Hi Ray
the shield is being used with a Sain Smart mega 2560 not an Uno - will try to find a link
but its an Arduino mega copy as far as I know - with my limited experience
shield fits all pins on main board
I bought them because of the number of outputs available as i need to control a few servo's
model railway layout point /switch control even including the cost of the 2 boards and 30 plus servos/steppers, its still going to be cheaper than commercial point motors and control circuitry
Ok so I'm an anorak - lol, English sense of humour, - no offense to anoraks intended or implied