5.7.1.1.2 DFU Update Request (DFUU…)

Format: DFUU, <hex32>,<hex8>,<hex32>,<hex16>

The DFUU command is initiated to request the new firmware image update. This command accepts three parameters:

First parameter – The total image size, it must be 16-bytes aligned
Second parameter – Encryption status of the image
Third parameter – Flash image ID
Fourth Parameter – CRC-16

The following table provides details for Flash image ID setting.

The RNBD350 responds back with the maximum allowed fragmented image size. The user can pass an image fragment whose size is either less than or equal to the received number.


Example:	`DFUU, 00046400,01,9E000002, 0148`	// DFU update request, the total image size is 0x46400, the image is encrypted and the Flash image ID is 9E000002,and the CRC-16 is 0x0148. The hexadecimal value 0x0148 represents the CRC-16 value, which is obtained from the header section of a `.bin` file. This value is used as an example here.
Response:	`DFUU, 0200`	// Accept update, the allow max fragmented image size is 0x200