Gray Code-Based Absolute Encoder Design Using Arduino Uno and Its Application for the Hour Angle Axis of the Zeiss Double Refractor Telescope, Bosscha Observatory, Lembang
Naila Atha Nuryaman (a), Maman Sulaeman (b), Mochamad Irfan (b)

a) Astronomy Major, Institut Teknologi Bandung
Jalan Ganesha 10, Bandung 40132, Indonesia
b) Bosscha Observatory
Jl. Peneropongan Bintang No.45, Lembang 40391, Indonesia

Abstract

One of the challenges in manual telescope aiming and control is the limited ability of the observer to accurately determine the angular position of the telescope in real-time. To address this problem, a Gray code-based absolute encoder system has been designed, connected to an Arduino Uno microcontroller board. This absolute encoder is designed to read the angular position of the hour angle axis of Zeiss Double Refractor Telescope at the Bosscha Observatory in Lembang, with fixed angular accuracy of up to 0.25 degrees of arc, or 1 minute of hour angle. The system uses a combination of optical sensors and a 10-bit Gray code disk to generate a unique digital signal at each angular position. This digital signal will then be read by the Arduino Uno, which will convert it into the actual angular value of the position of the telescope. By using this method, the hour angle position can be directly and accurately monitored and can be used as a basis for future integration of the motion control system of a telescope, especially the ones with similar mounting system as Zeiss Double Refractor Telescope.

Keywords: Absolute encoder- Gray code- Arduino Uno- hour angle

Topic: Instrumentation in Astronomy