BC127 - BLE Notifications throughput

We are using a custom BLE profile on BC127 evaluation kit, configured at 9600 baudrate.

BC127 is configured as a peripheral device to connect with an Android app (central).

At the moment, we are sending 20 bytes of notification data using command “BLE_NOTIFICATION…”. We have noticed that when we send this command, BC127 takes about 20-30ms to respond with “PENDING” before we can send the actual payload.
This means that the fastest rate at which we can send notifications and receive at the other end is every 30-40ms (25-33Hz rate equivalent to 500-660Bytes/Second).

We need to be sending this data at 250Hz (5KB/s), how can this be achieveable with BC127? The connection interval is 7.5ms and we have tried with increased uart baudrate of 115200bps but the outcome is the same.


Could anyone help with this please?
We have tried baudrate of 460800bps but BC127 doesn’t seem to be able to accept data any faster than 20-30ms using BLE_NOTIFICATION command. This has become a blocker for the project.

BC127 seemed to be a very promising module for our applicaiton but it’s such a shame that due to lack of support we have decided to give up on this module.


The throughput BLE depends on Maximum transmission unit (MTU)
According to Melody Audio 7.x User Guide r3.pdf : In Data mode, max throughput is approximately 100 kbps server-to-client, and up to 8 kbps client-to-server (with MTU=120).
You can try configuring the MTU BLE parameter with BLE_CONFIG command


Hi Donald,
We have tried with maximum MTU size of 158 as well. We are not using BLE in Data mode, instead sending Notifications as a custom profile. BC127 does not seem to accept any faster than 30ms per notification data send request from the host (command “BLE_NOTIFICATION…”), nor does it seem to be sending multiple packets per connection interval.
We are able to achieve over 5KB/s data rate through TI’s CC2541 chipset using the exact same profile and even with MTU size of MTU (which is a bit outdated chipset). WIth that we can see that CC2541 is able to buffer notification requests very quickly and can send multiple notifications per connection interval.
Is that all possible with BC127?

Hi s.ali,

Yes, it is.