pimoco
Telescope mount and focuser control with a Raspberry Pi
Motivation
Why do we need a separate device to control stepper motors attached to a telescope? Often times, a Raspberry Pi 4 running Ekos/Kstars/Indi will be attached to the telescope anyway, providing plenty of compute power. Modern stepper motor controllers like the Trinamic TMC5160 have an on-board motion controller which accepts position read, set target speed and go-to commands via SPI. The Raspberry Pi has two such interfaces for a total of five devices on its GPIO port.
This is
- capable (1/256 microsteps, up to 1000x sidereal slewing, silent tracking, load-adaptive speed w/o step loss)
- robust (no Wifi, Bluetooth or USB connections to the mount as a source of error)
- beautiful (supports SkySafari on phones/tablets and game controllers via Ekos/Kstars/Indi)
- inexpensive (no need for separate microcontrollers like OnStep or TeenAstro)
- manageable (no separate device firmware, only Indi drivers which Linux package managers can update)