sd_ble_gatts_hvx() and extra data

[Charles Horkin]

Hello,

I'm using Win 8.1 BT LE stack to communicate with the NORDIC. I am using soft device s110. I use notifications to send data to windows which assembles a message based on it. I am seeing that every so often (and it is not every time), data gets sent over BT that is extra data.

For example, I am meaning to send a 60 bytes of data and instead, windows receives an extra 27 bytes (87) of data. This is not the exact situation, but is pretty close. Also, these 27 bytes seem to be random. The bytes also seem to come in the middle of the stream, so I get something like 40 good bytes, 27 garbage bytes, then the remaining 20 good bytes.

I'm 90% sure it's not my code because the code is just reading from the SPI bus and then sending the data. I've verified the SPI bus data with the logic analyzer is correct (60 bytes) and that the data Windows gets is the 87 bytes as described before.

Is this a know issue? Is there a workaround? Am I missing something?

Thanks.

[Charles Horkin]

I looked at the data going into that function and it appears to be the same as on the SPI bus. I'm wondering if windows might be doing something strange with the data, but I can't prove one way or another that it's Windows and not the NORDIC chip.

I don't think the packet sniffer will work if I'm already connected to the BT with Windows BT driver, right?