In 2011, I have acquired a 1990 model Kenko NES mount. The mount was sold to me for only 140 USD because it has some missing parts, particularly, the counterweight and the hand controller. The counterweight was easy to replace. Fabricating one only requires a visit to a machine shop. The hand controller that will drive the stepper, however, is far difficult to build.

My first version of a stepper controller uses a 555 timer chip and a 74LS194 shift register. The tracking rate is controlled by the 555 timer chip through a resistor and a capacitor, and by changing the values, the tracking rate also changes. The solution was to use a variable resistor to speed up and slow down the rotation of the stepper. Since the timing signals are controlled by analog components, the tracker suffers from tracking issues related to the tracking rate. It usually requires ‘tracking rate adjustment’ (to match the movement of the sky) at the start of an imaging session. While it has served me for four years and have used it to image some interesting targets, it is clear that an upgrade is needed.

Upon learning some basics about Arduino, I immediately saw the potential to use it as a stepper motor controller. I started looking at some excellent tutorials on the Internet and was able to build the simple stepper controller featured in this article.

arduino stepper

DIY Stepper Motor Controller

To learn more about the DIY Stepper Motor Controller, click here.

For featured photos, click here.
For tutorials on how to get started with astrophotography, click here.
For DIY astronomy projects useful for astrophotography, click here.
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© Anthony Urbano (Manila, Philippines)

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