I know that the header is used on Arduino boards for programming, but it also contains the SPI pins. Some shields for Arduino plug into that header specifically to gain access to the SPI bus. Especially on boards like the Arduino Mega which has the hardware SPI pins located along the extra row of headers, which Arduino Uno shields cannot use. The ICSP header is crucial on the Arduino Mega for using Arduino Uno shields. Without that header, you would need to solder jumpers from pins 50-53 to pins 10-13 on the Uno compatible shield. This lack of a vital feature is holding me back from purchasing the RedBoard Artemis or the Artemis ATP.
Hi Joe,
There is no 2x3 ICSP header on the Artemis boards, unfortunately. We did map the SPI pins to the standard Uno pins (D11-13) so most Arduino shields will connect to the SPI pins on both the [RedBoard Artemis and the [RedBoard Artemis ATP. Just remember that the I/O voltage is only 3.3V on all Artemis products so shields that run at 5V logic will not work with the Artemis without shifting the logic level.](https://www.sparkfun.com/products/15442)](SparkFun RedBoard Artemis - DEV-15444 - SparkFun Electronics)