2 Servers 1 client data synchronization (nrf52832)

[stackGreen]

Hello,

I’m using two nrf52832 as servers sending 20 Byte data with 18 ms notification interval.

Notification Data:

[incremented uint8_t ] [19 byte data]

Client:

I recognized, that the softdevice is processing multiple Datapackages from one Server.

<info> app: From: 1, Data: 11

<info> app: From: 1, Data: 12

<info> app: From: 0, Data: 250

<info> app: From: 0, Data: 251

<info> app: From: 0, Data: 252

<info> app: From: 0, Data: 253

<info> app: From: 0, Data: 254

<info> app: From: 0, Data: 255

<info> app: From: 0, Data: 0

<info> app: From: 1, Data: 13

<info> app: From: 1, Data: 14

<info> app: From: 1, Data: 15

<info> app: From: 0, Data: 1

 

I want to synchronize the received data on my nrf52832 client so I created a “receive buffer”.

The Receive Buffers:

Receive Buffer  Notif. Data[0]       Notif. Data[1]   Notif. Data[2]   Notif. Data[n]

Buffer Server1 [20 Byte]                             []                             []                             []

Buffer Server2 [20 Byte]                     [20 Byte]           [20 Byte]              [20 Byte]

If column Data[0] is full the data will be printed with uart. And column Data[1] will be Data[0], waiting for new Server data …

With this buffer I achieved to synchronize my received data ( Checked with the incremented uint8_t data).

Problem:

Although the servers are sending data with identical parameters, one “receive buffer” always fills up. With 20 Byte data and 18 ms notification interval around 2 Datapackages in 10s.

Does anybody know how to handle and synchronize data from multiple servers?

 

Thanks and Greetings

[Sigurd]

Hi,

How about increasing the buffer size? Or depending on throughput requirements, use indication instead, so that you need to do application layer ack before you receive the next package.

[stackGreen]

Increasing the buffer is only delaying the overfill of one buffer. Using indication could be one solution, but will decrease my datarate ... I will give it a try.

Thank you so far.

[Sigurd]

stackGreen said:

Increasing the buffer is only delaying the overfill of one buffer.

So one device is always sending more data than the other device.

stackGreen said:

Using indication could be one solution, but will decrease my datarate

If the decrease in datarate is not acceptable, you could implement your own logic where you turn off the notification when your sync-buffer is full.