Hi.
I have some Uno /Duemilanove shields that use SPI & I2C connected to the usual pins (D11,12,13 & A4,5).
I need to get these working on a Mega.
Has anyone seen a shield for the Mega with an Uno socket on it which maps the SPI & I2C pins from the Mega locations back to their Uno locations ?
Thanks.
Jon.
No, have not seen it.
But I have seen that some make an modification.
The SPI signals are also on the ISP connector (the 6 pins near the microcontroller). That's how some boards are compatible with both, by using the ISP connector. You have to use wires to reroute the I2C signals.
Yeah. The problem i have is the existing Uno shield covers the ICSP header so i can't easily jumper to it.
I can fudge it by bending the pins of the shield out then running wires to the new Mega pins, but it's not very elegant and I wouldn't be able to put the shield back in an Uno.
I am surprised a converter shield doesn't exist as I see the new Leonardo has different pins for SPI too. Only on the ICSP header so again all the old shield with SPI on 11,12,13 won't work.
Maybe converter shields will become more popular... ? Maybe I should build and sell them 
Jon.
I used a proto shield as an "adapter". It was pretty simple really, just 3 wires soldered to the spi connector on the protoboard and connected with little wires to the corresponding pins on the proto board (11,12,&13). Ignore the 7 segment displays on the proto shield...they aren't being used. Also the soldering job was pretty quick and dirty. I also bent up 2 pins on each side because for some reason this proto shield had an extra 2 pins for each side.
