ArduinoSoftSpi
We are releasing Arduino code that enables the use of an SD-card and an APA102/spi led strip on the Teensy 3.1 (and other arduino) platforms.
This one-header library specifies a highly optimized software implementation of SPI. This ArduionSoftSpi is estimated to be able to drive two thousand APA102 pixels @ ~30 fps, based on a test of 435 pixels running at 4ms refresh rate on a Teensy 3.1.
Using a software implementation of spi eliminates the SPI conflict when attempting to drive the APA102 leds and also reading from an SdCard.
This code was pulled from a beta implementation of another library.
Git it here:
Zackees
PS: We forgot which library we pulled this code from. It definitely wasn't us who wrote it originally. If anyone recognizes the original code please send us a link so that we can amend the attribution!