Hackaday Links: February 21, 2021

Well, that was quite a show! The Perseverance rover arrived on Mars Thursday. Don’t tell the boss, but we spent the afternoon watching the coverage in the house on the big TV rather than slaving away in the office. It …read more

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Casio Watch Gets a MEMS Oscillator Upgrade

We’ve got to admit to being a bit of a Casio G-Shock watch geek. The big, chunky watches were every day carry items that survived everything we dished out, right up until the smartphone made wearing one seem redundant. But others continue to use and abuse G-Shocks, and some brave souls even hack them.

Replacing the standard quartz crystal with a temperature-compensated MEMS oscillator is one hack that [Alex] tried, and it appears to have worked out well. His project write-up doesn’t specify which MEMS oscillator was used, but we suspect it’s the SiT1552 TCXO. With its extremely small size, …read more

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Drifting Instrument Presents Opportunity to Learn about Crystal Oscillators

Sure, we all love fixing stuff, but there’s often a fine line between something that’s worth repairing and something that’s cheaper in the long run to just replace. That line gets blurred, though, when there’s something to be learned from a repair.

This wonky temperature-compensated crystal oscillator is a good example of leaning toward repair just for the opportunity to peek inside. [Kerry Wong] identified it as the problem behind a programmable frequency counter reading significantly low. A TCXO is supposed to output a fixed frequency signal that stays stable over a range of temperatures by using a temperature sensor …read more

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Nanocounter: Frequency Counter with an Android UI

Have you ever started a project, run into an issue, started a new project to solve the issue, and completely forgot about the original project? [Andy] went down a rabbit hole of needing a tool to calibrate an MCU oscillator, but not having an accurate way to measure frequency. Most people would just buy a frequency counter and be done with it, but [Andy] decided to build his own.

The Nanocounter is an accurate, open source frequency counter that uses an Android phone as its display. It’s based on a high accuracy temperature compensated crystal oscillator (TCXO) fed into a …read more

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Improving the RTL-SDR

The RTL-SDR dongle is a real workhorse for radio hacking. However, the 28.8 MHz oscillator onboard isn’t as stable as you might wish. It is fine for a lot of applications and, considering the price, you shouldn’t complain. However, there are some cases where you need a more stable reference frequency.

[Craig] wanted a stable solution and immediately thought of a TCXO (Temperature Compensated “Xtal” Oscillator). The problem is, finding these at 28.8 MHz is difficult and, if you can find them, they are relatively expensive. He decided to make an alternate oscillator using an easier-to-find 19.2 MHz crystal.

How …read more

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