SEND LESS THAN 20 BYTES BLE APP UART

[lm]

Hello, i would like to know if this is possible to send less than 20bytes per packets, by changing the parameters like BLE_GATT_ATT_MTU_DEFAULT or the max data len. My goal would be this thank you so much in advance. Have a great day. 

[lm]

Hello again i have news, i took off the case app_uart_communication_error and it is working better i can see better data BUT i still have a problem. The application has the data but they are too long to receive because byte per byte is too long so i'm going to make packets of 20 bytes BUT my problem is that i have to clean the buffer first, do you have ideas of how can i do that? Thank you