E ink (additionally known as ePaper) shows appear nearly magical, as a result of they solely require energy when refreshing the content material of the display. In the event that they’re displaying a static picture, they don’t draw any energy in any respect. Mix that with unbelievable distinction and the know-how could be very fascinating for sure purposes—significantly low-power gadgets that don’t replace typically. That made an E Ink display the right selection for Ricardo Sappia’s solar-powered climate station.
E Ink screens have two main disadvantages. The primary is that they’re gradual to refresh, with some fashions taking a second or longer to replace the whole display. The second is that almost all fashions are monochrome. There are some that may show a handful of colours, however they’ve even slower refresh charges than their black-and-white cousins. On this case, neither of these disadvantages are sensible considerations. This system shows detailed details about the day’s climate situations and that data doesn’t want to vary typically. The one exception is the clock within the nook that should replace as soon as per minute, however that solely requires a partial refresh.
As a result of Sappia selected an E Ink display, this climate station consumes little or no energy and so it will probably get all the vitality it wants from the solar. Sappia designed the system to sit down towards a window the place a small photo voltaic panel on the again of the enclosure can obtain good publicity to daylight. Throughout daylight, that recharges a small LiPo battery that retains the system going via the evening. An ESP32 improvement board pulls climate data from the web and exhibits that on the E Ink display, going right into a power-saving deep sleep mode between updates.
This explicit E Ink show is a 2.13” tri-color mannequin from Wemos with a decision of 250×122. It may show white, black, and pink pixels. Sappia designed a complete GUI that shows the time, date, moon state, dawn time, sundown time, temperature highs and lows all through the day, wind velocity and route, and cloud cowl situations. Most of that’s black and white, however Sappia used pink in just a few locations (resembling to signify the solar).
All of these parts slot in a tidy 3D-printed enclosure that Sappia can place on a window body.