• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Subscribers 16 subscribers
  • Views 572 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

CC1101 SPI interface to MSP430F5438

Shanguo Lu
Intellectual 570 points
Other Parts Discussed in Thread: CC1101, MSP430F5438A

Hi,

We have interfaced the CC1101 radio to MSP430F5438A.

The signals on the CSn, SCLK, and SI pins looks normal. However, the SO (output pin of the CC1101) is always ground.

Reference design CC1101EM868-915MHz Reference Design 3.0 (Rev. B)  is followed, and there is no difference between our design and this reference design.

It is also found that the DCOUPL level is at 1.3V only (differs from the requirement of 1.6~2V). Also, 3V supply for both MSP430 and CC1101.

Could anyone help me on this? Appreciate your help.

 

Shanguo

 

  • 0
    TI__Genius 14940 points

    Sounds more like there's a short circuit somewhere on your board.  Possibly under the CC1101 device between on of the pin pads and the ground pad under the part.  Can you try depopping the part and then reassemble it.

    Jim Noxon

  • 0 in reply to Jim Noxon
    Intellectual 570 points

    Thanks. We had found some issues with our design. A replacement part for Johnson technology Balun is used in our design, does not function properly. This causes the RF-output pins short-circuited.

    We leave the RF output pins unconnected, but still not able to get the SO signal right.

    Additional info.

    - 3V supply.

    - SCLK, SI, DCOUPL, OSC, signals all looks perfect.

    I did not solder back the IC pad to ground during the re-work. Could this be the root of problem? I am trying to reassemble again with pad connected to ground.

    I have connected the MSP SPI to eval module, and it works.

    There are not many wires for the CC1101 to work, but it seems difficult to get it work.

     

  • 0 in reply to Shanguo Lu
    TI__Genius 14940 points

    The ground pad under the part must be soldered to the ground pad.  It is the only ground connection on the part and if it is not connected, the part will not work properly.

    Jim Noxon