Tip / Sign in to post questions, reply, level up, and achieve exciting badges. Know more

Smart Bluetooth

Anonymous
Not applicable

I'm trying to use P38 on the BCM20736S module and it's not working.  I have a custom board with the 736S module and a TAG development board with a 737 chip.  My code for putting output on P38 works on the TAG board but not on my custom board.  I have done this experiment using P38 as a SPI MOSI and as a GPIO output.  Both work on the TAG but neither work on my 736S board.  I know P38 is paired/bonded with P14 and I have disabled P14.   On the other hand P04 works both as MOSI and GPIO Output on my 736S module.  My SPI code works on the TAG board and it is based on the sample code in the documentation.  I have looked for conflicts and don't see any, pUART or otherwise.  My code is based on the Heart Rate Monitor App.

Is there something I should know about P38 that is not in the documentation?  I could switch to P04 but that means the entire design goes back to the drawing board and a new layout and PCB version, so I would like to use P38 for MOSI if possible.

p.s. I do see SCLK coming out on P24 when I transmit data via SPIFFY2 Master... but nothing comes out on P38 which is configured as MOSI.  Again, the exact same code works fine on the TAG board where I see both SCLK and MOSI on the scope.

Thanks for any suggestions.

Eric

0 Likes
1 Solution
MiTo_1583836
Level 5
50 likes received 25 likes received 10 likes received
Level 5

This issue has been solved, we have been able to demonstrate that a SPI communication is possible with the following SPI GPIO configuration: MASTER2_P24_CLK_P38_MOSI_P25_MISO.

View solution in original post

4 Replies
MiTo_1583836
Level 5
50 likes received 25 likes received 10 likes received
Level 5

Hi Eric,

I am reviewing the details of your post and let you know asap

MiTo_1583836
Level 5
50 likes received 25 likes received 10 likes received
Level 5

This issue has been solved, we have been able to demonstrate that a SPI communication is possible with the following SPI GPIO configuration: MASTER2_P24_CLK_P38_MOSI_P25_MISO.

MichaelF_56
Moderator
Moderator 250 sign-ins 25 comments on blog 10 comments on blog
Moderator

Thanks for the update 79rpm

I brought this up with the developers today and they said that if this works on the TAG board, then it should work on their SIP module design as well.

Anonymous
Not applicable

To clarify, there was no special trick needed to get GP38 to function as MOSI.  The problem was in our custom board.  There was a mis-wired MOSI connection which interfered with the GP38 output (both MOSI and GPIO).  When the bad connection was removed, the GP38  signal was observed to be present on the scope.

Eric