Rather than just cramming the Pi and a cheap LCD into his Numworks graphing calculator, ... The first part of the battle was re-configuring the GPIO pins and DMA controller.

If PI controller is needed a good value to start with would be ~0.5 for both RA and Dec. ... If this does not help and there is a drift or the mount PE is still visible in the guiding graph, as shown ...

As with most speed control systems based on FOC, this diagram utilizes three PI controllers; two for controlling the quadrature components of current, and one for controlling the velocity. The design ...