How to make ble characteristic payload more than 20 chars?

[PHerm]

Hello,I want to make payload with 32 chars in my ble servise, I'm changing it in p2pstm.c like in workshop, but nothing more than 20 chars does't transmits. Also allready tried to change the ATT_MTU value in appConf.h - didn't help. How to do it?

[Vyacheslav]

Hi !

First of all, you need to check that when creating characteristic by aci_gatt_add_char(...), the fourth parameter uint16_t Char_Value_Length have sufficient value, least 32.

Second, ATT_MTU should be at least 7 bytes larger, i.e. >=39 bytes.

Thirdly, peer (another device) must support such MTU. otherwise the data will be truncated.

After that, everything should work.

Regards,

Vyacheslav.