Sending more than 8bits of data over bluetooth

[Alex Lynchosky]

I'm looking into the service creation portion of BLE, and I've made it pretty far. But one problem that I'm running into is sending more than 8 bits of data at a time back to the board. The service example provided, Immediate Alert Service (IAS), can only send 8 bits at a time. I've dug fairly deep into how they send data, and I hit that 8 bit wall every time. Is this a restriction to all services or only the examples?

So in short, is there an easy way to send more data that I am missing?

Thanks in advance!

[Carles]

Hi Alex,

First of all, I would like to point out that all headers included in the SoftDevice package, and more specifically those prefixed by ble_, are system headers and should not be modified at all.

The "data" member of the ble_gatts_evt_write_t is meant as a placeholder for the address in memory where the array containing the data received over the air lives.

This means that, without modifying the header file, you can simply get the data by accessing:

ble_gatts_evt_write_t::data[0 .. len-1]

So assuming that ble_gatts_evt_write_t::len was 10, you could access:

ble_gatts_evt_write_t::data[0] .. ble_gatts_evt_write_t::data[9]

Hope that helps,

Carles

[Mohamed O.Abouzeid]

I have two somethings that confused me: what will happen if I didn't send packets for a while and the chip didn't sleep then I send again packets will it write starting from data[0] or will complete on the array?

the same case but the chip in this case go to sleep and then I started to send again.

[Mohamed O.Abouzeid]

I'm also asking about how to make the chip to erase the array of the data received from air every time it start receiving packets from air?

[Carles]

Hi mohamed,

Please start a new thread with this question, since this does not seem to be related to the issue covered in this thread.