Android GATT 133 error

RE: Android GATT 133 error

victor passe — Tue, 29 Sep 2020 13:46:07 GMT

Can this fix be applied on S110 V8.0 also?

RE: Android GATT 133 error

Mttrinh — Fri, 27 Jul 2018 13:01:33 GMT

No, not that i'm aware of at least.

RE: Android GATT 133 error

howard n2wx — Tue, 24 Jul 2018 15:10:01 GMT

The question came up as part of a hunt for a workaround when using a Moto Android. Has the root cause of the Moto and Error 133 GATT been identified?

RE: Android GATT 133 error

Mttrinh — Tue, 24 Jul 2018 14:12:12 GMT

Hi,

This compatibility mode was removed for the s132 5.0.0 when we added support for overlapping procedures. So this should be enabled by default in the SoftDevice. For most LL control procedures, if the peer has initiated a procedure and then initiates one of the simple procedures (either version ind, feature req or LE ping) the SoftDevice handles the overlapping procedures.

RE: Android GATT 133 error

howard n2wx — Wed, 18 Jul 2018 20:59:30 GMT

Hello Mttrinh,

Compat mode 2 doesn't seem to be present in s132 6.0. Is there another way to invoke it in 6.0?

Thanks, Howard

RE: Android GATT 133 error

Mttrinh — Fri, 13 Apr 2018 08:48:25 GMT

Hi,

This is a known issue with Android, we have had similiar issues where error 133 is returned. In those case we had sniffer traces, and saw that the phone first sent a LL_VERSION_IND and then it sent a LL_FEATURE_REQ before the peripheral had sent its LL_VERSION_IND. In other words, the phone initiated a seconds LL Control Procedure before the first is finished, and this is a clear violation of the Bluetooth specification. The SoftDevice will disconnect at this point.

The Bluetooth Specification Version 4.2 [Vol 6, Part B] Chapter 5 (page 2634), the second paragraph states the following:

"...For all other Link Layer Control Procedures, only one Link Layer Control Procedure shall be initiated in the Link Layer at a time per connection per device. A new Link Layer Control Procedure can be initiated only after a previous Link Layer Control Procedure has completed. ..."

Can you try the sniffer and see if this is the case for you too?

To solve this issue we added Compatibility mode 2 to the softdevice.

So If your case turns out to be the same you can enable Compatibility Mode 2 by adding this:

ble_opt_t ble_opt;

memset(&ble_opt, 0, sizeof(ble_opt));

ble_opt.gap_opt.compat_mode_2.enable = 1;

err_code = sd_ble_opt_set(BLE_GAP_OPT_COMPAT_MODE_2,&ble_opt);

APP_ERROR_CHECK(err_code);