I had been thinking for a while “It would be nice if there was an electronic remote focuser option for the Nexstar 4SE.” Then recently I saw a post by Astronomy Live on Twitter where he uses an Arduino to control the focus on one of his telescopes.
I discovered multiple kits from different Arduino clone manufacturers, on Amazon, that include most of the components to make this possible! Including the microcontroller, a stepper motor, a stepper motor driver, and other components, some of which don’t have direct use for focusing, but I plan on using them anyway.
Something the kit does not include is a way to connect to it remotely. For that, I found a Wi-Fi module that should enable me to set up a small local web server on the Arduino allowing me to control the steper motor, and adjust the telescope focus. I’ll have to devise a way to mount the stepper motor and all the various components since the scope isn’t designed with that in mind.
I’ve started by documenting which pins the various components used in the examples. I was planning on adding the LCD module that came in the kit, to display information such as what speed I had selected for the focus motor, wifi status, temperature, and humidity as well, or even the status of the wifi connection. Unfortunately, it uses some of the same pins as, the stepper motor controller. Perhaps I’ll be able to figure out another option to display the IP address, maybe by using one of the segmented LED modules.
I’ve already tested the DHT thermometer/humidity module, next I’m going to try the stepper motor, and then the ESP8266 wifi module. Finally, I’ll write a program to combine all 3. I’ll document my progress here on the website, and as appropriate on the YouTube channel.