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Category Archives: NodeMCU
Building your own weather station is a fun project in itself, but building it to be self-sufficient and off-grid adds another set of challenges to the mix. You’ll need a battery and a solar panel to power the station, which means adding at least a regulator and charge controller to your build. If the panel and battery are small, you’ll also need to make some power-saving tweaks to the code as well. (Google Translate from Italian) The tricks that [Danilo Larizza] uses in his build are useful for more than just weather stations though, they’ll be perfect for anyone trying …read more
A stereo setup assumes that the listener is physically located between the speakers, that’s how it can deliver sound equally from both sides. It’s also why the receiver has a “Balance” adjustment, so the listener can virtually move the center point of the audio by changing the relative volume of the speakers. You should set your speaker balance so that your normal sitting location is centered, but of course you might not always be in that same position every time you listen to music or watch something.
[Vije Miller] writes in with his unique solution to the problem of the …read more
Oh, there was a time when you could prototype just about everything on a breadboard. The CPU in your computer came in a DIP package, and there were no BGA packages. to be found anywhere. In the forty years since then, chips have gotten smaller, packages have gotten more cramped, and you can barely hand-solder the coolest chips anymore. No worries — companies are still spitting out dev boards with 0.1″ headers, but there’s a problem: they don’t fit on a solderless breadboard. They’re too wide. Our world is falling apart.
[Luc] had a problem when he was playing with …read more
I’ve always considered barcodes to be one of those invisible innovations that profoundly changed the world. What we might recognize as modern barcodes were originally designed as a labor-saving device in the rail and retail industries, but were quickly adopted by factories for automation, hospitals to help prevent medication errors, and a wide variety of other industries to track the movements of goods.
The technology is accessible, since all you really need is a printer to make barcodes. If you’re already printing packaging for a product, it only costs you ink, or perhaps a small sticker. Barcodes are so ubiquitous …read more
A few weeks ago, [HariFun] set out to emulate a 7-segment display with an LED matrix. Seems easy enough, right? Right. He also wanted to come up with a new way to transition between digits, which is a much harder task. But he did it, and it’s really cool. At a viewer’s suggestion, [Hari] used the transition as the basis for a mesmerizing clock that brings the smooth sweep of an analog second-hand into the digital age.
This is the coolest way to watch the time pass since the hourglass. You can almost hear the light move as one digit …read more
Has the food in your pantry turned? Sometimes it’s the sickening smell of rot that tells you there’s something amiss. But is there a way to catch this before it makes life unpleasant? If only there were machines that could smell spoiled food before it stinks up the whole place.
In early May, I was lucky enough to attend the fourth FabLab Asia Network Conference (Fan4). The theme of their event this year was ‘Co-Create a Better World’. One of the major features of the conference was that there were a number of projects featured, often from rural areas, that …read more
Recently, we covered how to use the Etherscan API to query data (a wallet balance) from the Ethereum blockchain with NodeMCU. It’s a very useful method for retrieving information from a blockchain on embedded systems where storage and memory are an issue.
It has some limitations though. Most notably, it’s polling the API at some interval to retrieve information whether it has changed or not. I would like to be able to receive data more efficiently than this, and quickly enough to make simple vending machines possible. While we’ve seen videos of Bitcoin-based Red Bull vending machines before, they required …read more
Blockchains claim to be public, distributed, effectively immutable ledgers. Unfortunately, they also tend to get a little bit huge – presently the Bitcoin blockchain is 194GB and Ethereum weighs in at 444GB. That poses quite an inconvenience for me, as I was looking at making some fun ‘Ethereum blockchain aware’ gadgets and that’s several orders of magnitude too much data to deal with on a microcontroller, not to mention the bandwidth cost if using 3G.
Having imagined a thin device that I could integrate into my mobile phone cover (or perhaps… a wallet?) dealing with the whole blockchain was clearly …read more
Lightning storm detectors have been around for a surprisingly long time. The early designs consisted of a pair of metal bells and a pendulum. When there was a charge applied, for example by connecting one bell to the ground and the other to a lightning rod, the bells would ring when a lightning storm was close by. In the mid 18th century, these devices were only practical for demonstration and research purposes, but very likely represent the earliest devices that convert electrostatic charge to mechanical force. A bit over a hundred years later, the first lightning detector was considered …read more