Like Jim suggested, you could try using the DRV8825, but you would have to limit the current and will not be able to get the maximum power possible out of your stepper motor. With that in mind, you might consider our Pololu High-Power Stepper Motor Driver 36v4 (which requires an SPI interface) or our Tic 36v4 stepper motor controller instead. Both of these can handle up to approximately 4A per phase without a heat sink or forced airflow.
thank you for your reply. According to what I’ve been able to find, RaspberryPI has 3 spi interfaces (0,1,and 2). Are one or all of these the interfaces you are referring to with the 36v4?
Raspberry Pis do have multiple SPI buses that you could probably use to configure and control our high-power 36v4 drivers. (Also, in case you need to control many stepper motor controllers, keep in mind that you can connect multiple devices to a single SPI bus.) There is more information about the driver’s SPI interface on its product page and in the driver IC’s datasheet available under the “Resources” tab.