ESP32 Weather Station Looks Great With Color E-Paper Display

February 28, 2024 by Lewin Day 20 Comments

[educ8s.tv] has built weather stations before, but his latest is his best yet. It’s all thanks to its low-power design, enabled by its e-paper display.

The build is based around an ESP32 microcontroller, combined with a BMP180 sensor for measuring barometric pressure, and a DHT22 sensor for measuring temperature and humidity. By taking these values and feeding them into the Zambretti algorithm, it’s possible to generate a rudimentary weather forecast.

The weather station looks particularly impressive thanks to its six-color e-paper display. It’s brightly colored and easy to read, and displays graphs of temperature, pressure, and humidity over time. Plus, by virtue of the fact that it only draws power when updating, it allows the project to last a long time running solely on battery power.

As far as DIY weather stations go, this is an attractive and clean design that offers plenty of useful data to the user. We’ve seen some other neat builds in this vein before, too.

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Solar E-Ink Weather Station Works On Dark Days, Too

February 22, 2024 by Kristina Panos 11 Comments

One way to get through the winter doldrums is to take notice of the minuscule positive changes in weather as spring approaches. Although much of the US is experiencing a particularly warm month, that’s not the case in Germany where [rsappiawf] resides. Even so, they are having a good time charting the weather on their new solar-powered E-ink weather station.

And in spite of the dark winter days, the device has been delivering weather updates for over a week on solar power alone. The brains of this operation is an ESP32 S3 Mini, which [rsappiawf] operated on a little bit. For starters, they removed the integrated RGB LED in order to save precious milliamps. Then they upgraded the voltage regulator to a TPS73733DCQR.

[rsappiawf] also has a TPL5110 power timer breakout module in the mix, which saves even more power by only turning on every once in a while according to the potentiometer setting, and only then turning on the project’s power. Check out the brief demo after the break, including the cool sliding action into the 3D-printed holder.

There’s a lot you can do to lower power consumption in a project like this. Here’s one that will go 60 days on a charge.

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Building A Weather Display In Rust

September 29, 2023 by Bryan Cockfield 21 Comments

We’ve seen a lot of weather displays over the years, and plenty of the more modern ones have been using some form of electronic paper. So what makes this particular build from [Harry Stern] different? The fact that the firmware running on the ESP32 microcontroller at its heart was developed in Rust.

The weather station itself is capable of operating for several months on its rechargeable NiMH battery bank. The Rust section of the project is in two parts, the first of which runs on a server which downloads the weather data and aggregates it into an image. The second part runs on the ESP32 using esp-idf which configures peripherals, turns on and connects to Wi-Fi, retrieves the image from the server, displays the image and then puts the display to sleep. By doing the heavy lifting on the server, the display should be able to run for longer than it would if everything was happening on the ESP32.

The project code is available from this GitHub page which should allow even Rust beginners to follow along, and the case file is also available for those with a 3D printer. [Harry] has a few upgrades planned for future releases as well, including a snap-fit case, a custom PCB, and improved voltage regulator for better battery life, and enhanced error handling for the weather API. And Rust isn’t the only interesting part of this project, either. As prices for e-paper displays continue to fall, more and more of them are found in projects like weather stations and even complete laptops which use these displays exclusively.

Weather Station With Distributed Sensors

August 11, 2023 by Bryan Cockfield 2 Comments

Building a weather station is a fairly common project that plenty of us have taken on, and for good reason. They can be built around virtually any microcontroller or full-scale computer, can have as many or few sensors as needed, and range from simple, straightforward projects to more complex systems capable of doing things like sending data off to weather services like Weather Underground. This weather station features a few innovations we don’t often see, though, with a modular and wireless design that makes it versatile and easy to scale up or down as needed.

Each of the modules in this build use the ESP32 platform, which simplifies design and also takes care of the wireless capability needed. The base station gets a few extra sensors including those for carbon dioxide, volatile organic compounds, and nitrogen oxides. It also includes a screen which can be used to display a wide variety of data gathered locally but also includes forecast information fetched from the free OpenWeatherMap API. For the sensor modules, BME280 sensors are used for temperature, pressure, and humidity and each module includes its own solar panel and battery with the ESP32 chips set to operate using as little energy as possible.

One of the things that helps easily integrate all of the sensor modules is the use of ESP-NOW, which we have seen a few times before. It essentially eliminates the need for a router and allows ESP modules to connect directly with one another. The build also goes into detail about most of the aspects of this project including the programming of the GUI that the ESP32 base station displays on its screen, so for anyone looking to start their own weather station project this should be an excellent guide. Make sure to check out this one as well if you want to send all of your weather data to Weather Underground.

DIY 3D Printed Rain Gauge Connects To Home Assistant

May 30, 2023 by Danie Conradie 16 Comments

Measuring local rainfall has real practical uses, especially in agriculture, but most of us will have to admit that it’s at least partly about drawing cool graphs on a screen. Whatever your motivation, you can build this open source electronic rain gauge designed by [Sebastian] of Smart Solutions for Home, and integrate it with Home Assistant.

This 3D printed rain gauge is of the ubiquitous tipping bucket type and uses a magnet and hall effect sensor to detect every time the bucket tips out. The sensor is soldered to a custom PCB with ESP32 configured using ESP Home. By keeping it in deep sleep most of the time and only waking up when the tip of the bucket, [Sebastian] estimates it can run about a year on four AA batteries, depending on rainfall. The hinge mechanism is adjustable to ensure that both buckets will tip with the same volume of water.

FDM 3D printed enclosures are not known for being waterproof, so [Sebastian] coated the PCB with varnish to protect it from moisture. This worked well enough that he could leave it running in a bowl of water for a few hours without any ill effects. The end result looks good and should be able to handle the outdoors for a long time.

Building a weather station is a popular DIY project. Some of the interesting varieties we’ve seen are powered by supercapacitors, show readings on antique analog dials and convert parking distance sensor kit into a wind gauge.

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Low Power Challenge: Weather Station Runs For Months Thanks To E-Ink Display

February 20, 2023 by Robin Kearey 1 Comment

Having a device in your living room that shows weather information is convenient, and building one of those is a great project if you enjoy tinkering with microcontrollers and environmental sensors. It’s also a great way to learn about low-power design, as [x-labz] demonstrated with their e-ink weather station which works for no less than 60 days on a single battery charge. It has a clear display that shows the local temperature and humidity, as well as the weather forecast for the day.

The display is a 4.2″ e-paper module with a resolution of 400 x 300 pixels. It uses just 26 mW of power for a few seconds while it updates its image, and basically zero watts when showing a static picture. It’s driven by a tiny ESP32C3 processor board, which downloads the weather forecast from weatherapi.com every two hours. The indoor climate is measured by an SHT-21 temperature and humidity sensor mounted behind the display, while the outdoor data is gathered by a WiFi-connected sensor installed on [x-labz]’s balcony.

The key to achieving low power usage here is to keep the ESP32 in sleep mode as much as possible. The CPU briefly wakes up once every five minutes to read out the indoor sensor and once every fifteen minutes to gather data from outside, using the relatively power-hungry WiFi module.

To further reduce power consumption, the CPU core is driven at the lowest possible clock speed at all times: 10 MHz when reading the indoor sensor, and 80 MHz when using the WiFi connection. All of this helps ensure that just one 600 mAh lithium battery can keep everything running for those 60 days.

E-ink displays are perfect for text and simple graphics that don’t change too often, which is why they’re very popular in weather stations. With a bit of tweaking though, LCDs can also be optimized for low power.

Comparing Solar Energy Harvesters

October 27, 2022 by Bryan Cockfield 11 Comments

There doesn’t have to be much more to setting up a simple solar panel installation than connecting the panel to a battery. Of course we would at least recommend the use of a battery management system or charge controller to avoid damaging the battery, although in a pinch it’s not always strictly necessary. But these simple systems leave a lot on the table, and most people with any sizable amount of solar panels tend to use a maximum power point tracking (MPPT) system to increase the yield of the panels. For a really tiny installation like [Salvatore] has, you’ll want to take a look at a similar system known as a solar energy harvester.

[Salvatore] is planning to use an energy harvester at his small weather station, which is currently powered by an LDO regulator and a small solar cell. While this is fairly energy efficient, the energy harvesters that he is testing with this build will go far beyond what an LDO is capable of. The circuit actually has two energy harvesters built onto it which allows him to test the capabilities of both before he makes a decision for his weather station. Every amount of energy is critical when using the cell he has on hand, which easily fits in the palm of one’s hand.

The testing of this module isn’t complete yet, but he does have two working prototypes to test in future videos to see which one truly performs the best. For a project of this size, this is a great way to get around the problem of supplying a small amount of power to something remote. For a larger solar panel installation, you’ll definitely want to build an MPPT system though.

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