BR-SC11A Antenna Problem??

Hello All,

I’m working with BR-SC11A BlueStamp and I’m having what appears to be a antenna problem. When first putting the BlueStamp on a breadboard and powering up, the BlueStamp could not be discovered by my laptop or PDA.

I checked all the bread board wiring (just 3.3V power) and everything looks correct. I thought perhaps the breadboard was not getting a good connection and decided to push on the device to make sure it was seated. What was strange is my laptop was still searching for local devices and it found the BlueStamp.

So thinking I had a bad breadboard, I replace it and tried everything again on a new breadboard. Same thing happen. So I did a little testing with just barely touching the BlueStamp and everytime my laptop would not discover the BlueStamp until I touched the BlueStamp. I did this several times with my laptop and PDA and would never connect until I touched the BlueStamp and then the laptop and PDA would find the BlueStamp everytime.

So my question is with the onboard antenna what is a typical range of the BlueStamp.

Could the antenna be bad?

John

we were having the same problem with the chip working on our senior project. What we ‘believe’ is that you have too much EMI around the chip. What info I have recieved from BlueRadios (inside source) is that you need a “ground plane” to cancel out the EMI.

DIFFERENCE:

We have 2 chips talking to each other. We are not communicating one chp to the computer. We applied this method to the Master chip.

We did most of our testing at the school lab, where there was a lot of EMI. Let me know if this is the problem, as I am putting it in my report.

http://www.sparkfun.com/cgi-bin/phpbb/v … php?t=1393

We saw a similar problem with the DIP test bed and a bread board. We were playing with a DIP module that tested fine in the test bed, but when put the DIP module in a bread board, it wouldn’t discover, or discover once out of 5 tries, etc.

The DIP modules are tested on a ‘test bed’ PCB with a low-cost LM317 with 0.1uF and a 10uF within 0.25" of the DIP module. The test bed has a substantial ground plane.

So the bread board can be difficult to get working. Be sure you have plenty of decoupling caps and a good voltage regulator.

-Nathan