Matthew Petroff https://mpetroff.net mpetroff.net Sun, 05 Nov 2017 18:45:39 +0000 en-US hourly 1 Light Bulb PCB https://mpetroff.net/2017/11/light-bulb-pcb/ https://mpetroff.net/2017/11/light-bulb-pcb/#respond Sun, 05 Nov 2017 18:45:39 +0000 https://mpetroff.net/?p=2538 Continue reading ]]> As part of a Halloween costume (I was a “bright idea”), I designed a light bulb PCB, which was mostly just an excuse to try out PCBmodE. It consists of seven addressable RGB LEDs, an ATtiny85 microcontroller, an ambient light sensor, and a rechargeable battery. The battery and an old hard drive magnet, for mounting the PCB, are attached to the back via double-sided tape. As one might expect, PCBmodeE worked well for this artistic circuit board design, given that it was designed to be used for something like this, but KiCad is much easier to use for just about everything else.

Light Bulb PCB: Front

Light Bulb PCB: Back

The ambient light sensor proved less useful than I had hoped—the LEDs were too bright to use with all but their dimmest settings, and the light sensor’s optimal range didn’t align well with the lightning levels I was interested in. I also should have placed a copper pour behind the soldermask for the majority of the bulb, since it would have made for a better yellow color. Finally, the footprint I made for the microcontroller footprint is too narrow, but it’s close enough that I was still able to solder the microcontroller in place; a slightly wider footprint for the ambient light sensor would have also made soldering easier. Since this was a one-off, and it’s now past Halloween, there’s no reason for me to revise the PCB to fix these shortcomings.

The design files are in a GitHub repository.

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Reserva Nacional Los Flamencos https://mpetroff.net/2017/10/reserva-nacional-los-flamencos/ https://mpetroff.net/2017/10/reserva-nacional-los-flamencos/#respond Tue, 31 Oct 2017 22:44:26 +0000 https://mpetroff.net/?p=2523 Continue reading ]]> While recently in San Pedro de Atacama, Chile, I drove out towards Argentina to look at the national flamingo reserve, which consists of a number of salt lakes (with flamingos). There are also other interesting geologic formations including rocks sticking out of the desert, the “Monjes de la Pacana.” Here are some photos of the reserve.Laguna Aguas Calientes

Monjes de la Pacana

Monjes de la Pacana

Laguna Aguas Calientes

Monjes de la Pacana

Monjes de la Pacana

Monjes de la Pacana

Laguna de Pujsa

Andean Gulls

Laguna de Pujsa

Flamingos at Laguna de Pujsa

Laguna de Pujsa

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Great Smoky Mountains National Park https://mpetroff.net/2017/09/great-smoky-mountains-national-park/ https://mpetroff.net/2017/09/great-smoky-mountains-national-park/#respond Sat, 30 Sep 2017 22:34:35 +0000 https://mpetroff.net/?p=2505 Continue reading ]]> After viewing the total solar eclipse last month, I visited Great Smoky Mountains National Park on the way back from Tennessee, as well as the Cherohala Skyway, parts of the Blue Ridge Parkway, and Mount Mitchell. Here are some photos of the park.

Great Smoky Mountains National Park

Clingmans Dome Observation Tower

View from Clingmans Dome

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Solar Eclipse https://mpetroff.net/2017/08/solar-eclipse/ https://mpetroff.net/2017/08/solar-eclipse/#respond Wed, 30 Aug 2017 00:01:08 +0000 https://mpetroff.net/?p=2484 Continue reading ]]> Last week, I watched the total solar eclipse from eastern Tennessee, across the Tennessee River from the Watts Bar Nuclear Plant. I was originally planning on watching it from the mountains on the border between Tennessee and North Carolina, but the cloud cover forecast the day of predicted much better weather farther west.

Partial Eclipse

Partial Eclipse

Diamond Ring

Corona at Totality

Totality

Totality

Partial Eclipse

Partial Eclipse

Partial Eclipse

I also took a 360 degree panoramic timelapse as well as a near-infrared timelapse. Unfortunately, the Ricoh Theta S recording the panoramic timelapse stopped recording during totality, and I wasn’t able to fit the sun in the frame of the near-infrared timelapse.

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Solar Filter Holder https://mpetroff.net/2017/07/solar-filter-holder/ https://mpetroff.net/2017/07/solar-filter-holder/#respond Mon, 31 Jul 2017 23:21:24 +0000 https://mpetroff.net/?p=2471 Continue reading ]]> With a total solar eclipse in the continental United States coming up next month, I purchased a solar filter for my telephoto lens. Unfortunately, this OD 5.0 solar filter, which is required for safe optical viewing is much too dark for optimal photography. This led me to purchase a sheet of OD 3.8 photographic solar filter film (from Europe, since no one seems to sell it in the United States). This film requires a holder, and while I could have made a paper holder, I opted to 3D print one instead. By making the inside diameter slightly larger than the lens’ outside diameter, it fits in place snuggly, and is much sturdier than a paper holder. The film is cut to size and sandwiched between the two 3D printed segments using double-sided tape. The screws I used in the first holder proved unnecessary, so I left them out on the second holder I made.

Solar Filter Holders
Solar Filter Holder on Lens

Both holders were printed using PETG, since that’s what I had on hand.

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