Datasheet

You can use the AT+BLEUARTFIFO=TX command to check the size of the TX FIFO before

sending data to ensure that you have enough free space available in the buffer.

The TX FIFO has the following size, depending on the firmware version used:

Firmware <=0.6.6: 160 characters wide

Firmware >=0.6.7: 1024 characters wide

Note: The TX FIFO full check will happen for each GATT transaction (of up to 20

bytes of data each), so large data transfers may have multiple 200ms wait states.

It IS possible with large data transfers that part of the payload can be transmitted,

and the command can still produce an ERROR if the FIFO doesn't empty in time in

the middle of the payload transfer (since data is transmitted in maximum 20 byte

chunks). If you need to ensure reliable data transfer, you should always check the