fix image offset howto

How to fix a component offset on a board image?

If you see something like this on a generated board image:

Then you may want to correct it by setting a BOARD_PCB_OFFSET in revision.txt or step3_create_board.sh script. In most cases the components are shifted relatively to the board image by some offset in pixels. You need to measure the offset accurately and specify it as following:

BOARD_PCB_OFFSET=X,Y

(Where X and Y are horizontal and vertical offset in pixels)

One of the best ways to measure the offset is to find a multipin IC like MCU and measure the distance between a thin pin of the circuit and a corresponding pad:

If the components are shifted DOWN (relative to the board image - as on the picture), then you should specify a positive value to correct it, otherwise - use negative value as offset. The same applies to the horizontal offset.