pin female connectors don't have these. So long as there is electrical conductivity, you should be fine.

Rocking from side to side suggests that the shield is touching something on the Arduino and it's acting as a fulcrum. Check that, as it could cause electrical problems. Also, can you post an oblique view?

\$\endgroup\$
2
  • \$\begingroup\$ Looks like it might be the ICSP pins bottoming out that are causing the rocking. \$\endgroup\$ – pingswept Aug 11 '10 at 15:22
  • \$\begingroup\$ Yes that's what seems to be happening - I've tested with another shield that has an icsp header on it (although it has the regular pins on either side of the shield, not the stackable headers), and the icsp header on that appears to be able to be pushed down further than the one on the xbee shield. \$\endgroup\$ – user1049 Aug 12 '10 at 6:55

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.