Historically, display technologies have always been power thirsty things. In the past, CRTs and incandescent bulbs sucked down electrons like they were free beer. Eventually, LEDs and LCDs came along and lowered this significantly, but the king of low power display technologies remains ePaper and eInk displays. Only requiring power when refreshing the display, they can be left off indefinitely, drawing little to no current. This is great for low-power builds such as [Andrew Lamchenko’s] miniature hygrometer. (Video, embedded below.)
The build runs on an nRF52811 microcontroller, hooked up to a 1.02″ ePaper display sourced for just $7. A SHT20 temperature and humidity sensor is then queried to sample the ambient conditions, and the results displayed on the screen. The benefit of this is that the device can be powered from a coin cell, and set to update at infrequent intervals – say, once per hour. It can then be checked by the user without having to turn on.
The low-power design means it would be the perfect device for leaving in a guitar case or humidor for months at a time. As a bonus, it’s also capable of Smart Home integration thanks to the Bluetooth capabilities onboard. It would likely be trivial to upgrade this into a tweeting humidor, the likes of which we haven’t seen since 2009!
Nice!
Though I wish the Title Photo showed them with a banana for scale.
A photo shoot with a banana ? no problem!
https://hsto.org/webt/qe/qt/1z/qeqt1zlu1hbwtivsz6epyegjhsy.jpeg
Thank you!
Thank you!
Thank you!
(3 bananas = 3 Thank you!s)
I mean i do think this is kool, But….
Is it a hack or open source? Doesn’t look like it.
Looks like you can buy it on ebay tho!.
https://www.ebay.com/itm/Mini-temperature-sensor-with-E-Ink-1-02/203286989350?hash=item2f54d94a26:g:fD4AAOSw0kdgImvC
Actually if you’d read the ebay ad, it appears to be from the builder (mentions swappable chips, and 3d printed case).
From the youtube link, there’s a github, with a GPL:
” smartboxchannel/EFEKTA-EINK102-TEMP-HUM-MICRO-SENSOR-NRF52 is licensed under the
GNU General Public License v3.0″
I knew it was the maker from mother land Russia.
Missed the link to the github somehow tho. Right on…
Solution searching for a problem? Purchased a set of these 2 years ago and have not had to change the original batteries. https://www.ebay.com/itm/264037870183
Interesting project, but … you can buy Xiaomi LCD hygrometers (temperature and humidity) for 5 bucks a piece, they use LCD instead of ePaper, they run on CR2032 coin cell, have Bluetooth capability for smart home integration and they update values every 5 seconds. One coin cell powers the device for around a year. I don’t think temperature and humidity is something you want to update once an hour, you probably want at least once a minute updates. Unless it’s used in some sealed box where you store valuable devices and low frequency update gives you like 5 years battery life.