This is a short video demonstrating how to use a Hall Effect sensor and a magnet to implement Periodic Error Correction (PEC).

Here is an example on eBay for a standalone 3144 Hall Effect Sensor. And here are the small neodymium magnets.

This is a time lapse video of Comet Iwamoto C/2018 Y1, on February 22nd 2019, racing against the background stars of the skies. Note that the comet occults two stars during this video. This is a composite of 51 exposures of 60 seconds each, at ISO 800. Taken using a Celestron C8 with a 0.6X reducer on a Vixen SXD mount running OnStep, and a Canon T4i DSLR.

This is a composite video of Comet 46/P Wirtanen done from 41 exposures of 30 seconds each.

They were taken on 2019-12-19, using a Vixen SXD mount converted to OnStep, a Celestron C8 with 0.6X reducer, and a Canon T4i DSLR. You can see the comet racing against the background stars.

An Artificial Star is a point source of light. It is used to simulate a real star indoors, so you can collimate your telescope's optics indoors and/or during daylight.

Commercial artificial stars, such as this Hubble Optics one, cost $25 or more, and their main feature is a small plate that has precision holes of 50 micron up to 250 microns.

You can make your own artificial star, which is very close in function to the commercial ones.

You can watch this short 4 minute video on how I did it, and read on for detailed instructions.

If you have been experiencing audio skips or stuttering on a Raspberry Pi, then I may have a solution for you.

For background, I use an older Raspberry Pi as an audio player, using mpd as an audio server, MPD Remote on my Android Phone, and Sonata on my Xubuntu Laptop.

It was working fine for a long time, but then it started skipping audio every 10 or 20 seconds, regularly.

In December 2018, Dave Schwartz completed a design for a Smart Hand Controller (SHC) for the OnStep open source telescope controller.

After completing the hardware, I ported the firmware for it, from the Teensy 3.x to the lower cost ESP32.

Here is a video that I did demonstrating the features.

Last Monday, I gave a talk at the KWLUG on Microcontrollers and The Internet of Things (IoT).

It covered topics such as: how microcontrollers are different from 'computers', the Arduino and Arduino IDE, the ESP8266 and ESP32 WiFi enabled microcontrollers, and using MicroPython on them. Also covered the very low cost STM32 ARM Cortex microcontroller.

After nine months of modifying the OnStep open source telescope controller to run on the cheap STM32 ARM Cortex M3 microcontroller, it is time to reap the fruits of this long labour: I have an OnStep powered mount ...

A while back, I completed a port of the open source OnStep Telescope Controller firmware to the STM32 Blue Pill ARM Cortex M3 32-bit MCU. Later, Dave Schwartz and myself designed a Printed Circuit Board (PCB) that makes building a controller a far easier task than before.

Here is a video of the completed PCB.

What happens when aboriginal people who are living a hunter/gatherer or farmer life style come face to face with 20th century technology and civilization too quickly? Their minds could not fathom the rest of earth's human civilization gradual progression over the past 5,000 or so years.

The people of Tanna island of Vanuatu suddenly woke up during World War II to the U.S. Navy establishing airfields, forward bases, and housing close to 250,000 people, with all the necessary support services, including telephone and cinemas.