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Topic: RFM12B and vRestrict (Read 371 times) previous topic - next topic

MobileWill

Hi, I am designing a small Arduino based micro with the RFM12B radio. The eagle footprints I find all have a vRestrict area underneath a good portion of the radio. Can I remove that or is that really needed? I really need the space for routing since I am trying to fit everything in a 30x30mm square.

The only way I was able to get the footprint was from opening another design that had it. Which most came from Jeenode.

Thanks.
-William
Current Projects:                    Arduinos:
Security Robot Tank               Uno
Security Robot II 4WD            Mega2560

http://mobilewill.blogspot.com

MarkT

It'll be there for two reasons probably:

1) To keep RF signals from coupling to your board - actually this should only matter near the antenna pin.

2) to prevent the traces on the bottom of the RFM12B module from shorting (or running too close to) the
  traces on the PCB - there is no gap between the boards when its surface mounted so capacitive coupling
  could be an issue.
[ I won't respond to messages, use the forum please ]

MobileWill

Thanks, makes sense. Hmm, I am going to try hand routing but I think I am asking too much for such a small space. I have a Atmega328p, FTDI connection SMD, MCP1702 SOT89 regulator and 0805 caps, some headers with ICSP, with the RFM12B on the back.

Current Projects:                    Arduinos:
Security Robot Tank               Uno
Security Robot II 4WD            Mega2560

http://mobilewill.blogspot.com

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