Postcard from the Summit – Cleaning a Mirror
Author: Andrew
An electrical engineer, amateur astronomer, and diver, living and working on the island of Hawaiʻi.
Brush Fire near Kaloko
A big brush fire in Kona today, just north of Kaloko. We were in the area for some diving and a few errands in Kona. A lot of fire department equipment responding, plus the helicopter doing air drops.
Mars and Jupiter
Look for the pair to rise about 4:13am, almost two hours before the Sun. The two planets will be 20 degrees above the horizon at sunrise. They should be easy to spot with Jupiter at -2 magnitude and Mars dimmer but still easy at 1.5 magnitude. Look 8° below the pair for Mercury still rising towards maximum elongation.
Bloody Hermit Crab
Postcard from Hawai‘i – Waikoloa Sunset
Mercury Appears in the Dawn
Mercury will begin a morning apparition this week. The planet is currently about 10° above the rising Sun, climbing higher each morning. Look for a 3rd magnitude star-like object just above the glow of dawn. Mercury will reach a maximum elongation of 19° on July 29th.
Mars and Jupiter
Over the next few mornings Mars and Jupiter will rendezvous in the dawn sky. This morning sees the two a little over 2° apart. Over the next few days that will narrow quickly with close approach occurring on the mornings of July 21st and 22nd with about 50′ of separation between the two planets. By the 26th the distance between the pair will again have grown to over 2°.
Throughout the encounter the two planets will precede the Sun by about 25°, rising about 04:00HST, well placed for observation.
Keep an eye out for Mercury below the pairing, a 2nd magnitude object about halfway between the conjunction and the rising Sun. The innermost planet will reach maximum elongation on July 29th.
The mornings of August 3rd and 4th will see a thin crescent Moon slide along the line of three planets in the dawn.
Shark!
The Coathanger Cr399 and NGC6802
The bright stars of Collinder 399 form the Coathanger asterism. Also visible is the open cluster NGC6802 at the left of center. North is up in this view.
Raspberry Pi, Python and SPI
It has only taken me much of the day to get it working. Hours spent reading documentation, searching for postings on the same issue, ripping up the code and trying completely different approaches. Hours of frustration mixed with some solid learning.
Victory was seen in three bytes.
Three bytes shown on the logic analyzer display and in the Python console window. The same three bytes… The hardware and software agreed. The serial timing also looked great, chip select going low when it was supposed to, a 500kHz clock, all of the edges just as the data sheet specified.
Victory is connecting an eight channel A/D converter IC to a Raspberry Pi computer with the hardware SPI module. Four channels for voltages, four channels for temperatures. The project is coming along nicely. Will talk about what in a later posting. Meantime my thanks to Connor Wolf, Louis Thiery, and Brian Hensley. It was their method and SPI code that worked!
A small victory, another step forward, this is what hackers and makers do…
