Brother MFC-J430W WiFi scanner protocol

Reasons

Brother MFC-J430W has already scanner driver and you can download here but that are prebuilt binary (x86/x64) and source code isn't public. This is a problem if you want to use the scanner on ARM architecture, because if you don't have the source code of the driver you can't recompile it. Anyway this should work on every scanner that use brscan4, but I'm not sure.

Scanning protocol

Color Modes

• GRAY64: gray scale image
• CGRAY: color image
• TEXT: low resolution mode, max output (304x434)

Compressions

• JPEG: JPEG compression
• RLENGTH: Run Length Encoding
• NONE: no compression

Status codes

When we open a connection with the scanner on port 54921, it responds with his status code:

• +OK 200: Ready to use
• -NG 401: Scanner is busy

Lease

Now we can send a request that specify resolution and color mode, then the scanner sends to client an offer, based on request. The ADF is automatically forced when the scanner detects documents in the feeder. I called this part lease because it recalled me DHCP lease.

Response

After we make a request, the scanner sends an offer to client. If we want continue we are ready to start scanning.

dpi(x),dpi(y),adf,mm(x),px(x),mm(y),px(y)

• dpi: dots per inch
• adf: automatic document feeder (1=enabled, 2=disabled)
• mm: millimeters (plane width and height)
• pixels: pixels (image width and height)

Start scan

The request must contains the following payload:

• R = dpi(x), dpi(y)
• M = color mode
• C = compression
• J = MID (?)
• B = brightness
• N = contrast
• A = x1,y1,x2,y2 (area)

NOTE: x2 and y2 are calculated from plane dimensions because width received from response in lease phase is different from width calculated

As you can see the reversing isn't completed at all and i work on it rarely, but work in progress...

Protocol implementation

There are still some work to do to implement all functionalities of the scanner, but the major part is done. In this moment the scanning with image compression isn't implemented.

Compile

git clone https://github.com/v0lp3/mfc-j430w.git
go build -o mfc-j430w mfc-j430w/src/*.go

Usage

./mfc-j430w --help

Output:

Usage of ./mfc-j430w:
  -a string
        IP address of the Brother scanner (default "192.168.0.157")
  -c string
        Color mode of the scan (CGRAY, GRAY64) (default "CGRAY")
  -m    Enable scan of all pages from feeder
  -n string
        Name of the output file (default "scan.jpg")
  -r int
        Resolution of the scan (default 300)

Credits

Andrea Maugeri

Partially thanks to this