CC2541: LL_STATUS_ERROR_CONN_FAILED_TO_BE_ESTABLISHED when trying to connect to peripheral device

Athul P Satheesan

Part Number: CC2541

Hi,

i am using simpleblecentral device and Keyfobdemo for my central and peripheral. sometimes when i try to connect the devices, i get LL_STATUS_ERROR_CONN_FAILED_TO_BE_ESTABLISHED. but it connects when retrying. it is happening asynchronously. what are the reasons for LL_STATUS_ERROR_CONN_FAILED_TO_BE_ESTABLISHED?

over 7 years ago

0 Marie H over 7 years ago

TI__Guru* 83691 points

Hi Athul,

LL_STATUS_ERROR_CONN_FAILED_TO_BE_ESTABLISHED normally means that the timing is off (so the device misses the connection event).

Can you double-check your hardware, especially that everything is good with the crystal? (See for example this thread, where the poster war using the wrong capacitance on the crystal: e2e.ti.com/.../295940 )

You should also check that you're not doing any time-consuming function calls in the callback functions (see this thread where the poster has printf calls that delay the BLE stack: e2e.ti.com/.../420925 )

0 Athul P Satheesan over 7 years ago in reply to Marie H

Intellectual 710 points

Hi Marie,

Thanks for the reply. But the problem happens randomly. sometimes it connects with the peripheral immediatly, some times after 2 or 3 retry.
I have added some code inside GAP_DEVICE_INFO_EVENT for connecting to a peripheral with desired device name. will that be an issue? But i receives GAP_LINK_ESTABLISHED_EVENT.

0 Marie H over 7 years ago in reply to Athul P Satheesan

TI__Guru* 83691 points

Hi Athul,

GAP_DEVICE_INFO_EVENT happens every time the scanner discovers a device, i.e. when the central device is scanning. You should wait until the device is finished scanning (or terminate scanning) before attempting to connect with devices. E.g. Use the GAP_DEVICE_DISCOVERY_EVENT, which means that the central device is finished scanning.

0 Athul P Satheesan over 7 years ago in reply to Marie H

Intellectual 710 points

Hi Marie,
Thanks for your reply. I uses GAPCentralRole_CancelDiscovery() for cancel scanning, when the particular device is found

0 Marie H over 7 years ago in reply to Athul P Satheesan

TI__Guru* 83691 points

Hi Athul,

I would still advice you to wait for the GAP_DEVICE_DISCOVERY_EVENT (that will be returned when you have called GAPCentralRole_CancelDiscovery().)

How often are you getting LL_STATUS_ERROR_CONN_FAILED_TO_BE_ESTABLISHED? Are you working in a noisy environment?

0 Marie H over 7 years ago in reply to Marie H

TI__Guru* 83691 points

Hi Athul,

Did you solve the problem?

I will close this thread due to inactivity.

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CC2541: LL_STATUS_ERROR_CONN_FAILED_TO_BE_ESTABLISHED when trying to connect to peripheral device