the shield connects the Arduino's hardware SPI pins (D10-13) to the MAX3421E.
The Leonardo DOES NOT have the SPI interface on the same four pins. To use an SPI device with the Leonardo you have to connect through the ICSP header.
the shield connects the Arduino's hardware SPI pins (D10-13) to the MAX3421E.
The Leonardo DOES NOT have the SPI interface on the same four pins. To use an SPI device with the Leonardo you have to connect through the ICSP header.